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postgresql/src/include/access/xlog.h

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Transaction log manager core code. It doesn't work currently but also don't break anything -:)
1999-09-27 17:48:12 +02:00
/*
* xlog.h
*
Replace "transaction log" with "write-ahead log" This makes documentation and error messages match the renaming of "xlog" to "wal" in APIs and file naming.
2017-05-12 17:49:56 +02:00
* PostgreSQL write-ahead log manager
Transaction log manager core code. It doesn't work currently but also don't break anything -:)
1999-09-27 17:48:12 +02:00
*
Update copyright for 2019 Backpatch-through: certain files through 9.4
2019-01-02 18:44:25 +01:00
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
XLOG (and related) changes: * Store two past checkpoint locations, not just one, in pg_control. On startup, we fall back to the older checkpoint if the newer one is unreadable. Also, a physical copy of the newest checkpoint record is kept in pg_control for possible use in disaster recovery (ie, complete loss of pg_xlog). Also add a version number for pg_control itself. Remove archdir from pg_control; it ought to be a GUC parameter, not a special case (not that it's implemented yet anyway). * Suppress successive checkpoint records when nothing has been entered in the WAL log since the last one. This is not so much to avoid I/O as to make it actually useful to keep track of the last two checkpoints. If the things are right next to each other then there's not a lot of redundancy gained... * Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs on alternate bytes. Polynomial borrowed from ECMA DLT1 standard. * Fix XLOG record length handling so that it will work at BLCKSZ = 32k. * Change XID allocation to work more like OID allocation. (This is of dubious necessity, but I think it's a good idea anyway.) * Fix a number of minor bugs, such as off-by-one logic for XLOG file wraparound at the 4 gig mark. * Add documentation and clean up some coding infelicities; move file format declarations out to include files where planned contrib utilities can get at them. * Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also possible to force a checkpoint by sending SIGUSR1 to the postmaster (undocumented feature...) * Defend against kill -9 postmaster by storing shmem block's key and ID in postmaster.pid lockfile, and checking at startup to ensure that no processes are still connected to old shmem block (if it still exists). * Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency stop, for symmetry with postmaster and xlog utilities. Clean up signal handling in bootstrap.c so that xlog utilities launched by postmaster will react to signals better. * Standalone bootstrap now grabs lockfile in target directory, as added insurance against running it in parallel with live postmaster.
2001-03-13 02:17:06 +01:00
* Portions Copyright (c) 1994, Regents of the University of California
*
Remove cvs keywords from all files.
2010-09-20 22:08:53 +02:00
* src/include/access/xlog.h
Transaction log manager core code. It doesn't work currently but also don't break anything -:)
1999-09-27 17:48:12 +02:00
*/
#ifndef XLOG_H
#define XLOG_H
#include "access/rmgr.h"
WAL
2000-10-28 18:21:00 +02:00
#include "access/xlogdefs.h"
Move the backup-block logic from XLogInsert to a new file, xloginsert.c. xlog.c is huge, this makes it a little bit smaller, which is nice. Functions related to putting together the WAL record are in xloginsert.c, and the lower level stuff for managing WAL buffers and such are in xlog.c. Also move the definition of XLogRecord to a separate header file. This causes churn in the #includes of all the files that write WAL records, and redo routines, but it avoids pulling in xlog.h into most places. Reviewed by Michael Paquier, Alvaro Herrera, Andres Freund and Amit Kapila.
2014-11-06 12:52:08 +01:00
#include "access/xloginsert.h"
Revamp the WAL record format. Each WAL record now carries information about the modified relation and block(s) in a standardized format. That makes it easier to write tools that need that information, like pg_rewind, prefetching the blocks to speed up recovery, etc. There's a whole new API for building WAL records, replacing the XLogRecData chains used previously. The new API consists of XLogRegister* functions, which are called for each buffer and chunk of data that is added to the record. The new API also gives more control over when a full-page image is written, by passing flags to the XLogRegisterBuffer function. This also simplifies the XLogReadBufferForRedo() calls. The function can dig the relation and block number from the WAL record, so they no longer need to be passed as arguments. For the convenience of redo routines, XLogReader now disects each WAL record after reading it, copying the main data part and the per-block data into MAXALIGNed buffers. The data chunks are not aligned within the WAL record, but the redo routines can assume that the pointers returned by XLogRecGet* functions are. Redo routines are now passed the XLogReaderState, which contains the record in the already-disected format, instead of the plain XLogRecord. The new record format also makes the fixed size XLogRecord header smaller, by removing the xl_len field. The length of the "main data" portion is now stored at the end of the WAL record, and there's a separate header after XLogRecord for it. The alignment padding at the end of XLogRecord is also removed. This compansates for the fact that the new format would otherwise be more bulky than the old format. Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera, Fujii Masao.
2014-11-20 16:56:26 +01:00
#include "access/xlogreader.h"
Move Timestamp/Interval typedefs and basic macros into datatype/timestamp.h. As per my recent proposal, this refactors things so that these typedefs and macros are available in a header that can be included in frontend-ish code. I also changed various headers that were undesirably including utils/timestamp.h to include datatype/timestamp.h instead. Unsurprisingly, this showed that half the system was getting utils/timestamp.h by way of xlog.h. No actual code changes here, just header refactoring.
2011-09-09 19:23:41 +02:00
#include "datatype/timestamp.h"
Arrange to emit a description of the current XLOG record as error context when an error occurs during xlog replay. Also, replace the former risky 'write into a fixed-size buffer with no overflow detection' API for XLOG record description routines; use an expansible StringInfo instead. (The latter accounts for most of the patch bulk.) Qingqing Zhou
2006-03-24 05:32:13 +01:00
#include "lib/stringinfo.h"
Map basebackup tablespaces using a tablespace_map file Windows can't reliably restore symbolic links from a tar format, so instead during backup start we create a tablespace_map file, which is used by the restoring postgres to create the correct links in pg_tblspc. The backup protocol also now has an option to request this file to be included in the backup stream, and this is used by pg_basebackup when operating in tar mode. This is done on all platforms, not just Windows. This means that pg_basebackup will not not work in tar mode against 9.4 and older servers, as this protocol option isn't implemented there. Amit Kapila, reviewed by Dilip Kumar, with a little editing from me.
2015-05-12 15:29:10 +02:00
#include "nodes/pg_list.h"
#include "storage/fd.h"
Transaction log manager core code. It doesn't work currently but also don't break anything -:)
1999-09-27 17:48:12 +02:00
To support external compression of archived WAL data, add a flag bit to WAL records that shows whether it is safe to remove full-page images (ie, whether or not an on-line backup was in progress when the WAL entry was made). Also make provision for an XLOG_NOOP record type that can be used to fill in the extra space when decompressing the data for restore. This is the portion of Koichi Suzuki's "full page writes" patch that has to go into the core database. The remainder of that work is two external compression and decompression programs, which for the time being will undergo separate development on pgfoundry. Per discussion. Also, twiddle the handling of BTREE_SPLIT records to ensure it'll be possible to compress them (the previous coding caused essential info to be omitted). The other commonly-used record types seem OK already, with the possible exception of GIN and GIST WAL records, which I don't understand well enough to opine on.
2007-05-20 23:08:19 +02:00
Add support for wal_fsync_writethrough for Darwin, and restructure the code to better handle writethrough. Chris Campbell
2005-05-20 16:53:26 +02:00
/* Sync methods */
#define SYNC_METHOD_FSYNC 0
#define SYNC_METHOD_FDATASYNC 1
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
#define SYNC_METHOD_OPEN 2 /* for O_SYNC */
Add support for wal_fsync_writethrough for Darwin, and restructure the code to better handle writethrough. Chris Campbell
2005-05-20 16:53:26 +02:00
#define SYNC_METHOD_FSYNC_WRITETHROUGH 3
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
#define SYNC_METHOD_OPEN_DSYNC 4 /* for O_DSYNC */
Add support for wal_fsync_writethrough for Darwin, and restructure the code to better handle writethrough. Chris Campbell
2005-05-20 16:53:26 +02:00
extern int sync_method;
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
extern PGDLLIMPORT TimeLineID ThisTimeLineID; /* current TLI */
Allow read only connections during recovery, known as Hot Standby. Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
/*
Replace max_standby_delay with two parameters, max_standby_archive_delay and max_standby_streaming_delay, and revise the implementation to avoid assuming that timestamps found in WAL records can meaningfully be compared to clock time on the standby server. Instead, the delay limits are compared to the elapsed time since we last obtained a new WAL segment from archive or since we were last "caught up" to WAL data arriving via streaming replication. This avoids problems with clock skew between primary and standby, as well as other corner cases that the original coding would misbehave in, such as the primary server having significant idle time between transactions. Per my complaint some time ago and considerable ensuing discussion. Do some desultory editing on the hot standby documentation, too.
2010-07-03 22:43:58 +02:00
* Prior to 8.4, all activity during recovery was carried out by the startup
Allow read only connections during recovery, known as Hot Standby. Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
* process. This local variable continues to be used in many parts of the
Replace max_standby_delay with two parameters, max_standby_archive_delay and max_standby_streaming_delay, and revise the implementation to avoid assuming that timestamps found in WAL records can meaningfully be compared to clock time on the standby server. Instead, the delay limits are compared to the elapsed time since we last obtained a new WAL segment from archive or since we were last "caught up" to WAL data arriving via streaming replication. This avoids problems with clock skew between primary and standby, as well as other corner cases that the original coding would misbehave in, such as the primary server having significant idle time between transactions. Per my complaint some time ago and considerable ensuing discussion. Do some desultory editing on the hot standby documentation, too.
2010-07-03 22:43:58 +02:00
* code to indicate actions taken by RecoveryManagers. Other processes that
* potentially perform work during recovery should check RecoveryInProgress().
* See XLogCtl notes in xlog.c.
Allow read only connections during recovery, known as Hot Standby. Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
*/
pgindent run. Make it all clean.
2001-03-22 05:01:46 +01:00
extern bool InRecovery;
Allow read only connections during recovery, known as Hot Standby. Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
/*
* Like InRecovery, standbyState is only valid in the startup process.
Replace max_standby_delay with two parameters, max_standby_archive_delay and max_standby_streaming_delay, and revise the implementation to avoid assuming that timestamps found in WAL records can meaningfully be compared to clock time on the standby server. Instead, the delay limits are compared to the elapsed time since we last obtained a new WAL segment from archive or since we were last "caught up" to WAL data arriving via streaming replication. This avoids problems with clock skew between primary and standby, as well as other corner cases that the original coding would misbehave in, such as the primary server having significant idle time between transactions. Per my complaint some time ago and considerable ensuing discussion. Do some desultory editing on the hot standby documentation, too.
2010-07-03 22:43:58 +02:00
* In all other processes it will have the value STANDBY_DISABLED (so
Change TRUE/FALSE to true/false The lower case spellings are C and C++ standard and are used in most parts of the PostgreSQL sources. The upper case spellings are only used in some files/modules. So standardize on the standard spellings. The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so those are left as is when using those APIs. In code comments, we use the lower-case spelling for the C concepts and keep the upper-case spelling for the SQL concepts. Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-08-16 06:22:32 +02:00
* InHotStandby will read as false).
Allow read only connections during recovery, known as Hot Standby. Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
*
* In DISABLED state, we're performing crash recovery or hot standby was
Correct sundry errors in Hot Standby-related comments. Fujii Masao
2010-08-13 01:24:54 +02:00
* disabled in postgresql.conf.
Allow read only connections during recovery, known as Hot Standby. Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
*
Replace max_standby_delay with two parameters, max_standby_archive_delay and max_standby_streaming_delay, and revise the implementation to avoid assuming that timestamps found in WAL records can meaningfully be compared to clock time on the standby server. Instead, the delay limits are compared to the elapsed time since we last obtained a new WAL segment from archive or since we were last "caught up" to WAL data arriving via streaming replication. This avoids problems with clock skew between primary and standby, as well as other corner cases that the original coding would misbehave in, such as the primary server having significant idle time between transactions. Per my complaint some time ago and considerable ensuing discussion. Do some desultory editing on the hot standby documentation, too.
2010-07-03 22:43:58 +02:00
* In INITIALIZED state, we've run InitRecoveryTransactionEnvironment, but
* we haven't yet processed a RUNNING_XACTS or shutdown-checkpoint WAL record
* to initialize our master-transaction tracking system.
Allow read only connections during recovery, known as Hot Standby. Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
*
* When the transaction tracking is initialized, we enter the SNAPSHOT_PENDING
* state. The tracked information might still be incomplete, so we can't allow
* connections yet, but redo functions must update the in-memory state when
* appropriate.
*
* In SNAPSHOT_READY mode, we have full knowledge of transactions that are
* (or were) running in the master at the current WAL location. Snapshots
* can be taken, and read-only queries can be run.
*/
typedef enum
{
STANDBY_DISABLED,
STANDBY_INITIALIZED,
STANDBY_SNAPSHOT_PENDING,
STANDBY_SNAPSHOT_READY
} HotStandbyState;
Replace max_standby_delay with two parameters, max_standby_archive_delay and max_standby_streaming_delay, and revise the implementation to avoid assuming that timestamps found in WAL records can meaningfully be compared to clock time on the standby server. Instead, the delay limits are compared to the elapsed time since we last obtained a new WAL segment from archive or since we were last "caught up" to WAL data arriving via streaming replication. This avoids problems with clock skew between primary and standby, as well as other corner cases that the original coding would misbehave in, such as the primary server having significant idle time between transactions. Per my complaint some time ago and considerable ensuing discussion. Do some desultory editing on the hot standby documentation, too.
2010-07-03 22:43:58 +02:00
Allow read only connections during recovery, known as Hot Standby. Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
extern HotStandbyState standbyState;
#define InHotStandby (standbyState >= STANDBY_SNAPSHOT_PENDING)
Adjust comment in .history file to match recovery target specified. Comment present since 8.0 was never fully meaningful, since two recovery targets cannot be specified. Refactor recovery target type to make this change and associated code easier to understand. No change in function. Bug report arising from internal support question.
2010-03-19 12:05:15 +01:00
/*
* Recovery target type.
Integrate recovery.conf into postgresql.conf recovery.conf settings are now set in postgresql.conf (or other GUC sources). Currently, all the affected settings are PGC_POSTMASTER; this could be refined in the future case by case. Recovery is now initiated by a file recovery.signal. Standby mode is initiated by a file standby.signal. The standby_mode setting is gone. If a recovery.conf file is found, an error is issued. The trigger_file setting has been renamed to promote_trigger_file as part of the move. The documentation chapter "Recovery Configuration" has been integrated into "Server Configuration". pg_basebackup -R now appends settings to postgresql.auto.conf and creates a standby.signal file. Author: Fujii Masao <masao.fujii@gmail.com> Author: Simon Riggs <simon@2ndquadrant.com> Author: Abhijit Menon-Sen <ams@2ndquadrant.com> Author: Sergei Kornilov <sk@zsrv.org> Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
2018-11-25 16:31:16 +01:00
* Only set during a Point in Time recovery, not when in standby mode.
