1999-09-27 17:48:12 +02:00
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|
/*
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* xlog.h
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*
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2000-11-21 22:16:06 +01:00
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* PostgreSQL transaction log manager
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1999-09-27 17:48:12 +02:00
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*
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2017-01-03 19:48:53 +01:00
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* Portions Copyright (c) 1996-2017, 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
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|
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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2010-09-20 22:08:53 +02:00
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* src/include/access/xlog.h
|
1999-09-27 17:48:12 +02:00
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*/
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#ifndef XLOG_H
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#define XLOG_H
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#include "access/rmgr.h"
|
2000-10-28 18:21:00 +02:00
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|
#include "access/xlogdefs.h"
|
2014-11-06 12:52:08 +01:00
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|
#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"
|
2011-09-09 19:23:41 +02:00
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|
|
#include "datatype/timestamp.h"
|
2006-03-24 05:32:13 +01:00
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|
|
#include "lib/stringinfo.h"
|
2015-05-12 15:29:10 +02:00
|
|
|
#include "nodes/pg_list.h"
|
|
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|
|
#include "storage/fd.h"
|
1999-09-27 17:48:12 +02:00
|
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|
2007-05-20 23:08:19 +02:00
|
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|
|
2005-05-20 16:53:26 +02:00
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|
/* Sync methods */
|
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|
#define SYNC_METHOD_FSYNC 0