Adjust comment in .history file to match recovery target specified. Comment present since 8.0 was never fully meaningful, since two recovery targets cannot be specified. Refactor recovery target type to make this change and associated code easier to understand. No change in function. Bug report arising from internal support question.
2010-03-19 12:05:15 +01:00
*/
typedef enum
{
RECOVERY_TARGET_UNSET,
RECOVERY_TARGET_XID,
Named restore points in recovery. Users can record named points, then new recovery.conf parameter recovery_target_name allows PITR to specify named points as recovery targets. Jaime Casanova, reviewed by Euler Taveira de Oliveira, plus minor edits
2011-02-08 20:39:08 +01:00
RECOVERY_TARGET_TIME,
Add recovery_target='immediate' option. This allows ending recovery as a consistent state has been reached. Without this, there was no easy way to e.g restore an online backup, without replaying any extra WAL after the backup ended. MauMau and me.
2014-01-25 16:34:04 +01:00
RECOVERY_TARGET_NAME,
New recovery target recovery_target_lsn Michael Paquier
2016-09-03 18:48:01 +02:00
RECOVERY_TARGET_LSN,
Add recovery_target='immediate' option. This allows ending recovery as a consistent state has been reached. Without this, there was no easy way to e.g restore an online backup, without replaying any extra WAL after the backup ended. MauMau and me.
2014-01-25 16:34:04 +01:00
RECOVERY_TARGET_IMMEDIATE
Adjust comment in .history file to match recovery target specified. Comment present since 8.0 was never fully meaningful, since two recovery targets cannot be specified. Refactor recovery target type to make this change and associated code easier to understand. No change in function. Bug report arising from internal support question.
2010-03-19 12:05:15 +01:00
} RecoveryTargetType;
Integrate recovery.conf into postgresql.conf recovery.conf settings are now set in postgresql.conf (or other GUC sources). Currently, all the affected settings are PGC_POSTMASTER; this could be refined in the future case by case. Recovery is now initiated by a file recovery.signal. Standby mode is initiated by a file standby.signal. The standby_mode setting is gone. If a recovery.conf file is found, an error is issued. The trigger_file setting has been renamed to promote_trigger_file as part of the move. The documentation chapter "Recovery Configuration" has been integrated into "Server Configuration". pg_basebackup -R now appends settings to postgresql.auto.conf and creates a standby.signal file. Author: Fujii Masao <masao.fujii@gmail.com> Author: Simon Riggs <simon@2ndquadrant.com> Author: Abhijit Menon-Sen <ams@2ndquadrant.com> Author: Sergei Kornilov <sk@zsrv.org> Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
2018-11-25 16:31:16 +01:00
/*
* Recovery target TimeLine goal
*/
typedef enum
{
RECOVERY_TARGET_TIMELINE_CONTROLFILE,
RECOVERY_TARGET_TIMELINE_LATEST,
RECOVERY_TARGET_TIMELINE_NUMERIC
Initial pgindent run for v12. This is still using the 2.0 version of pg_bsd_indent. I thought it would be good to commit this separately, so as to document the differences between 2.0 and 2.1 behavior. Discussion: https://postgr.es/m/16296.1558103386@sss.pgh.pa.us
2019-05-22 18:55:34 +02:00
} RecoveryTargetTimeLineGoal;
Integrate recovery.conf into postgresql.conf recovery.conf settings are now set in postgresql.conf (or other GUC sources). Currently, all the affected settings are PGC_POSTMASTER; this could be refined in the future case by case. Recovery is now initiated by a file recovery.signal. Standby mode is initiated by a file standby.signal. The standby_mode setting is gone. If a recovery.conf file is found, an error is issued. The trigger_file setting has been renamed to promote_trigger_file as part of the move. The documentation chapter "Recovery Configuration" has been integrated into "Server Configuration". pg_basebackup -R now appends settings to postgresql.auto.conf and creates a standby.signal file. Author: Fujii Masao <masao.fujii@gmail.com> Author: Simon Riggs <simon@2ndquadrant.com> Author: Abhijit Menon-Sen <ams@2ndquadrant.com> Author: Sergei Kornilov <sk@zsrv.org> Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
2018-11-25 16:31:16 +01:00
Speedup 2PC by skipping two phase state files in normal path 2PC state info is written only to WAL at PREPARE, then read back from WAL at COMMIT PREPARED/ABORT PREPARED. Prepared transactions that live past one bufmgr checkpoint cycle will be written to disk in the same form as previously. Crash recovery path is not altered. Measured performance gains of 50-100% for short 2PC transactions by completely avoiding writing files and fsyncing. Other optimizations still available, further patches in related areas expected. Stas Kelvich and heavily edited by Simon Riggs Based upon earlier ideas and patches by Michael Paquier and Heikki Linnakangas, a concrete example of how Postgres-XC has fed back ideas into PostgreSQL. Reviewed by Michael Paquier, Jeff Janes and Andres Freund Performance testing by Jesper Pedersen
2016-01-21 03:40:44 +01:00
extern XLogRecPtr ProcLastRecPtr;
Implement lazy XID allocation: transactions that do not modify any database rows will normally never obtain an XID at all. We already did things this way for subtransactions, but this patch extends the concept to top-level transactions. In applications where there are lots of short read-only transactions, this should improve performance noticeably; not so much from removal of the actual XID-assignments, as from reduction of overhead that's driven by the rate of XID consumption. We add a concept of a "virtual transaction ID" so that active transactions can be uniquely identified even if they don't have a regular XID. This is a much lighter-weight concept: uniqueness of VXIDs is only guaranteed over the short term, and no on-disk record is made about them. Florian Pflug, with some editorialization by Tom.
2007-09-05 20:10:48 +02:00
extern XLogRecPtr XactLastRecEnd;
Introduce replication progress tracking infrastructure. When implementing a replication solution ontop of logical decoding, two related problems exist: * How to safely keep track of replication progress * How to change replication behavior, based on the origin of a row; e.g. to avoid loops in bi-directional replication setups The solution to these problems, as implemented here, consist out of three parts: 1) 'replication origins', which identify nodes in a replication setup. 2) 'replication progress tracking', which remembers, for each replication origin, how far replay has progressed in a efficient and crash safe manner. 3) The ability to filter out changes performed on the behest of a replication origin during logical decoding; this allows complex replication topologies. E.g. by filtering all replayed changes out. Most of this could also be implemented in "userspace", e.g. by inserting additional rows contain origin information, but that ends up being much less efficient and more complicated. We don't want to require various replication solutions to reimplement logic for this independently. The infrastructure is intended to be generic enough to be reusable. This infrastructure also replaces the 'nodeid' infrastructure of commit timestamps. It is intended to provide all the former capabilities, except that there's only 2^16 different origins; but now they integrate with logical decoding. Additionally more functionality is accessible via SQL. Since the commit timestamp infrastructure has also been introduced in 9.5 (commit 73c986add) changing the API is not a problem. For now the number of origins for which the replication progress can be tracked simultaneously is determined by the max_replication_slots GUC. That GUC is not a perfect match to configure this, but there doesn't seem to be sufficient reason to introduce a separate new one. Bumps both catversion and wal page magic. Author: Andres Freund, with contributions from Petr Jelinek and Craig Ringer Reviewed-By: Heikki Linnakangas, Petr Jelinek, Robert Haas, Steve Singer Discussion: 20150216002155.GI15326@awork2.anarazel.de, 20140923182422.GA15776@alap3.anarazel.de, 20131114172632.GE7522@alap2.anarazel.de
2015-04-29 19:30:53 +02:00
extern PGDLLIMPORT XLogRecPtr XactLastCommitEnd;
XLOG (and related) changes: * Store two past checkpoint locations, not just one, in pg_control. On startup, we fall back to the older checkpoint if the newer one is unreadable. Also, a physical copy of the newest checkpoint record is kept in pg_control for possible use in disaster recovery (ie, complete loss of pg_xlog). Also add a version number for pg_control itself. Remove archdir from pg_control; it ought to be a GUC parameter, not a special case (not that it's implemented yet anyway). * Suppress successive checkpoint records when nothing has been entered in the WAL log since the last one. This is not so much to avoid I/O as to make it actually useful to keep track of the last two checkpoints. If the things are right next to each other then there's not a lot of redundancy gained... * Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs on alternate bytes. Polynomial borrowed from ECMA DLT1 standard. * Fix XLOG record length handling so that it will work at BLCKSZ = 32k. * Change XID allocation to work more like OID allocation. (This is of dubious necessity, but I think it's a good idea anyway.) * Fix a number of minor bugs, such as off-by-one logic for XLOG file wraparound at the 4 gig mark. * Add documentation and clean up some coding infelicities; move file format declarations out to include files where planned contrib utilities can get at them. * Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also possible to force a checkpoint by sending SIGUSR1 to the postmaster (undocumented feature...) * Defend against kill -9 postmaster by storing shmem block's key and ID in postmaster.pid lockfile, and checking at startup to ensure that no processes are still connected to old shmem block (if it still exists). * Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency stop, for symmetry with postmaster and xlog utilities. Clean up signal handling in bootstrap.c so that xlog utilities launched by postmaster will react to signals better. * Standalone bootstrap now grabs lockfile in target directory, as added insurance against running it in parallel with live postmaster.
2001-03-13 02:17:06 +01:00
Don't set reachedMinRecoveryPoint during crash recovery. In crash recovery, we don't reach consistency before replaying all of the WAL. Rename the variable to reachedConsistency, to make its intention clearer. In master, that was an active bug because of the recent patch to immediately PANIC if a reference to a missing page is found in WAL after reaching consistency, as Tom Lane's test case demonstrated. In 9.1 and 9.0, the only consequence was a misleading "consistent recovery state reached at %X/%X" message in the log at the beginning of crash recovery (the database is not consistent at that point yet). In 8.4, the log message was not printed in crash recovery, even though there was a similar reachedMinRecoveryPoint local variable that was also set early. So, backpatch to 9.1 and 9.0.
2011-12-09 13:32:42 +01:00
extern bool reachedConsistency;
During recovery, if we reach consistent state and still have entries in the invalid-page hash table, PANIC immediately. Immediate PANIC is much better than waiting for end-of-recovery, which is what we did before, because the end-of-recovery might not come until months later if this is a standby server. Also refrain from creating a restartpoint if there are invalid-page entries in the hash table. Restarting recovery from such a restartpoint would not see the invalid references, and wouldn't be able to cross-check them when consistency is reached. That wouldn't matter when things are going smoothly, but the more sanity checks you have the better. Fujii Masao
2011-12-02 09:49:54 +01:00
Support syncing WAL log to disk using either fsync(), fdatasync(), O_SYNC, or O_DSYNC (as available on a given platform). Add GUC parameter to control sync method. Also, add defense to XLogWrite to prevent it from going nuts if passed a target write position that's past the end of the buffers so far filled by XLogInsert.
2001-03-16 06:44:33 +01:00
/* these variables are GUC parameters related to XLOG */
Make WAL segment size configurable at initdb time. For performance reasons a larger segment size than the default 16MB can be useful. A larger segment size has two main benefits: Firstly, in setups using archiving, it makes it easier to write scripts that can keep up with higher amounts of WAL, secondly, the WAL has to be written and synced to disk less frequently. But at the same time large segment size are disadvantageous for smaller databases. So far the segment size had to be configured at compile time, often making it unrealistic to choose one fitting to a particularly load. Therefore change it to a initdb time setting. This includes a breaking changes to the xlogreader.h API, which now requires the current segment size to be configured. For that and similar reasons a number of binaries had to be taught how to recognize the current segment size. Author: Beena Emerson, editorialized by Andres Freund Reviewed-By: Andres Freund, David Steele, Kuntal Ghosh, Michael Paquier, Peter Eisentraut, Robert Hass, Tushar Ahuja Discussion: https://postgr.es/m/CAOG9ApEAcQ--1ieKbhFzXSQPw_YLmepaa4hNdnY5+ZULpt81Mw@mail.gmail.com
2017-09-20 07:03:48 +02:00
extern int wal_segment_size;
Make min_wal_size/max_wal_size use MB internally Previously they were defined using multiples of XLogSegSize. Remove GUC_UNIT_XSEGS. Introduce GUC_UNIT_MB Extracted from patch series on XLogSegSize infrastructure. Beena Emerson
2017-04-05 00:00:01 +02:00
extern int min_wal_size_mb;
extern int max_wal_size_mb;
Rename standby_keep_segments to wal_keep_segments. Also, make the name of the GUC and the name of the backing variable match. Alnong the way, clean up a couple of slight typographical errors in the related docs.
2010-04-20 13:15:06 +02:00
extern int wal_keep_segments;
pgindent run. Make it all clean.
2001-03-22 05:01:46 +01:00
extern int XLOGbuffers;
Rename the parameter recovery_connections to hot_standby, to reduce possible confusion with streaming-replication settings. Also, change its default value to "off", because of concern about executing new and poorly-tested code during ordinary non-replicating operation. Per discussion. In passing do some minor editing of related documentation.
2010-04-29 23:36:19 +02:00
extern int XLogArchiveTimeout;
Add GUC to control the time to wait before retrieving WAL after failed attempt. Previously when the standby server failed to retrieve WAL files from any sources (i.e., streaming replication, local pg_xlog directory or WAL archive), it always waited for five seconds (hard-coded) before the next attempt. For example, this is problematic in warm-standby because restore_command can fail every five seconds even while new WAL file is expected to be unavailable for a long time and flood the log files with its error messages. This commit adds new parameter, wal_retrieve_retry_interval, to control that wait time. Alexey Vasiliev and Michael Paquier, reviewed by Andres Freund and me.
2015-02-23 12:55:17 +01:00
extern int wal_retrieve_retry_interval;
XLOG file archiving and point-in-time recovery. There are still some loose ends and a glaring lack of documentation, but it basically works. Simon Riggs with some editorialization by Tom Lane.
2004-07-19 04:47:16 +02:00
extern char *XLogArchiveCommand;
Rename the parameter recovery_connections to hot_standby, to reduce possible confusion with streaming-replication settings. Also, change its default value to "off", because of concern about executing new and poorly-tested code during ordinary non-replicating operation. Per discussion. In passing do some minor editing of related documentation.
2010-04-29 23:36:19 +02:00
extern bool EnableHotStandby;
Allow pg_basebackup from standby node with safety checking. Base backup follows recommended procedure, plus goes to great lengths to ensure that partial page writes are avoided. Jun Ishizuka and Fujii Masao, with minor modifications
2012-01-25 19:02:04 +01:00
extern bool fullPageWrites;
Rename walLogHints to wal_log_hints for easier grepping. Michael Paquier
2014-01-02 02:17:00 +01:00
extern bool wal_log_hints;
Add GUC to enable compression of full page images stored in WAL. When newly-added GUC parameter, wal_compression, is on, the PostgreSQL server compresses a full page image written to WAL when full_page_writes is on or during a base backup. A compressed page image will be decompressed during WAL replay. Turning this parameter on can reduce the WAL volume without increasing the risk of unrecoverable data corruption, but at the cost of some extra CPU spent on the compression during WAL logging and on the decompression during WAL replay. This commit changes the WAL format (so bumping WAL version number) so that the one-byte flag indicating whether a full page image is compressed or not is included in its header information. This means that the commit increases the WAL volume one-byte per a full page image even if WAL compression is not used at all. We can save that one-byte by borrowing one-bit from the existing field like hole_offset in the header and using it as the flag, for example. But which would reduce the code readability and the extensibility of the feature. Per discussion, it's not worth paying those prices to save only one-byte, so we decided to add the one-byte flag to the header. This commit doesn't introduce any new compression algorithm like lz4. Currently a full page image is compressed using the existing PGLZ algorithm. Per discussion, we decided to use it at least in the first version of the feature because there were no performance reports showing that its compression ratio is unacceptably lower than that of other algorithm. Of course, in the future, it's worth considering the support of other compression algorithm for the better compression. Rahila Syed and Michael Paquier, reviewed in various versions by myself, Andres Freund, Robert Haas, Abhijit Menon-Sen and many others.
2015-03-11 07:52:24 +01:00
extern bool wal_compression;
Add wal_recycle and wal_init_zero GUCs. On at least ZFS, it can be beneficial to create new WAL files every time and not to bother zero-filling them. Since it's not clear which other filesystems might benefit from one or both of those things, add individual GUCs to control those two behaviors independently and make only very general statements in the docs. Author: Jerry Jelinek, with some adjustments by Thomas Munro Reviewed-by: Alvaro Herrera, Andres Freund, Tomas Vondra, Robert Haas and others Discussion: https://postgr.es/m/CACPQ5Fo00QR7LNAcd1ZjgoBi4y97%2BK760YABs0vQHH5dLdkkMA%40mail.gmail.com
2019-04-02 03:37:14 +02:00
extern bool wal_init_zero;
extern bool wal_recycle;
Add WAL consistency checking facility. When the new GUC wal_consistency_checking is set to a non-empty value, it triggers recording of additional full-page images, which are compared on the standby against the results of applying the WAL record (without regard to those full-page images). Allowable differences such as hints are masked out, and the resulting pages are compared; any difference results in a FATAL error on the standby. Kuntal Ghosh, based on earlier patches by Michael Paquier and Heikki Linnakangas. Extensively reviewed and revised by Michael Paquier and by me, with additional reviews and comments from Amit Kapila, Álvaro Herrera, Simon Riggs, and Peter Eisentraut.
2017-02-08 21:45:30 +01:00
extern bool *wal_consistency_checking;
extern char *wal_consistency_checking_string;
Rename the parameter recovery_connections to hot_standby, to reduce possible confusion with streaming-replication settings. Also, change its default value to "off", because of concern about executing new and poorly-tested code during ordinary non-replicating operation. Per discussion. In passing do some minor editing of related documentation.
2010-04-29 23:36:19 +02:00
extern bool log_checkpoints;
Integrate recovery.conf into postgresql.conf recovery.conf settings are now set in postgresql.conf (or other GUC sources). Currently, all the affected settings are PGC_POSTMASTER; this could be refined in the future case by case. Recovery is now initiated by a file recovery.signal. Standby mode is initiated by a file standby.signal. The standby_mode setting is gone. If a recovery.conf file is found, an error is issued. The trigger_file setting has been renamed to promote_trigger_file as part of the move. The documentation chapter "Recovery Configuration" has been integrated into "Server Configuration". pg_basebackup -R now appends settings to postgresql.auto.conf and creates a standby.signal file. Author: Fujii Masao <masao.fujii@gmail.com> Author: Simon Riggs <simon@2ndquadrant.com> Author: Abhijit Menon-Sen <ams@2ndquadrant.com> Author: Sergei Kornilov <sk@zsrv.org> Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
2018-11-25 16:31:16 +01:00
extern char *recoveryRestoreCommand;
extern char *recoveryEndCommand;
extern char *archiveCleanupCommand;
extern bool recoveryTargetInclusive;
extern int recoveryTargetAction;
extern int recovery_min_apply_delay;
extern char *PrimaryConnInfo;
extern char *PrimarySlotName;
/* indirectly set via GUC system */
extern TransactionId recoveryTargetXid;
Don't call data type input functions in GUC check hooks Instead of calling pg_lsn_in() in check_recovery_target_lsn and timestamptz_in() in check_recovery_target_time, reorganize the respective code so that we don't raise any errors in the check hooks. The previous code tried to use PG_TRY/PG_CATCH to handle errors in a way that is not safe, so now the code contains no ereport() calls and can operate safely within the GUC error handling system. Moreover, since the interpretation of the recovery_target_time string may depend on the time zone, we cannot do the final processing of that string until all the GUC processing is done. Instead, check_recovery_target_time() now does some parsing for syntax checking, but the actual conversion to a timestamptz value is done later in the recovery code that uses it. Reported-by: Andres Freund <andres@anarazel.de> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/20190611061115.njjwkagvxp4qujhp%40alap3.anarazel.de
2019-06-30 10:15:25 +02:00
extern char *recovery_target_time_string;
Avoid casting away a const
2019-03-16 10:13:03 +01:00
extern const char *recoveryTargetName;
Integrate recovery.conf into postgresql.conf recovery.conf settings are now set in postgresql.conf (or other GUC sources). Currently, all the affected settings are PGC_POSTMASTER; this could be refined in the future case by case. Recovery is now initiated by a file recovery.signal. Standby mode is initiated by a file standby.signal. The standby_mode setting is gone. If a recovery.conf file is found, an error is issued. The trigger_file setting has been renamed to promote_trigger_file as part of the move. The documentation chapter "Recovery Configuration" has been integrated into "Server Configuration". pg_basebackup -R now appends settings to postgresql.auto.conf and creates a standby.signal file. Author: Fujii Masao <masao.fujii@gmail.com> Author: Simon Riggs <simon@2ndquadrant.com> Author: Abhijit Menon-Sen <ams@2ndquadrant.com> Author: Sergei Kornilov <sk@zsrv.org> Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
2018-11-25 16:31:16 +01:00
extern XLogRecPtr recoveryTargetLSN;
extern RecoveryTargetType recoveryTarget;
extern char *PromoteTriggerFile;
extern RecoveryTargetTimeLineGoal recoveryTargetTimeLineGoal;
extern TimeLineID recoveryTargetTLIRequested;
extern TimeLineID recoveryTargetTLI;
Rename the parameter recovery_connections to hot_standby, to reduce possible confusion with streaming-replication settings. Also, change its default value to "off", because of concern about executing new and poorly-tested code during ordinary non-replicating operation. Per discussion. In passing do some minor editing of related documentation.
2010-04-29 23:36:19 +02:00
Replace checkpoint_segments with min_wal_size and max_wal_size. Instead of having a single knob (checkpoint_segments) that both triggers checkpoints, and determines how many checkpoints to recycle, they are now separate concerns. There is still an internal variable called CheckpointSegments, which triggers checkpoints. But it no longer determines how many segments to recycle at a checkpoint. That is now auto-tuned by keeping a moving average of the distance between checkpoints (in bytes), and trying to keep that many segments in reserve. The advantage of this is that you can set max_wal_size very high, but the system won't actually consume that much space if there isn't any need for it. The min_wal_size sets a floor for that; you can effectively disable the auto-tuning behavior by setting min_wal_size equal to max_wal_size. The max_wal_size setting is now the actual target size of WAL at which a new checkpoint is triggered, instead of the distance between checkpoints. Previously, you could calculate the actual WAL usage with the formula "(2 + checkpoint_completion_target) * checkpoint_segments + 1". With this patch, you set the desired WAL usage with max_wal_size, and the system calculates the appropriate CheckpointSegments with the reverse of that formula. That's a lot more intuitive for administrators to set. Reviewed by Amit Kapila and Venkata Balaji N.
2015-02-23 17:53:02 +01:00
extern int CheckPointSegments;
Integrate recovery.conf into postgresql.conf recovery.conf settings are now set in postgresql.conf (or other GUC sources). Currently, all the affected settings are PGC_POSTMASTER; this could be refined in the future case by case. Recovery is now initiated by a file recovery.signal. Standby mode is initiated by a file standby.signal. The standby_mode setting is gone. If a recovery.conf file is found, an error is issued. The trigger_file setting has been renamed to promote_trigger_file as part of the move. The documentation chapter "Recovery Configuration" has been integrated into "Server Configuration". pg_basebackup -R now appends settings to postgresql.auto.conf and creates a standby.signal file. Author: Fujii Masao <masao.fujii@gmail.com> Author: Simon Riggs <simon@2ndquadrant.com> Author: Abhijit Menon-Sen <ams@2ndquadrant.com> Author: Sergei Kornilov <sk@zsrv.org> Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
2018-11-25 16:31:16 +01:00
/* option set locally in startup process only when signal files exist */
extern bool StandbyModeRequested;
extern bool StandbyMode;
Add archive_mode='always' option. In 'always' mode, the standby independently archives all files it receives from the primary. Original patch by Fujii Masao, docs and review by me.
2015-05-15 17:55:24 +02:00
/* Archive modes */
typedef enum ArchiveMode
{
pgindent run for 9.5
2015-05-24 03:35:49 +02:00
ARCHIVE_MODE_OFF = 0, /* disabled */
ARCHIVE_MODE_ON, /* enabled while server is running normally */
ARCHIVE_MODE_ALWAYS /* enabled always (even during recovery) */
Add archive_mode='always' option. In 'always' mode, the standby independently archives all files it receives from the primary. Original patch by Fujii Masao, docs and review by me.
2015-05-15 17:55:24 +02:00
} ArchiveMode;
extern int XLogArchiveMode;
Introduce wal_level GUC to explicitly control if information needed for archival or hot standby should be WAL-logged, instead of deducing that from other options like archive_mode. This replaces recovery_connections GUC in the primary, where it now has no effect, but it's still used in the standby to enable/disable hot standby. Remove the WAL-logging of "unlogged operations", like creating an index without WAL-logging and fsyncing it at the end. Instead, we keep a copy of the wal_mode setting and the settings that affect how much shared memory a hot standby server needs to track master transactions (max_connections, max_prepared_xacts, max_locks_per_xact) in pg_control. Whenever the settings change, at server restart, write a WAL record noting the new settings and update pg_control. This allows us to notice the change in those settings in the standby at the right moment, they used to be included in checkpoint records, but that meant that a changed value was not reflected in the standby until the first checkpoint after the change. Bump PG_CONTROL_VERSION and XLOG_PAGE_MAGIC. Whack XLOG_PAGE_MAGIC back to the sequence it used to follow, before hot standby and subsequent patches changed it to 0x9003.
2010-04-28 18:10:43 +02:00
/* WAL levels */
typedef enum WalLevel
{
WAL_LEVEL_MINIMAL = 0,
Merge wal_level "archive" and "hot_standby" into new name "replica" The distinction between "archive" and "hot_standby" existed only because at the time "hot_standby" was added, there was some uncertainty about stability. This is now a long time ago. We would like to move forward with simplifying the replication configuration, but this distinction is in the way, because a primary server cannot tell (without asking a standby or predicting the future) which one of these would be the appropriate level. Pick a new name for the combined setting to make it clearer that it covers all (non-logical) backup and replication uses. The old values are still accepted but are converted internally. Reviewed-by: Michael Paquier <michael.paquier@gmail.com> Reviewed-by: David Steele <david@pgmasters.net>
2016-03-01 02:01:54 +01:00
WAL_LEVEL_REPLICA,
Add new wal_level, logical, sufficient for logical decoding. When wal_level=logical, we'll log columns from the old tuple as configured by the REPLICA IDENTITY facility added in commit 07cacba983ef79be4a84fcd0e0ca3b5fcb85dd65. This makes it possible a properly-configured logical replication solution to correctly follow table updates even if they change the chosen key columns, or, with REPLICA IDENTITY FULL, even if the table has no key at all. Note that updates which do not modify the replica identity column won't log anything extra, making the choice of a good key (i.e. one that will rarely be changed) important to performance when wal_level=logical is configured. Each insert, update, or delete to a catalog table will also log the CMIN and/or CMAX values of stamped by the current transaction. This is necessary because logical decoding will require access to historical snapshots of the catalog in order to decode some data types, and the CMIN/CMAX values that we may need in order to judge row visibility may have been overwritten by the time we need them. Andres Freund, reviewed in various versions by myself, Heikki Linnakangas, KONDO Mitsumasa, and many others.
2013-12-11 00:33:45 +01:00
WAL_LEVEL_LOGICAL
Introduce wal_level GUC to explicitly control if information needed for archival or hot standby should be WAL-logged, instead of deducing that from other options like archive_mode. This replaces recovery_connections GUC in the primary, where it now has no effect, but it's still used in the standby to enable/disable hot standby. Remove the WAL-logging of "unlogged operations", like creating an index without WAL-logging and fsyncing it at the end. Instead, we keep a copy of the wal_mode setting and the settings that affect how much shared memory a hot standby server needs to track master transactions (max_connections, max_prepared_xacts, max_locks_per_xact) in pg_control. Whenever the settings change, at server restart, write a WAL record noting the new settings and update pg_control. This allows us to notice the change in those settings in the standby at the right moment, they used to be included in checkpoint records, but that meant that a changed value was not reflected in the standby until the first checkpoint after the change. Bump PG_CONTROL_VERSION and XLOG_PAGE_MAGIC. Whack XLOG_PAGE_MAGIC back to the sequence it used to follow, before hot standby and subsequent patches changed it to 0x9003.
2010-04-28 18:10:43 +02:00
} WalLevel;
Mark wal_level as PGDLLIMPORT. Per buildfarm, this is needed to allow extensions to use XLogIsNeeded() in Windows builds.
2016-05-25 04:48:47 +02:00
extern PGDLLIMPORT int wal_level;
Support syncing WAL log to disk using either fsync(), fdatasync(), O_SYNC, or O_DSYNC (as available on a given platform). Add GUC parameter to control sync method. Also, add defense to XLogWrite to prevent it from going nuts if passed a target write position that's past the end of the buffers so far filled by XLogInsert.
2001-03-16 06:44:33 +01:00
Make postmaster restart archiver soon after it dies, even during recovery. After the archiver dies, postmaster tries to start a new one immediately. But previously this could happen only while server was running normally even though archiving was enabled always (i.e., archive_mode was set to always). So the archiver running during recovery could not restart soon after it died. This is an oversight in commit ffd3774. This commit changes reaper(), postmaster's signal handler to cleanup after a child process dies, so that it tries to a new archiver even during recovery if necessary. Patch by me. Review by Alvaro Herrera.
2015-06-12 16:11:51 +02:00
/* Is WAL archiving enabled (always or only while server is running normally)? */
Add archive_mode='always' option. In 'always' mode, the standby independently archives all files it receives from the primary. Original patch by Fujii Masao, docs and review by me.
2015-05-15 17:55:24 +02:00
#define XLogArchivingActive() \
Merge wal_level "archive" and "hot_standby" into new name "replica" The distinction between "archive" and "hot_standby" existed only because at the time "hot_standby" was added, there was some uncertainty about stability. This is now a long time ago. We would like to move forward with simplifying the replication configuration, but this distinction is in the way, because a primary server cannot tell (without asking a standby or predicting the future) which one of these would be the appropriate level. Pick a new name for the combined setting to make it clearer that it covers all (non-logical) backup and replication uses. The old values are still accepted but are converted internally. Reviewed-by: Michael Paquier <michael.paquier@gmail.com> Reviewed-by: David Steele <david@pgmasters.net>
2016-03-01 02:01:54 +01:00
(AssertMacro(XLogArchiveMode == ARCHIVE_MODE_OFF || wal_level >= WAL_LEVEL_REPLICA), XLogArchiveMode > ARCHIVE_MODE_OFF)
Make postmaster restart archiver soon after it dies, even during recovery. After the archiver dies, postmaster tries to start a new one immediately. But previously this could happen only while server was running normally even though archiving was enabled always (i.e., archive_mode was set to always). So the archiver running during recovery could not restart soon after it died. This is an oversight in commit ffd3774. This commit changes reaper(), postmaster's signal handler to cleanup after a child process dies, so that it tries to a new archiver even during recovery if necessary. Patch by me. Review by Alvaro Herrera.
2015-06-12 16:11:51 +02:00
/* Is WAL archiving enabled always (even during recovery)? */
#define XLogArchivingAlways() \
Merge wal_level "archive" and "hot_standby" into new name "replica" The distinction between "archive" and "hot_standby" existed only because at the time "hot_standby" was added, there was some uncertainty about stability. This is now a long time ago. We would like to move forward with simplifying the replication configuration, but this distinction is in the way, because a primary server cannot tell (without asking a standby or predicting the future) which one of these would be the appropriate level. Pick a new name for the combined setting to make it clearer that it covers all (non-logical) backup and replication uses. The old values are still accepted but are converted internally. Reviewed-by: Michael Paquier <michael.paquier@gmail.com> Reviewed-by: David Steele <david@pgmasters.net>
2016-03-01 02:01:54 +01:00
(AssertMacro(XLogArchiveMode == ARCHIVE_MODE_OFF || wal_level >= WAL_LEVEL_REPLICA), XLogArchiveMode == ARCHIVE_MODE_ALWAYS)
pgindent run for 8.3.
2007-11-15 22:14:46 +01:00
#define XLogArchiveCommandSet() (XLogArchiveCommand[0] != '\0')
XLOG file archiving and point-in-time recovery. There are still some loose ends and a glaring lack of documentation, but it basically works. Simon Riggs with some editorialization by Tom Lane.
2004-07-19 04:47:16 +02:00
Introduce Streaming Replication. This includes two new kinds of postmaster processes, walsenders and walreceiver. Walreceiver is responsible for connecting to the primary server and streaming WAL to disk, while walsender runs in the primary server and streams WAL from disk to the client. Documentation still needs work, but the basics are there. We will probably pull the replication section to a new chapter later on, as well as the sections describing file-based replication. But let's do that as a separate patch, so that it's easier to see what has been added/changed. This patch also adds a new section to the chapter about FE/BE protocol, documenting the protocol used by walsender/walreceivxer. Bump catalog version because of two new functions, pg_last_xlog_receive_location() and pg_last_xlog_replay_location(), for monitoring the progress of replication. Fujii Masao, with additional hacking by me
2010-01-15 10:19:10 +01:00
/*
Introduce wal_level GUC to explicitly control if information needed for archival or hot standby should be WAL-logged, instead of deducing that from other options like archive_mode. This replaces recovery_connections GUC in the primary, where it now has no effect, but it's still used in the standby to enable/disable hot standby. Remove the WAL-logging of "unlogged operations", like creating an index without WAL-logging and fsyncing it at the end. Instead, we keep a copy of the wal_mode setting and the settings that affect how much shared memory a hot standby server needs to track master transactions (max_connections, max_prepared_xacts, max_locks_per_xact) in pg_control. Whenever the settings change, at server restart, write a WAL record noting the new settings and update pg_control. This allows us to notice the change in those settings in the standby at the right moment, they used to be included in checkpoint records, but that meant that a changed value was not reflected in the standby until the first checkpoint after the change. Bump PG_CONTROL_VERSION and XLOG_PAGE_MAGIC. Whack XLOG_PAGE_MAGIC back to the sequence it used to follow, before hot standby and subsequent patches changed it to 0x9003.
2010-04-28 18:10:43 +02:00
* Is WAL-logging necessary for archival or log-shipping, or can we skip
* WAL-logging if we fsync() the data before committing instead?
Introduce Streaming Replication. This includes two new kinds of postmaster processes, walsenders and walreceiver. Walreceiver is responsible for connecting to the primary server and streaming WAL to disk, while walsender runs in the primary server and streams WAL from disk to the client. Documentation still needs work, but the basics are there. We will probably pull the replication section to a new chapter later on, as well as the sections describing file-based replication. But let's do that as a separate patch, so that it's easier to see what has been added/changed. This patch also adds a new section to the chapter about FE/BE protocol, documenting the protocol used by walsender/walreceivxer. Bump catalog version because of two new functions, pg_last_xlog_receive_location() and pg_last_xlog_replay_location(), for monitoring the progress of replication. Fujii Masao, with additional hacking by me
2010-01-15 10:19:10 +01:00
*/
Merge wal_level "archive" and "hot_standby" into new name "replica" The distinction between "archive" and "hot_standby" existed only because at the time "hot_standby" was added, there was some uncertainty about stability. This is now a long time ago. We would like to move forward with simplifying the replication configuration, but this distinction is in the way, because a primary server cannot tell (without asking a standby or predicting the future) which one of these would be the appropriate level. Pick a new name for the combined setting to make it clearer that it covers all (non-logical) backup and replication uses. The old values are still accepted but are converted internally. Reviewed-by: Michael Paquier <michael.paquier@gmail.com> Reviewed-by: David Steele <david@pgmasters.net>
2016-03-01 02:01:54 +01:00
#define XLogIsNeeded() (wal_level >= WAL_LEVEL_REPLICA)
Introduce Streaming Replication. This includes two new kinds of postmaster processes, walsenders and walreceiver. Walreceiver is responsible for connecting to the primary server and streaming WAL to disk, while walsender runs in the primary server and streams WAL from disk to the client. Documentation still needs work, but the basics are there. We will probably pull the replication section to a new chapter later on, as well as the sections describing file-based replication. But let's do that as a separate patch, so that it's easier to see what has been added/changed. This patch also adds a new section to the chapter about FE/BE protocol, documenting the protocol used by walsender/walreceivxer. Bump catalog version because of two new functions, pg_last_xlog_receive_location() and pg_last_xlog_replay_location(), for monitoring the progress of replication. Fujii Masao, with additional hacking by me
2010-01-15 10:19:10 +01:00
Add GUC to enable WAL-logging of hint bits, even with checksums disabled. WAL records of hint bit updates is useful to tools that want to examine which pages have been modified. In particular, this is required to make the pg_rewind tool safe (without checksums). This can also be used to test how much extra WAL-logging would occur if you enabled checksums, without actually enabling them (which you can't currently do without re-initdb'ing). Sawada Masahiko, docs by Samrat Revagade. Reviewed by Dilip Kumar, with further changes by me.
2013-12-13 15:26:14 +01:00
/*
* Is a full-page image needed for hint bit updates?
*
* Normally, we don't WAL-log hint bit updates, but if checksums are enabled,
* we have to protect them against torn page writes. When you only set
* individual bits on a page, it's still consistent no matter what combination
* of the bits make it to disk, but the checksum wouldn't match. Also WAL-log
Rename wal_log_hintbits to wal_log_hints, per discussion on pgsql-hackers. Sawada Masahiko
2013-12-20 19:33:16 +01:00
* them if forced by wal_log_hints=on.
Add GUC to enable WAL-logging of hint bits, even with checksums disabled. WAL records of hint bit updates is useful to tools that want to examine which pages have been modified. In particular, this is required to make the pg_rewind tool safe (without checksums). This can also be used to test how much extra WAL-logging would occur if you enabled checksums, without actually enabling them (which you can't currently do without re-initdb'ing). Sawada Masahiko, docs by Samrat Revagade. Reviewed by Dilip Kumar, with further changes by me.
2013-12-13 15:26:14 +01:00
*/
Revert "Allow on-line enabling and disabling of data checksums" This reverts the backend sides of commit 1fde38beaa0c3e66c340efc7cc0dc272d6254bb0. I have, at least for now, left the pg_verify_checksums tool in place, as this tool can be very valuable without the rest of the patch as well, and since it's a read-only tool that only runs when the cluster is down it should be a lot safer.
2018-04-09 19:02:42 +02:00
#define XLogHintBitIsNeeded() (DataChecksumsEnabled() || wal_log_hints)
Add GUC to enable WAL-logging of hint bits, even with checksums disabled. WAL records of hint bit updates is useful to tools that want to examine which pages have been modified. In particular, this is required to make the pg_rewind tool safe (without checksums). This can also be used to test how much extra WAL-logging would occur if you enabled checksums, without actually enabling them (which you can't currently do without re-initdb'ing). Sawada Masahiko, docs by Samrat Revagade. Reviewed by Dilip Kumar, with further changes by me.
2013-12-13 15:26:14 +01:00
Add new wal_level, logical, sufficient for logical decoding. When wal_level=logical, we'll log columns from the old tuple as configured by the REPLICA IDENTITY facility added in commit 07cacba983ef79be4a84fcd0e0ca3b5fcb85dd65. This makes it possible a properly-configured logical replication solution to correctly follow table updates even if they change the chosen key columns, or, with REPLICA IDENTITY FULL, even if the table has no key at all. Note that updates which do not modify the replica identity column won't log anything extra, making the choice of a good key (i.e. one that will rarely be changed) important to performance when wal_level=logical is configured. Each insert, update, or delete to a catalog table will also log the CMIN and/or CMAX values of stamped by the current transaction. This is necessary because logical decoding will require access to historical snapshots of the catalog in order to decode some data types, and the CMIN/CMAX values that we may need in order to judge row visibility may have been overwritten by the time we need them. Andres Freund, reviewed in various versions by myself, Heikki Linnakangas, KONDO Mitsumasa, and many others.
2013-12-11 00:33:45 +01:00
/* Do we need to WAL-log information required only for Hot Standby and logical replication? */
Merge wal_level "archive" and "hot_standby" into new name "replica" The distinction between "archive" and "hot_standby" existed only because at the time "hot_standby" was added, there was some uncertainty about stability. This is now a long time ago. We would like to move forward with simplifying the replication configuration, but this distinction is in the way, because a primary server cannot tell (without asking a standby or predicting the future) which one of these would be the appropriate level. Pick a new name for the combined setting to make it clearer that it covers all (non-logical) backup and replication uses. The old values are still accepted but are converted internally. Reviewed-by: Michael Paquier <michael.paquier@gmail.com> Reviewed-by: David Steele <david@pgmasters.net>
2016-03-01 02:01:54 +01:00
#define XLogStandbyInfoActive() (wal_level >= WAL_LEVEL_REPLICA)
Change a few remaining calls of XLogArchivingActive() to use XLogIsNeeded() instead, to determine if an otherwise non-logged operation needs to be logged in WAL for standby servers. Fujii Masao
2010-01-28 08:31:42 +01:00
Add new wal_level, logical, sufficient for logical decoding. When wal_level=logical, we'll log columns from the old tuple as configured by the REPLICA IDENTITY facility added in commit 07cacba983ef79be4a84fcd0e0ca3b5fcb85dd65. This makes it possible a properly-configured logical replication solution to correctly follow table updates even if they change the chosen key columns, or, with REPLICA IDENTITY FULL, even if the table has no key at all. Note that updates which do not modify the replica identity column won't log anything extra, making the choice of a good key (i.e. one that will rarely be changed) important to performance when wal_level=logical is configured. Each insert, update, or delete to a catalog table will also log the CMIN and/or CMAX values of stamped by the current transaction. This is necessary because logical decoding will require access to historical snapshots of the catalog in order to decode some data types, and the CMIN/CMAX values that we may need in order to judge row visibility may have been overwritten by the time we need them. Andres Freund, reviewed in various versions by myself, Heikki Linnakangas, KONDO Mitsumasa, and many others.
2013-12-11 00:33:45 +01:00
/* Do we need to WAL-log information required only for logical replication? */
#define XLogLogicalInfoActive() (wal_level >= WAL_LEVEL_LOGICAL)
Make the 'wal_debug' GUC variable a boolean (rather than an integer), and hide it behind #ifdef WAL_DEBUG blocks.
2004-01-06 18:26:23 +01:00
#ifdef WAL_DEBUG
Pgindent run for 8.0.
2004-08-29 07:07:03 +02:00
extern bool XLOG_DEBUG;
Make the 'wal_debug' GUC variable a boolean (rather than an integer), and hide it behind #ifdef WAL_DEBUG blocks.
2004-01-06 18:26:23 +01:00
#endif
Support syncing WAL log to disk using either fsync(), fdatasync(), O_SYNC, or O_DSYNC (as available on a given platform). Add GUC parameter to control sync method. Also, add defense to XLogWrite to prevent it from going nuts if passed a target write position that's past the end of the buffers so far filled by XLogInsert.
2001-03-16 06:44:33 +01:00
Improve logging of checkpoints. Patch by Greg Smith, worked over by Heikki and a little bit by me.
2007-06-30 21:12:02 +02:00
/*
* OR-able request flag bits for checkpoints. The "cause" bits are used only
* for logging purposes. Note: the flags must be defined so that it's
* sensible to OR together request flags arising from different requestors.
*/
/* These directly affect the behavior of CreateCheckPoint and subsidiaries */
pgindent run for 8.3.
2007-11-15 22:14:46 +01:00
#define CHECKPOINT_IS_SHUTDOWN 0x0001 /* Checkpoint is for shutdown */
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
#define CHECKPOINT_END_OF_RECOVERY 0x0002 /* Like shutdown checkpoint, but
* issued at end of WAL recovery */
Cleanup and code review for the patch that made bgwriter active during archive recovery. Invent a separate state variable and inquiry function for XLogInsertAllowed() to clarify some tests and make the management of writing the end-of-recovery checkpoint less klugy. Fix several places that were incorrectly testing InRecovery when they should be looking at RecoveryInProgress or XLogInsertAllowed (because they will now be executed in the bgwriter not startup process). Clarify handling of bad LSNs passed to XLogFlush during recovery. Use a spinlock for setting/testing SharedRecoveryInProgress. Improve quite a lot of comments. Heikki and Tom
2009-06-26 22:29:04 +02:00
#define CHECKPOINT_IMMEDIATE 0x0004 /* Do it without delays */
#define CHECKPOINT_FORCE 0x0008 /* Force even if no activity */
Renumber CHECKPOINT_* flags. Commit 7dbb6069382 added a new CHECKPOINT_FLUSH_ALL flag. As that commit needed to be backpatched I didn't change the numeric values of the existing flags as that could lead to nastly problems if any external code issued checkpoints. That's not a concern on master, so renumber them there. Also add a comment about CHECKPOINT_FLUSH_ALL above CreateCheckPoint().
2014-10-21 00:20:08 +02:00
#define CHECKPOINT_FLUSH_ALL 0x0010 /* Flush all pages, including those
* belonging to unlogged tables */
Improve logging of checkpoints. Patch by Greg Smith, worked over by Heikki and a little bit by me.
2007-06-30 21:12:02 +02:00
/* These are important to RequestCheckpoint */
Renumber CHECKPOINT_* flags. Commit 7dbb6069382 added a new CHECKPOINT_FLUSH_ALL flag. As that commit needed to be backpatched I didn't change the numeric values of the existing flags as that could lead to nastly problems if any external code issued checkpoints. That's not a concern on master, so renumber them there. Also add a comment about CHECKPOINT_FLUSH_ALL above CreateCheckPoint().
2014-10-21 00:20:08 +02:00
#define CHECKPOINT_WAIT 0x0020 /* Wait for completion */
Make checkpoint requests more robust. Commit 6f6a6d8b1 introduced a delay of up to 2 seconds if we're trying to request a checkpoint but the checkpointer hasn't started yet (or, much less likely, our kill() call fails). However buildfarm experience shows that that's not quite enough for slow or heavily-loaded machines. There's no good reason to assume that the checkpointer won't start eventually, so we may as well make the timeout much longer, say 60 sec. However, if the caller didn't say CHECKPOINT_WAIT, it seems like a bad idea to be waiting at all, much less for as long as 60 sec. We can remove the need for that, and make this whole thing more robust, by adjusting the code so that the existence of a pending checkpoint request is clear from the contents of shared memory, and making sure that the checkpointer process will notice it at startup even if it did not get a signal. In this way there's no need for a non-CHECKPOINT_WAIT call to wait at all; if it can't send the signal, it can nonetheless assume that the checkpointer will eventually service the request. A potential downside of this change is that "kill -INT" on the checkpointer process is no longer enough to trigger a checkpoint, should anyone be relying on something so hacky. But there's no obvious reason to do it like that rather than issuing a plain old CHECKPOINT command, so we'll assume that nobody is. There doesn't seem to be a way to preserve this undocumented quasi-feature without introducing race conditions. Since a principal reason for messing with this is to prevent intermittent buildfarm failures, back-patch to all supported branches. Discussion: https://postgr.es/m/27830.1552752475@sss.pgh.pa.us
2019-03-19 17:49:27 +01:00
#define CHECKPOINT_REQUESTED 0x0040 /* Checkpoint request has been made */
Improve logging of checkpoints. Patch by Greg Smith, worked over by Heikki and a little bit by me.
2007-06-30 21:12:02 +02:00
/* These indicate the cause of a checkpoint request */
Make checkpoint requests more robust. Commit 6f6a6d8b1 introduced a delay of up to 2 seconds if we're trying to request a checkpoint but the checkpointer hasn't started yet (or, much less likely, our kill() call fails). However buildfarm experience shows that that's not quite enough for slow or heavily-loaded machines. There's no good reason to assume that the checkpointer won't start eventually, so we may as well make the timeout much longer, say 60 sec. However, if the caller didn't say CHECKPOINT_WAIT, it seems like a bad idea to be waiting at all, much less for as long as 60 sec. We can remove the need for that, and make this whole thing more robust, by adjusting the code so that the existence of a pending checkpoint request is clear from the contents of shared memory, and making sure that the checkpointer process will notice it at startup even if it did not get a signal. In this way there's no need for a non-CHECKPOINT_WAIT call to wait at all; if it can't send the signal, it can nonetheless assume that the checkpointer will eventually service the request. A potential downside of this change is that "kill -INT" on the checkpointer process is no longer enough to trigger a checkpoint, should anyone be relying on something so hacky. But there's no obvious reason to do it like that rather than issuing a plain old CHECKPOINT command, so we'll assume that nobody is. There doesn't seem to be a way to preserve this undocumented quasi-feature without introducing race conditions. Since a principal reason for messing with this is to prevent intermittent buildfarm failures, back-patch to all supported branches. Discussion: https://postgr.es/m/27830.1552752475@sss.pgh.pa.us
2019-03-19 17:49:27 +01:00
#define CHECKPOINT_CAUSE_XLOG 0x0080 /* XLOG consumption */
#define CHECKPOINT_CAUSE_TIME 0x0100 /* Elapsed time */
Improve logging of checkpoints. Patch by Greg Smith, worked over by Heikki and a little bit by me.
2007-06-30 21:12:02 +02:00
Skip checkpoints, archiving on idle systems. Some background activity (like checkpoints, archive timeout, standby snapshots) is not supposed to happen on an idle system. Unfortunately so far it was not easy to determine when a system is idle, which defeated some of the attempts to avoid redundant activity on an idle system. To make that easier, allow to make individual WAL insertions as not being "important". By checking whether any important activity happened since the last time an activity was performed, it now is easy to check whether some action needs to be repeated. Use the new facility for checkpoints, archive timeout and standby snapshots. The lack of a facility causes some issues in older releases, but in my opinion the consequences (superflous checkpoints / archived segments) aren't grave enough to warrant backpatching. Author: Michael Paquier, editorialized by Andres Freund Reviewed-By: Andres Freund, David Steele, Amit Kapila, Kyotaro HORIGUCHI Bug: #13685 Discussion: https://www.postgresql.org/message-id/20151016203031.3019.72930@wrigleys.postgresql.org https://www.postgresql.org/message-id/CAB7nPqQcPqxEM3S735Bd2RzApNqSNJVietAC=6kfkYv_45dKwA@mail.gmail.com Backpatch: -
2016-12-22 20:31:50 +01:00
/*
* Flag bits for the record being inserted, set using XLogSetRecordFlags().
*/
#define XLOG_INCLUDE_ORIGIN 0x01 /* include the replication origin */
#define XLOG_MARK_UNIMPORTANT 0x02 /* record not important for durability */
Improve logging of checkpoints. Patch by Greg Smith, worked over by Heikki and a little bit by me.
2007-06-30 21:12:02 +02:00
/* Checkpoint statistics */
typedef struct CheckpointStatsData
{
pgindent run for 8.3.
2007-11-15 22:14:46 +01:00
TimestampTz ckpt_start_t; /* start of checkpoint */
TimestampTz ckpt_write_t; /* start of flushing buffers */
TimestampTz ckpt_sync_t; /* start of fsyncs */
Improve logging of checkpoints. Patch by Greg Smith, worked over by Heikki and a little bit by me.
2007-06-30 21:12:02 +02:00
TimestampTz ckpt_sync_end_t; /* end of fsyncs */
pgindent run for 8.3.
2007-11-15 22:14:46 +01:00
TimestampTz ckpt_end_t; /* end of checkpoint */
Improve logging of checkpoints. Patch by Greg Smith, worked over by Heikki and a little bit by me.
2007-06-30 21:12:02 +02:00
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
int ckpt_bufs_written; /* # of buffers written */
Improve logging of checkpoints. Patch by Greg Smith, worked over by Heikki and a little bit by me.
2007-06-30 21:12:02 +02:00
int ckpt_segs_added; /* # of new xlog segments created */
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
int ckpt_segs_removed; /* # of xlog segments deleted */
int ckpt_segs_recycled; /* # of xlog segments recycled */
Instrument checkpoint sync calls. Greg Smith, reviewed by Jeff Janes
2010-12-14 15:25:25 +01:00
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
int ckpt_sync_rels; /* # of relations synced */
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
uint64 ckpt_longest_sync; /* Longest sync for one relation */
uint64 ckpt_agg_sync_time; /* The sum of all the individual sync
* times, which is not necessarily the
* same as the total elapsed time for the
* entire sync phase. */
Re-run pgindent with updated list of typedefs. (Updated README should avoid this problem in the future.)
2007-11-15 23:25:18 +01:00
} CheckpointStatsData;
Improve logging of checkpoints. Patch by Greg Smith, worked over by Heikki and a little bit by me.
2007-06-30 21:12:02 +02:00
extern CheckpointStatsData CheckpointStats;
Implement "distributed" checkpoints in which the checkpoint I/O is spread over a fairly long period of time, rather than being spat out in a burst. This happens only for background checkpoints carried out by the bgwriter; other cases, such as a shutdown checkpoint, are still done at full speed. Remove the "all buffers" scan in the bgwriter, and associated stats infrastructure, since this seems no longer very useful when the checkpoint itself is properly throttled. Original patch by Itagaki Takahiro, reworked by Heikki Linnakangas, and some minor API editorialization by me.
2007-06-28 02:02:40 +02:00
Revamp the WAL record format. Each WAL record now carries information about the modified relation and block(s) in a standardized format. That makes it easier to write tools that need that information, like pg_rewind, prefetching the blocks to speed up recovery, etc. There's a whole new API for building WAL records, replacing the XLogRecData chains used previously. The new API consists of XLogRegister* functions, which are called for each buffer and chunk of data that is added to the record. The new API also gives more control over when a full-page image is written, by passing flags to the XLogRegisterBuffer function. This also simplifies the XLogReadBufferForRedo() calls. The function can dig the relation and block number from the WAL record, so they no longer need to be passed as arguments. For the convenience of redo routines, XLogReader now disects each WAL record after reading it, copying the main data part and the per-block data into MAXALIGNed buffers. The data chunks are not aligned within the WAL record, but the redo routines can assume that the pointers returned by XLogRecGet* functions are. Redo routines are now passed the XLogReaderState, which contains the record in the already-disected format, instead of the plain XLogRecord. The new record format also makes the fixed size XLogRecord header smaller, by removing the xl_len field. The length of the "main data" portion is now stored at the end of the WAL record, and there's a separate header after XLogRecord for it. The alignment padding at the end of XLogRecord is also removed. This compansates for the fact that the new format would otherwise be more bulky than the old format. Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera, Fujii Masao.
2014-11-20 16:56:26 +01:00
struct XLogRecData;
Skip checkpoints, archiving on idle systems. Some background activity (like checkpoints, archive timeout, standby snapshots) is not supposed to happen on an idle system. Unfortunately so far it was not easy to determine when a system is idle, which defeated some of the attempts to avoid redundant activity on an idle system. To make that easier, allow to make individual WAL insertions as not being "important". By checking whether any important activity happened since the last time an activity was performed, it now is easy to check whether some action needs to be repeated. Use the new facility for checkpoints, archive timeout and standby snapshots. The lack of a facility causes some issues in older releases, but in my opinion the consequences (superflous checkpoints / archived segments) aren't grave enough to warrant backpatching. Author: Michael Paquier, editorialized by Andres Freund Reviewed-By: Andres Freund, David Steele, Amit Kapila, Kyotaro HORIGUCHI Bug: #13685 Discussion: https://www.postgresql.org/message-id/20151016203031.3019.72930@wrigleys.postgresql.org https://www.postgresql.org/message-id/CAB7nPqQcPqxEM3S735Bd2RzApNqSNJVietAC=6kfkYv_45dKwA@mail.gmail.com Backpatch: -
2016-12-22 20:31:50 +01:00
extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata,
Phase 2 pgindent run for v12. Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22 19:04:48 +02:00
XLogRecPtr fpw_lsn,
uint8 flags);
Ye-old pgindent run. Same 4-space tabs.
2000-04-12 19:17:23 +02:00
extern void XLogFlush(XLogRecPtr RecPtr);
Reduce idle power consumption of walwriter and checkpointer processes. This patch modifies the walwriter process so that, when it has not found anything useful to do for many consecutive wakeup cycles, it extends its sleep time to reduce the server's idle power consumption. It reverts to normal as soon as it's done any successful flushes. It's still true that during any async commit, backends check for completed, unflushed pages of WAL and signal the walwriter if there are any; so that in practice the walwriter can get awakened and returned to normal operation sooner than the sleep time might suggest. Also, improve the checkpointer so that it uses a latch and a computed delay time to not wake up at all except when it has something to do, replacing a previous hardcoded 0.5 sec wakeup cycle. This also is primarily useful for reducing the server's power consumption when idle. In passing, get rid of the dedicated latch for signaling the walwriter in favor of using its procLatch, since that comports better with possible generic signal handlers using that latch. Also, fix a pre-existing bug with failure to save/restore errno in walwriter's signal handlers. Peter Geoghegan, somewhat simplified by Tom
2012-05-09 02:03:26 +02:00
extern bool XLogBackgroundFlush(void);
Make large sequential scans and VACUUMs work in a limited-size "ring" of buffers, rather than blowing out the whole shared-buffer arena. Aside from avoiding cache spoliation, this fixes the problem that VACUUM formerly tended to cause a WAL flush for every page it modified, because we had it hacked to use only a single buffer. Those flushes will now occur only once per ring-ful. The exact ring size, and the threshold for seqscans to switch into the ring usage pattern, remain under debate; but the infrastructure seems done. The key bit of infrastructure is a new optional BufferAccessStrategy object that can be passed to ReadBuffer operations; this replaces the former StrategyHintVacuum API. This patch also changes the buffer usage-count methodology a bit: we now advance usage_count when first pinning a buffer, rather than when last unpinning it. To preserve the behavior that a buffer's lifetime starts to decrease when it's released, the clock sweep code is modified to not decrement usage_count of pinned buffers. Work not done in this commit: teach GiST and GIN indexes to use the vacuum BufferAccessStrategy for vacuum-driven fetches. Original patch by Simon, reworked by Heikki and again by Tom.
2007-05-30 22:12:03 +02:00
extern bool XLogNeedsFlush(XLogRecPtr RecPtr);
pgindent run for release 9.3 This is the first run of the Perl-based pgindent script. Also update pgindent instructions.
2013-05-29 22:58:43 +02:00
extern int XLogFileInit(XLogSegNo segno, bool *use_existent, bool use_lock);
Don't waste the last segment of each 4GB logical log file. The comments claimed that wasting the last segment made it easier to do calculations with XLogRecPtrs, because you don't have problems representing last-byte-position-plus-1 that way. In my experience, however, it only made things more complicated, because the there was two ways to represent the boundary at the beginning of a logical log file: logid = n+1 and xrecoff = 0, or as xlogid = n and xrecoff = 4GB - XLOG_SEG_SIZE. Some functions were picky about which representation was used. Also, use a 64-bit segment number instead of the log/seg combination, to point to a certain WAL segment. We assume that all platforms have a working 64-bit integer type nowadays. This is an incompatible change in WAL format, so bumping WAL version number.
2012-06-24 17:06:38 +02:00
extern int XLogFileOpen(XLogSegNo segno);
Introduce Streaming Replication. This includes two new kinds of postmaster processes, walsenders and walreceiver. Walreceiver is responsible for connecting to the primary server and streaming WAL to disk, while walsender runs in the primary server and streams WAL from disk to the client. Documentation still needs work, but the basics are there. We will probably pull the replication section to a new chapter later on, as well as the sections describing file-based replication. But let's do that as a separate patch, so that it's easier to see what has been added/changed. This patch also adds a new section to the chapter about FE/BE protocol, documenting the protocol used by walsender/walreceivxer. Bump catalog version because of two new functions, pg_last_xlog_receive_location() and pg_last_xlog_replay_location(), for monitoring the progress of replication. Fujii Masao, with additional hacking by me
2010-01-15 10:19:10 +01:00
Tolerate timeline switches while "pg_basebackup -X fetch" is running. If you take a base backup from a standby server with "pg_basebackup -X fetch", and the timeline switches while the backup is being taken, the backup used to fail with an error "requested WAL segment %s has already been removed". This is because the server-side code that sends over the required WAL files would not construct the WAL filename with the correct timeline after a switch. Fix that by using readdir() to scan pg_xlog for all the WAL segments in the range, regardless of timeline. Also, include all timeline history files in the backup, if taken with "-X fetch". That fixes another related bug: If a timeline switch happened just before the backup was initiated in a standby, the WAL segment containing the initial checkpoint record contains WAL from the older timeline too. Recovery will not accept that without a timeline history file that lists the older timeline. Backpatch to 9.2. Versions prior to that were not affected as you could not take a base backup from a standby before 9.2.
2013-01-03 18:51:00 +01:00
extern void CheckXLogRemoved(XLogSegNo segno, TimeLineID tli);
Introduce logical decoding. This feature, building on previous commits, allows the write-ahead log stream to be decoded into a series of logical changes; that is, inserts, updates, and deletes and the transactions which contain them. It is capable of handling decoding even across changes to the schema of the effected tables. The output format is controlled by a so-called "output plugin"; an example is included. To make use of this in a real replication system, the output plugin will need to be modified to produce output in the format appropriate to that system, and to perform filtering. Currently, information can be extracted from the logical decoding system only via SQL; future commits will add the ability to stream changes via walsender. Andres Freund, with review and other contributions from many other people, including Álvaro Herrera, Abhijit Menon-Sen, Peter Gheogegan, Kevin Grittner, Robert Haas, Heikki Linnakangas, Fujii Masao, Abhijit Menon-Sen, Michael Paquier, Simon Riggs, Craig Ringer, and Steve Singer.
2014-03-03 22:32:18 +01:00
extern XLogSegNo XLogGetLastRemovedSegno(void);
Rename asyncCommitLSN to asyncXactLSN to reflect changed role in 9.0. Transaction aborts now record their LSN to avoid corner case behaviour in SR/HS, hence change of name of variables and functions. As pointed out by Fujii Masao. Cosmetic changes only.
2010-07-30 00:27:27 +02:00
extern void XLogSetAsyncXactLSN(XLogRecPtr record);
Introduce replication slots. Replication slots are a crash-safe data structure which can be created on either a master or a standby to prevent premature removal of write-ahead log segments needed by a standby, as well as (with hot_standby_feedback=on) pruning of tuples whose removal would cause replication conflicts. Slots have some advantages over existing techniques, as explained in the documentation. In a few places, we refer to the type of replication slots introduced by this patch as "physical" slots, because forthcoming patches for logical decoding will also have slots, but with somewhat different properties. Andres Freund and Robert Haas
2014-02-01 04:45:17 +01:00
extern void XLogSetReplicationSlotMinimumLSN(XLogRecPtr lsn);
Support an optional asynchronous commit mode, in which we don't flush WAL before reporting a transaction committed. Data consistency is still guaranteed (unlike setting fsync = off), but a crash may lose the effects of the last few transactions. Patch by Simon, some editorialization by Tom.
2007-08-02 00:45:09 +02:00
Revamp the WAL record format. Each WAL record now carries information about the modified relation and block(s) in a standardized format. That makes it easier to write tools that need that information, like pg_rewind, prefetching the blocks to speed up recovery, etc. There's a whole new API for building WAL records, replacing the XLogRecData chains used previously. The new API consists of XLogRegister* functions, which are called for each buffer and chunk of data that is added to the record. The new API also gives more control over when a full-page image is written, by passing flags to the XLogRegisterBuffer function. This also simplifies the XLogReadBufferForRedo() calls. The function can dig the relation and block number from the WAL record, so they no longer need to be passed as arguments. For the convenience of redo routines, XLogReader now disects each WAL record after reading it, copying the main data part and the per-block data into MAXALIGNed buffers. The data chunks are not aligned within the WAL record, but the redo routines can assume that the pointers returned by XLogRecGet* functions are. Redo routines are now passed the XLogReaderState, which contains the record in the already-disected format, instead of the plain XLogRecord. The new record format also makes the fixed size XLogRecord header smaller, by removing the xl_len field. The length of the "main data" portion is now stored at the end of the WAL record, and there's a separate header after XLogRecord for it. The alignment padding at the end of XLogRecord is also removed. This compansates for the fact that the new format would otherwise be more bulky than the old format. Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera, Fujii Masao.
2014-11-20 16:56:26 +01:00
extern void xlog_redo(XLogReaderState *record);
extern void xlog_desc(StringInfo buf, XLogReaderState *record);
Add rmgr callback to name xlog record types for display purposes. This is primarily useful for the upcoming pg_xlogdump --stats feature, but also allows to remove some duplicated code in the rmgr_desc routines. Due to the separation and harmonization, the output of dipsplayed records changes somewhat. But since this isn't enduser oriented content that's ok. It's potentially desirable to further change pg_xlogdump's display of records. It previously wasn't possible to show the record type separately from the description forcing it to be in the last column. But that's better done in a separate commit. Author: Abhijit Menon-Sen, slightly editorialized by me Reviewed-By: Álvaro Herrera, Andres Freund, and Heikki Linnakangas Discussion: 20140604104716.GA3989@toroid.org
2014-09-19 15:17:12 +02:00
extern const char *xlog_identify(uint8 info);
Put external declarations into header files.
2000-11-21 22:16:06 +01:00
Don't waste the last segment of each 4GB logical log file. The comments claimed that wasting the last segment made it easier to do calculations with XLogRecPtrs, because you don't have problems representing last-byte-position-plus-1 that way. In my experience, however, it only made things more complicated, because the there was two ways to represent the boundary at the beginning of a logical log file: logid = n+1 and xrecoff = 0, or as xlogid = n and xrecoff = 4GB - XLOG_SEG_SIZE. Some functions were picky about which representation was used. Also, use a 64-bit segment number instead of the log/seg combination, to point to a certain WAL segment. We assume that all platforms have a working 64-bit integer type nowadays. This is an incompatible change in WAL format, so bumping WAL version number.
2012-06-24 17:06:38 +02:00
extern void issue_xlog_fsync(int fd, XLogSegNo segno);
Introduce Streaming Replication. This includes two new kinds of postmaster processes, walsenders and walreceiver. Walreceiver is responsible for connecting to the primary server and streaming WAL to disk, while walsender runs in the primary server and streams WAL from disk to the client. Documentation still needs work, but the basics are there. We will probably pull the replication section to a new chapter later on, as well as the sections describing file-based replication. But let's do that as a separate patch, so that it's easier to see what has been added/changed. This patch also adds a new section to the chapter about FE/BE protocol, documenting the protocol used by walsender/walreceivxer. Bump catalog version because of two new functions, pg_last_xlog_receive_location() and pg_last_xlog_replay_location(), for monitoring the progress of replication. Fujii Masao, with additional hacking by me
2010-01-15 10:19:10 +01:00
Start background writer during archive recovery. Background writer now performs its usual buffer cleaning duties during archive recovery, and it's responsible for performing restartpoints. This requires some changes in postmaster. When the startup process has done all the initialization and is ready to start WAL redo, it signals the postmaster to launch the background writer. The postmaster is signaled again when the point in recovery is reached where we know that the database is in consistent state. Postmaster isn't interested in that at the moment, but that's the point where we could let other backends in to perform read-only queries. The postmaster is signaled third time when the recovery has ended, so that postmaster knows that it's safe to start accepting connections. The startup process now traps SIGTERM, and performs a "clean" shutdown. If you do a fast shutdown during recovery, a shutdown restartpoint is performed, like a shutdown checkpoint, and postmaster kills the processes cleanly. You still have to continue the recovery at next startup, though. Currently, the background writer is only launched during archive recovery. We could launch it during crash recovery as well, but it seems better to keep that codepath as simple as possible, for the sake of robustness. And it couldn't do any restartpoints during crash recovery anyway, so it wouldn't be that useful. log_restartpoints is gone. Use log_checkpoints instead. This is yet to be documented. This whole operation is a pre-requisite for Hot Standby, but has some value of its own whether the hot standby patch makes 8.4 or not. Simon Riggs, with lots of modifications by me.
2009-02-18 16:58:41 +01:00
extern bool RecoveryInProgress(void);
Hot Standby feedback for avoidance of cleanup conflicts on standby. Standby optionally sends back information about oldestXmin of queries which is then checked and applied to the WALSender's proc->xmin. GetOldestXmin() is modified slightly to agree with GetSnapshotData(), so that all backends on primary include WALSender within their snapshots. Note this does nothing to change the snapshot xmin on either master or standby. Feedback piggybacks on the standby reply message. vacuum_defer_cleanup_age is no longer used on standby, though parameter still exists on primary, since some use cases still exist. Simon Riggs, review comments from Fujii Masao, Heikki Linnakangas, Robert Haas
2011-02-16 20:29:37 +01:00
extern bool HotStandbyActive(void);
Fix multiple bugs in index page locking during hot-standby WAL replay. In ordinary operation, VACUUM must be careful to take a cleanup lock on each leaf page of a btree index; this ensures that no indexscans could still be "in flight" to heap tuples due to be deleted. (Because of possible index-tuple motion due to concurrent page splits, it's not enough to lock only the pages we're deleting index tuples from.) In Hot Standby, the WAL replay process must likewise lock every leaf page. There were several bugs in the code for that: * The replay scan might come across unused, all-zero pages in the index. While btree_xlog_vacuum itself did the right thing (ie, nothing) with such pages, xlogutils.c supposed that such pages must be corrupt and would throw an error. This accounts for various reports of replication failures with "PANIC: WAL contains references to invalid pages". To fix, add a ReadBufferMode value that instructs XLogReadBufferExtended not to complain when we're doing this. * btree_xlog_vacuum performed the extra locking if standbyState == STANDBY_SNAPSHOT_READY, but that's not the correct test: we won't open up for hot standby queries until the database has reached consistency, and we don't want to do the extra locking till then either, for fear of reading corrupted pages (which bufmgr.c would complain about). Fix by exporting a new function from xlog.c that will report whether we're actually in hot standby replay mode. * To ensure full coverage of the index in the replay scan, btvacuumscan would emit a dummy WAL record for the last page of the index, if no vacuuming work had been done on that page. However, if the last page of the index is all-zero, that would result in corruption of said page, since the functions called on it weren't prepared to handle that case. There's no need to lock any such pages, so change the logic to target the last normal leaf page instead. The first two of these bugs were diagnosed by Andres Freund, the other one by me. Fixes based on ideas from Heikki Linnakangas and myself. This has been wrong since Hot Standby was introduced, so back-patch to 9.0.
2014-01-14 23:34:47 +01:00
extern bool HotStandbyActiveInReplay(void);
Cleanup and code review for the patch that made bgwriter active during archive recovery. Invent a separate state variable and inquiry function for XLogInsertAllowed() to clarify some tests and make the management of writing the end-of-recovery checkpoint less klugy. Fix several places that were incorrectly testing InRecovery when they should be looking at RecoveryInProgress or XLogInsertAllowed (because they will now be executed in the bgwriter not startup process). Clarify handling of bad LSNs passed to XLogFlush during recovery. Use a spinlock for setting/testing SharedRecoveryInProgress. Improve quite a lot of comments. Heikki and Tom
2009-06-26 22:29:04 +02:00
extern bool XLogInsertAllowed(void);
Replace max_standby_delay with two parameters, max_standby_archive_delay and max_standby_streaming_delay, and revise the implementation to avoid assuming that timestamps found in WAL records can meaningfully be compared to clock time on the standby server. Instead, the delay limits are compared to the elapsed time since we last obtained a new WAL segment from archive or since we were last "caught up" to WAL data arriving via streaming replication. This avoids problems with clock skew between primary and standby, as well as other corner cases that the original coding would misbehave in, such as the primary server having significant idle time between transactions. Per my complaint some time ago and considerable ensuing discussion. Do some desultory editing on the hot standby documentation, too.
2010-07-03 22:43:58 +02:00
extern void GetXLogReceiptTime(TimestampTz *rtime, bool *fromStream);
Follow TLI of last replayed record, not recovery target TLI, in walsenders. Most of the time, the last replayed record comes from the recovery target timeline, but there is a corner case where it makes a difference. When the startup process scans for a new timeline, and decides to change recovery target timeline, there is a window where the recovery target TLI has already been bumped, but there are no WAL segments from the new timeline in pg_xlog yet. For example, if we have just replayed up to point 0/30002D8, on timeline 1, there is a WAL file called 000000010000000000000003 in pg_xlog that contains the WAL up to that point. When recovery switches recovery target timeline to 2, a walsender can immediately try to read WAL from 0/30002D8, from timeline 2, so it will try to open WAL file 000000020000000000000003. However, that doesn't exist yet - the startup process hasn't copied that file from the archive yet nor has the walreceiver streamed it yet, so walsender fails with error "requested WAL segment 000000020000000000000003 has already been removed". That's harmless, in that the standby will try to reconnect later and by that time the segment is already created, but error messages that should be ignored are not good. To fix that, have walsender track the TLI of the last replayed record, instead of the recovery target timeline. That way walsender will not try to read anything from timeline 2, until the WAL segment has been created and at least one record has been replayed from it. The recovery target timeline is now xlog.c's internal affair, it doesn't need to be exposed in shared memory anymore. This fixes the error reported by Thom Brown. depesz the same error message, but I'm not sure if this fixes his scenario.
2012-12-20 13:23:31 +01:00
extern XLogRecPtr GetXLogReplayRecPtr(TimeLineID *replayTLI);
Remove useless 'needlock' argument from GetXLogInsertRecPtr. It was always passed as 'true'.
2012-01-11 10:00:53 +01:00
extern XLogRecPtr GetXLogInsertRecPtr(void);
Move user functions related to WAL into xlogfuncs.c
2011-11-04 10:37:17 +01:00
extern XLogRecPtr GetXLogWriteRecPtr(void);
extern bool RecoveryIsPaused(void);
extern void SetRecoveryPause(bool recoveryPause);
extern TimestampTz GetLatestXTime(void);
Send new protocol keepalive messages to standby servers. Allows streaming replication users to calculate transfer latency and apply delay via internal functions. No external functions yet.
2011-12-31 14:30:26 +01:00
extern TimestampTz GetCurrentChunkReplayStartTime(void);
Start background writer during archive recovery. Background writer now performs its usual buffer cleaning duties during archive recovery, and it's responsible for performing restartpoints. This requires some changes in postmaster. When the startup process has done all the initialization and is ready to start WAL redo, it signals the postmaster to launch the background writer. The postmaster is signaled again when the point in recovery is reached where we know that the database is in consistent state. Postmaster isn't interested in that at the moment, but that's the point where we could let other backends in to perform read-only queries. The postmaster is signaled third time when the recovery has ended, so that postmaster knows that it's safe to start accepting connections. The startup process now traps SIGTERM, and performs a "clean" shutdown. If you do a fast shutdown during recovery, a shutdown restartpoint is performed, like a shutdown checkpoint, and postmaster kills the processes cleanly. You still have to continue the recovery at next startup, though. Currently, the background writer is only launched during archive recovery. We could launch it during crash recovery as well, but it seems better to keep that codepath as simple as possible, for the sake of robustness. And it couldn't do any restartpoints during crash recovery anyway, so it wouldn't be that useful. log_restartpoints is gone. Use log_checkpoints instead. This is yet to be documented. This whole operation is a pre-requisite for Hot Standby, but has some value of its own whether the hot standby patch makes 8.4 or not. Simon Riggs, with lots of modifications by me.
2009-02-18 16:58:41 +01:00
Put external declarations into header files.
2000-11-21 22:16:06 +01:00
extern void UpdateControlFile(void);
Introduce Streaming Replication. This includes two new kinds of postmaster processes, walsenders and walreceiver. Walreceiver is responsible for connecting to the primary server and streaming WAL to disk, while walsender runs in the primary server and streams WAL from disk to the client. Documentation still needs work, but the basics are there. We will probably pull the replication section to a new chapter later on, as well as the sections describing file-based replication. But let's do that as a separate patch, so that it's easier to see what has been added/changed. This patch also adds a new section to the chapter about FE/BE protocol, documenting the protocol used by walsender/walreceivxer. Bump catalog version because of two new functions, pg_last_xlog_receive_location() and pg_last_xlog_replay_location(), for monitoring the progress of replication. Fujii Masao, with additional hacking by me
2010-01-15 10:19:10 +01:00
extern uint64 GetSystemIdentifier(void);
Support SCRAM-SHA-256 authentication (RFC 5802 and 7677). This introduces a new generic SASL authentication method, similar to the GSS and SSPI methods. The server first tells the client which SASL authentication mechanism to use, and then the mechanism-specific SASL messages are exchanged in AuthenticationSASLcontinue and PasswordMessage messages. Only SCRAM-SHA-256 is supported at the moment, but this allows adding more SASL mechanisms in the future, without changing the overall protocol. Support for channel binding, aka SCRAM-SHA-256-PLUS is left for later. The SASLPrep algorithm, for pre-processing the password, is not yet implemented. That could cause trouble, if you use a password with non-ASCII characters, and a client library that does implement SASLprep. That will hopefully be added later. Authorization identities, as specified in the SCRAM-SHA-256 specification, are ignored. SET SESSION AUTHORIZATION provides more or less the same functionality, anyway. If a user doesn't exist, perform a "mock" authentication, by constructing an authentic-looking challenge on the fly. The challenge is derived from a new system-wide random value, "mock authentication nonce", which is created at initdb, and stored in the control file. We go through these motions, in order to not give away the information on whether the user exists, to unauthenticated users. Bumps PG_CONTROL_VERSION, because of the new field in control file. Patch by Michael Paquier and Heikki Linnakangas, reviewed at different stages by Robert Haas, Stephen Frost, David Steele, Aleksander Alekseev, and many others. Discussion: https://www.postgresql.org/message-id/CAB7nPqRbR3GmFYdedCAhzukfKrgBLTLtMvENOmPrVWREsZkF8g%40mail.gmail.com Discussion: https://www.postgresql.org/message-id/CAB7nPqSMXU35g%3DW9X74HVeQp0uvgJxvYOuA4A-A3M%2B0wfEBv-w%40mail.gmail.com Discussion: https://www.postgresql.org/message-id/55192AFE.6080106@iki.fi
2017-03-07 13:25:40 +01:00
extern char *GetMockAuthenticationNonce(void);
Revert "Allow on-line enabling and disabling of data checksums" This reverts the backend sides of commit 1fde38beaa0c3e66c340efc7cc0dc272d6254bb0. I have, at least for now, left the pg_verify_checksums tool in place, as this tool can be very valuable without the rest of the patch as well, and since it's a read-only tool that only runs when the cluster is down it should be a lot safer.
2018-04-09 19:02:42 +02:00
extern bool DataChecksumsEnabled(void);
Support unlogged GiST index. The reason this wasn't supported before was that GiST indexes need an increasing sequence to detect concurrent page-splits. In a regular WAL- logged GiST index, the LSN of the page-split record is used for that purpose, and in a temporary index, we can get away with a backend-local counter. Neither of those methods works for an unlogged relation. To provide such an increasing sequence of numbers, create a "fake LSN" counter that is saved and restored across shutdowns. On recovery, unlogged relations are blown away, so the counter doesn't need to survive that either. Jeevan Chalke, based on discussions with Robert Haas, Tom Lane and me.
2013-02-11 21:50:15 +01:00
extern XLogRecPtr GetFakeLSNForUnloggedRel(void);
Convert the arithmetic for shared memory size calculation from 'int' to 'Size' (that is, size_t), and install overflow detection checks in it. This allows us to remove the former arbitrary restrictions on NBuffers etc. It won't make any difference in a 32-bit machine, but in a 64-bit machine you could theoretically have terabytes of shared buffers. (How efficiently we could manage 'em remains to be seen.) Similarly, num_temp_buffers, work_mem, and maintenance_work_mem can be set above 2Gb on a 64-bit machine. Original patch from Koichi Suzuki, additional work by moi.
2005-08-21 01:26:37 +02:00
extern Size XLOGShmemSize(void);
Put external declarations into header files.
2000-11-21 22:16:06 +01:00
extern void XLOGShmemInit(void);
extern void BootStrapXLOG(void);
Fix crash restart bug introduced in 8356753c212. The bug was caused by not re-reading the control file during crash recovery restarts, which lead to an attempt to pfree() shared memory contents. The fix is to re-read the control file, which seems good anyway. It's unclear as of this moment, whether we want to keep the refactoring introduced in the commit referenced above, or come up with an alternative approach. But fixing the bug in the mean time seems like a good idea regardless. A followup commit will introduce regression test coverage for crash restarts. Reported-By: Tom Lane Discussion: https://postgr.es/m/14134.1505572349@sss.pgh.pa.us
2017-09-17 10:00:39 +02:00
extern void LocalProcessControlFile(bool reset);
Put external declarations into header files.
2000-11-21 22:16:06 +01:00
extern void StartupXLOG(void);
This patch properly sets the prototype for the on_shmem_exit and on_proc_exit functions, and adjust all other related code to use the proper types too. by Kurt Roeckx
2003-12-12 19:45:10 +01:00
extern void ShutdownXLOG(int code, Datum arg);
Get rid of the former rather baroque mechanism for propagating the values of ThisStartUpID and RedoRecPtr into new backends. It's a lot easier just to make them all grab the values out of shared memory during startup. This helps to decouple the postmaster from checkpoint execution, which I need since I'm intending to let the bgwriter do it instead, and it also fixes a bug in the Win32 port: ThisStartUpID wasn't getting propagated at all AFAICS. (Doesn't give me a lot of faith in the amount of testing that port has gotten.)
2004-05-27 19:12:57 +02:00
extern void InitXLOGAccess(void);
Implement "distributed" checkpoints in which the checkpoint I/O is spread over a fairly long period of time, rather than being spat out in a burst. This happens only for background checkpoints carried out by the bgwriter; other cases, such as a shutdown checkpoint, are still done at full speed. Remove the "all buffers" scan in the bgwriter, and associated stats infrastructure, since this seems no longer very useful when the checkpoint itself is properly throttled. Original patch by Itagaki Takahiro, reworked by Heikki Linnakangas, and some minor API editorialization by me.
2007-06-28 02:02:40 +02:00
extern void CreateCheckPoint(int flags);
Start background writer during archive recovery. Background writer now performs its usual buffer cleaning duties during archive recovery, and it's responsible for performing restartpoints. This requires some changes in postmaster. When the startup process has done all the initialization and is ready to start WAL redo, it signals the postmaster to launch the background writer. The postmaster is signaled again when the point in recovery is reached where we know that the database is in consistent state. Postmaster isn't interested in that at the moment, but that's the point where we could let other backends in to perform read-only queries. The postmaster is signaled third time when the recovery has ended, so that postmaster knows that it's safe to start accepting connections. The startup process now traps SIGTERM, and performs a "clean" shutdown. If you do a fast shutdown during recovery, a shutdown restartpoint is performed, like a shutdown checkpoint, and postmaster kills the processes cleanly. You still have to continue the recovery at next startup, though. Currently, the background writer is only launched during archive recovery. We could launch it during crash recovery as well, but it seems better to keep that codepath as simple as possible, for the sake of robustness. And it couldn't do any restartpoints during crash recovery anyway, so it wouldn't be that useful. log_restartpoints is gone. Use log_checkpoints instead. This is yet to be documented. This whole operation is a pre-requisite for Hot Standby, but has some value of its own whether the hot standby patch makes 8.4 or not. Simon Riggs, with lots of modifications by me.
2009-02-18 16:58:41 +01:00
extern bool CreateRestartPoint(int flags);
XLOG (and related) changes: * Store two past checkpoint locations, not just one, in pg_control. On startup, we fall back to the older checkpoint if the newer one is unreadable. Also, a physical copy of the newest checkpoint record is kept in pg_control for possible use in disaster recovery (ie, complete loss of pg_xlog). Also add a version number for pg_control itself. Remove archdir from pg_control; it ought to be a GUC parameter, not a special case (not that it's implemented yet anyway). * Suppress successive checkpoint records when nothing has been entered in the WAL log since the last one. This is not so much to avoid I/O as to make it actually useful to keep track of the last two checkpoints. If the things are right next to each other then there's not a lot of redundancy gained... * Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs on alternate bytes. Polynomial borrowed from ECMA DLT1 standard. * Fix XLOG record length handling so that it will work at BLCKSZ = 32k. * Change XID allocation to work more like OID allocation. (This is of dubious necessity, but I think it's a good idea anyway.) * Fix a number of minor bugs, such as off-by-one logic for XLOG file wraparound at the 4 gig mark. * Add documentation and clean up some coding infelicities; move file format declarations out to include files where planned contrib utilities can get at them. * Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also possible to force a checkpoint by sending SIGUSR1 to the postmaster (undocumented feature...) * Defend against kill -9 postmaster by storing shmem block's key and ID in postmaster.pid lockfile, and checking at startup to ensure that no processes are still connected to old shmem block (if it still exists). * Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency stop, for symmetry with postmaster and xlog utilities. Clean up signal handling in bootstrap.c so that xlog utilities launched by postmaster will react to signals better. * Standalone bootstrap now grabs lockfile in target directory, as added insurance against running it in parallel with live postmaster.
2001-03-13 02:17:06 +01:00
extern void XLogPutNextOid(Oid nextOid);
Named restore points in recovery. Users can record named points, then new recovery.conf parameter recovery_target_name allows PITR to specify named points as recovery targets. Jaime Casanova, reviewed by Euler Taveira de Oliveira, plus minor edits
2011-02-08 20:39:08 +01:00
extern XLogRecPtr XLogRestorePoint(const char *rpName);
Allow pg_basebackup from standby node with safety checking. Base backup follows recommended procedure, plus goes to great lengths to ensure that partial page writes are avoided. Jun Ishizuka and Fujii Masao, with minor modifications
2012-01-25 19:02:04 +01:00
extern void UpdateFullPageWrites(void);
Move the backup-block logic from XLogInsert to a new file, xloginsert.c. xlog.c is huge, this makes it a little bit smaller, which is nice. Functions related to putting together the WAL record are in xloginsert.c, and the lower level stuff for managing WAL buffers and such are in xlog.c. Also move the definition of XLogRecord to a separate header file. This causes churn in the #includes of all the files that write WAL records, and redo routines, but it avoids pulling in xlog.h into most places. Reviewed by Michael Paquier, Alvaro Herrera, Andres Freund and Amit Kapila.
2014-11-06 12:52:08 +01:00
extern void GetFullPageWriteInfo(XLogRecPtr *RedoRecPtr_p, bool *doPageWrites_p);
Repair two problems with WAL logging of sequence nextvalI() ops, as per recent pghackers discussion: force a new WAL record at first nextval after a checkpoint, and ensure that xlog is flushed to disk if a nextval record is the only thing emitted by a transaction.
2002-03-15 20:20:36 +01:00
extern XLogRecPtr GetRedoRecPtr(void);
Implement "distributed" checkpoints in which the checkpoint I/O is spread over a fairly long period of time, rather than being spat out in a burst. This happens only for background checkpoints carried out by the bgwriter; other cases, such as a shutdown checkpoint, are still done at full speed. Remove the "all buffers" scan in the bgwriter, and associated stats infrastructure, since this seems no longer very useful when the checkpoint itself is properly throttled. Original patch by Itagaki Takahiro, reworked by Heikki Linnakangas, and some minor API editorialization by me.
2007-06-28 02:02:40 +02:00
extern XLogRecPtr GetInsertRecPtr(void);
Don't allow walsender to send WAL data until it's been safely fsync'd on the master. Otherwise a subsequent crash could cause the master to lose WAL that has already been applied on the slave, resulting in the slave being out of sync and soon corrupt. Per recent discussion and an example from Robert Haas. Fujii Masao
2010-06-17 18:41:25 +02:00
extern XLogRecPtr GetFlushRecPtr(void);
Skip checkpoints, archiving on idle systems. Some background activity (like checkpoints, archive timeout, standby snapshots) is not supposed to happen on an idle system. Unfortunately so far it was not easy to determine when a system is idle, which defeated some of the attempts to avoid redundant activity on an idle system. To make that easier, allow to make individual WAL insertions as not being "important". By checking whether any important activity happened since the last time an activity was performed, it now is easy to check whether some action needs to be repeated. Use the new facility for checkpoints, archive timeout and standby snapshots. The lack of a facility causes some issues in older releases, but in my opinion the consequences (superflous checkpoints / archived segments) aren't grave enough to warrant backpatching. Author: Michael Paquier, editorialized by Andres Freund Reviewed-By: Andres Freund, David Steele, Amit Kapila, Kyotaro HORIGUCHI Bug: #13685 Discussion: https://www.postgresql.org/message-id/20151016203031.3019.72930@wrigleys.postgresql.org https://www.postgresql.org/message-id/CAB7nPqQcPqxEM3S735Bd2RzApNqSNJVietAC=6kfkYv_45dKwA@mail.gmail.com Backpatch: -
2016-12-22 20:31:50 +01:00
extern XLogRecPtr GetLastImportantRecPtr(void);
Remove files signaling a standby promotion request at postmaster startup This commit makes postmaster forcibly remove the files signaling a standby promotion request. Otherwise, the existence of those files can trigger a promotion too early, whether a user wants that or not. This removal of files is usually unnecessary because they can exist only during a few moments during a standby promotion. However there is a race condition: if pg_ctl promote is executed and creates the files during a promotion, the files can stay around even after the server is brought up to new master. Then, if new standby starts by using the backup taken from that master, the files can exist at the server startup and should be removed in order to avoid an unexpected promotion. Back-patch to 9.1 where promote signal file was introduced. Problem reported by Feike Steenbergen. Original patch by Michael Paquier, modified by me. Discussion: 20150528100705.4686.91426@wrigleys.postgresql.org
2015-09-09 15:51:44 +02:00
extern void RemovePromoteSignalFiles(void);
Put external declarations into header files.
2000-11-21 22:16:06 +01:00
pg_ctl promote Fujii Masao, reviewed by Robert Haas, Stephen Frost, and Magnus Hagander.
2011-02-16 03:28:48 +01:00
extern bool CheckPromoteSignal(void);
Use a latch to make startup process wake up and replay immediately when new WAL arrives via streaming replication. This reduces the latency, and also allows us to use a longer polling interval, which is good for energy efficiency. We still need to poll to check for the appearance of a trigger file, but the interval is now 5 seconds (instead of 100ms), like when waiting for a new WAL segment to appear in WAL archive.
2010-09-15 12:35:05 +02:00
extern void WakeupRecovery(void);
Fix an issue in recent walwriter hibernation patch. Users of asynchronous-commit mode expect there to be a guaranteed maximum delay before an async commit's WAL records get flushed to disk. The original version of the walwriter hibernation patch broke that. Add an extra shared-memory flag to allow async commits to kick the walwriter out of hibernation mode, without adding any noticeable overhead in cases where no action is needed.
2012-05-09 05:05:58 +02:00
extern void SetWalWriterSleeping(bool sleeping);
Start background writer during archive recovery. Background writer now performs its usual buffer cleaning duties during archive recovery, and it's responsible for performing restartpoints. This requires some changes in postmaster. When the startup process has done all the initialization and is ready to start WAL redo, it signals the postmaster to launch the background writer. The postmaster is signaled again when the point in recovery is reached where we know that the database is in consistent state. Postmaster isn't interested in that at the moment, but that's the point where we could let other backends in to perform read-only queries. The postmaster is signaled third time when the recovery has ended, so that postmaster knows that it's safe to start accepting connections. The startup process now traps SIGTERM, and performs a "clean" shutdown. If you do a fast shutdown during recovery, a shutdown restartpoint is performed, like a shutdown checkpoint, and postmaster kills the processes cleanly. You still have to continue the recovery at next startup, though. Currently, the background writer is only launched during archive recovery. We could launch it during crash recovery as well, but it seems better to keep that codepath as simple as possible, for the sake of robustness. And it couldn't do any restartpoints during crash recovery anyway, so it wouldn't be that useful. log_restartpoints is gone. Use log_checkpoints instead. This is yet to be documented. This whole operation is a pre-requisite for Hot Standby, but has some value of its own whether the hot standby patch makes 8.4 or not. Simon Riggs, with lots of modifications by me.
2009-02-18 16:58:41 +01:00
Add new replication mode synchronous_commit = 'remote_apply'. In this mode, the master waits for the transaction to be applied on the remote side, not just written to disk. That means that you can count on a transaction started on the standby to see all commits previously acknowledged by the master. To make this work, the standby sends a reply after replaying each commit record generated with synchronous_commit >= 'remote_apply'. This introduces a small inefficiency: the extra replies will be sent even by standbys that aren't the current synchronous standby. But previously-existing synchronous_commit levels make no attempt at all to optimize which replies are sent based on what the primary cares about, so this is no worse, and at least avoids any extra replies for people not using the feature at all. Thomas Munro, reviewed by Michael Paquier and by me. Some additional tweaks by me.
2016-03-30 03:16:12 +02:00
extern void XLogRequestWalReceiverReply(void);
Replace checkpoint_segments with min_wal_size and max_wal_size. Instead of having a single knob (checkpoint_segments) that both triggers checkpoints, and determines how many checkpoints to recycle, they are now separate concerns. There is still an internal variable called CheckpointSegments, which triggers checkpoints. But it no longer determines how many segments to recycle at a checkpoint. That is now auto-tuned by keeping a moving average of the distance between checkpoints (in bytes), and trying to keep that many segments in reserve. The advantage of this is that you can set max_wal_size very high, but the system won't actually consume that much space if there isn't any need for it. The min_wal_size sets a floor for that; you can effectively disable the auto-tuning behavior by setting min_wal_size equal to max_wal_size. The max_wal_size setting is now the actual target size of WAL at which a new checkpoint is triggered, instead of the distance between checkpoints. Previously, you could calculate the actual WAL usage with the formula "(2 + checkpoint_completion_target) * checkpoint_segments + 1". With this patch, you set the desired WAL usage with max_wal_size, and the system calculates the appropriate CheckpointSegments with the reverse of that formula. That's a lot more intuitive for administrators to set. Reviewed by Amit Kapila and Venkata Balaji N.
2015-02-23 17:53:02 +01:00
extern void assign_max_wal_size(int newval, void *extra);
extern void assign_checkpoint_completion_target(double newval, void *extra);
Support multiple concurrent pg_basebackup backups. With this patch, pg_basebackup doesn't write a backup_label file in the data directory, so it doesn't interfere with a pg_start/stop_backup() based backup anymore. backup_label is still included in the backup, but it is injected directly into the tar stream. Heikki Linnakangas, reviewed by Fujii Masao and Magnus Hagander.
2011-01-31 17:13:01 +01:00
/*
Fix backup canceling Assert-enabled build crashes but without asserts it works by wrong way: it may not reset forcing full page write and preventing from starting exclusive backup with the same name as cancelled. Patch replaces pair of booleans nonexclusive_backup_running/exclusive_backup_running to single enum to correctly describe backup state. Backpatch to 9.6 where bug was introduced Reported-by: David Steele Authors: Michael Paquier, David Steele Reviewed-by: Anastasia Lubennikova https://commitfest.postgresql.org/13/1068/
2017-03-24 11:53:40 +01:00
* Routines to start, stop, and get status of a base backup.
Support multiple concurrent pg_basebackup backups. With this patch, pg_basebackup doesn't write a backup_label file in the data directory, so it doesn't interfere with a pg_start/stop_backup() based backup anymore. backup_label is still included in the backup, but it is injected directly into the tar stream. Heikki Linnakangas, reviewed by Fujii Masao and Magnus Hagander.
2011-01-31 17:13:01 +01:00
*/
Fix backup canceling Assert-enabled build crashes but without asserts it works by wrong way: it may not reset forcing full page write and preventing from starting exclusive backup with the same name as cancelled. Patch replaces pair of booleans nonexclusive_backup_running/exclusive_backup_running to single enum to correctly describe backup state. Backpatch to 9.6 where bug was introduced Reported-by: David Steele Authors: Michael Paquier, David Steele Reviewed-by: Anastasia Lubennikova https://commitfest.postgresql.org/13/1068/
2017-03-24 11:53:40 +01:00
/*
* Session-level status of base backups
*
* This is used in parallel with the shared memory status to control parallel
* execution of base backup functions for a given session, be it a backend
* dedicated to replication or a normal backend connected to a database. The
* update of the session-level status happens at the same time as the shared
* memory counters to keep a consistent global and local state of the backups
* running.
*/
typedef enum SessionBackupState
{
SESSION_BACKUP_NONE,
SESSION_BACKUP_EXCLUSIVE,
SESSION_BACKUP_NON_EXCLUSIVE
} SessionBackupState;
Make pg_receivexlog and pg_basebackup -X stream work across timeline switches. This mirrors the changes done earlier to the server in standby mode. When receivelog reaches the end of a timeline, as reported by the server, it fetches the timeline history file of the next timeline, and restarts streaming from the new timeline by issuing a new START_STREAMING command. When pg_receivexlog crosses a timeline, it leaves the .partial suffix on the last segment on the old timeline. This helps you to tell apart a partial segment left in the directory because of a timeline switch, and a completed segment. If you just follow a single server, it won't make a difference, but it can be significant in more complicated scenarios where new WAL is still generated on the old timeline. This includes two small changes to the streaming replication protocol: First, when you reach the end of timeline while streaming, the server now sends the TLI of the next timeline in the server's history to the client. pg_receivexlog uses that as the next timeline, so that it doesn't need to parse the timeline history file like a standby server does. Second, when BASE_BACKUP command sends the begin and end WAL positions, it now also sends the timeline IDs corresponding the positions.
2013-01-17 19:23:00 +01:00
extern XLogRecPtr do_pg_start_backup(const char *backupidstr, bool fast,
Phase 2 pgindent run for v12. Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22 19:04:48 +02:00
TimeLineID *starttli_p, StringInfo labelfile,
List **tablespaces, StringInfo tblspcmapfile, bool infotbssize,
bool needtblspcmapfile);
Make pg_receivexlog and pg_basebackup -X stream work across timeline switches. This mirrors the changes done earlier to the server in standby mode. When receivelog reaches the end of a timeline, as reported by the server, it fetches the timeline history file of the next timeline, and restarts streaming from the new timeline by issuing a new START_STREAMING command. When pg_receivexlog crosses a timeline, it leaves the .partial suffix on the last segment on the old timeline. This helps you to tell apart a partial segment left in the directory because of a timeline switch, and a completed segment. If you just follow a single server, it won't make a difference, but it can be significant in more complicated scenarios where new WAL is still generated on the old timeline. This includes two small changes to the streaming replication protocol: First, when you reach the end of timeline while streaming, the server now sends the TLI of the next timeline in the server's history to the client. pg_receivexlog uses that as the next timeline, so that it doesn't need to parse the timeline history file like a standby server does. Second, when BASE_BACKUP command sends the begin and end WAL positions, it now also sends the timeline IDs corresponding the positions.
2013-01-17 19:23:00 +01:00
extern XLogRecPtr do_pg_stop_backup(char *labelfile, bool waitforarchive,
Phase 2 pgindent run for v12. Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22 19:04:48 +02:00
TimeLineID *stoptli_p);
Split pg_start_backup() and pg_stop_backup() into two pieces Move the actual functionality into a separate function that's easier to call internally, and change the SQL-callable function to be a wrapper calling this. Also create a pg_abort_backup() function, only callable internally, that does only the most vital parts of pg_stop_backup(), making it safe(r) to call from error handlers.
2011-01-09 21:00:28 +01:00
extern void do_pg_abort_backup(void);
Fix backup canceling Assert-enabled build crashes but without asserts it works by wrong way: it may not reset forcing full page write and preventing from starting exclusive backup with the same name as cancelled. Patch replaces pair of booleans nonexclusive_backup_running/exclusive_backup_running to single enum to correctly describe backup state. Backpatch to 9.6 where bug was introduced Reported-by: David Steele Authors: Michael Paquier, David Steele Reviewed-by: Anastasia Lubennikova https://commitfest.postgresql.org/13/1068/
2017-03-24 11:53:40 +01:00
extern SessionBackupState get_backup_status(void);
Split pg_start_backup() and pg_stop_backup() into two pieces Move the actual functionality into a separate function that's easier to call internally, and change the SQL-callable function to be a wrapper calling this. Also create a pg_abort_backup() function, only callable internally, that does only the most vital parts of pg_stop_backup(), making it safe(r) to call from error handlers.
2011-01-09 21:00:28 +01:00
Support multiple concurrent pg_basebackup backups. With this patch, pg_basebackup doesn't write a backup_label file in the data directory, so it doesn't interfere with a pg_start/stop_backup() based backup anymore. backup_label is still included in the backup, but it is injected directly into the tar stream. Heikki Linnakangas, reviewed by Fujii Masao and Magnus Hagander.
2011-01-31 17:13:01 +01:00
/* File path names (all relative to $PGDATA) */
Integrate recovery.conf into postgresql.conf recovery.conf settings are now set in postgresql.conf (or other GUC sources). Currently, all the affected settings are PGC_POSTMASTER; this could be refined in the future case by case. Recovery is now initiated by a file recovery.signal. Standby mode is initiated by a file standby.signal. The standby_mode setting is gone. If a recovery.conf file is found, an error is issued. The trigger_file setting has been renamed to promote_trigger_file as part of the move. The documentation chapter "Recovery Configuration" has been integrated into "Server Configuration". pg_basebackup -R now appends settings to postgresql.auto.conf and creates a standby.signal file. Author: Fujii Masao <masao.fujii@gmail.com> Author: Simon Riggs <simon@2ndquadrant.com> Author: Abhijit Menon-Sen <ams@2ndquadrant.com> Author: Sergei Kornilov <sk@zsrv.org> Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
2018-11-25 16:31:16 +01:00
#define RECOVERY_SIGNAL_FILE "recovery.signal"
#define STANDBY_SIGNAL_FILE "standby.signal"
Support multiple concurrent pg_basebackup backups. With this patch, pg_basebackup doesn't write a backup_label file in the data directory, so it doesn't interfere with a pg_start/stop_backup() based backup anymore. backup_label is still included in the backup, but it is injected directly into the tar stream. Heikki Linnakangas, reviewed by Fujii Masao and Magnus Hagander.
2011-01-31 17:13:01 +01:00
#define BACKUP_LABEL_FILE "backup_label"
#define BACKUP_LABEL_OLD "backup_label.old"
Map basebackup tablespaces using a tablespace_map file Windows can't reliably restore symbolic links from a tar format, so instead during backup start we create a tablespace_map file, which is used by the restoring postgres to create the correct links in pg_tblspc. The backup protocol also now has an option to request this file to be included in the backup stream, and this is used by pg_basebackup when operating in tar mode. This is done on all platforms, not just Windows. This means that pg_basebackup will not not work in tar mode against 9.4 and older servers, as this protocol option isn't implemented there. Amit Kapila, reviewed by Dilip Kumar, with a little editing from me.
2015-05-12 15:29:10 +02:00
#define TABLESPACE_MAP "tablespace_map"
#define TABLESPACE_MAP_OLD "tablespace_map.old"
Add pg_promote function This function is able to promote a standby with this new SQL-callable function. Execution access can be granted to non-superusers so that failover tools can observe the principle of least privilege. Catalog version is bumped. Author: Laurenz Albe Reviewed-by: Michael Paquier, Masahiko Sawada Discussion: https://postgr.es/m/6e7c79b3ec916cf49742fb8849ed17cd87aed620.camel@cybertec.at
2018-10-25 02:46:00 +02:00
/* files to signal promotion to primary */
#define PROMOTE_SIGNAL_FILE "promote"
#define FALLBACK_PROMOTE_SIGNAL_FILE "fallback_promote"
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
#endif /* XLOG_H */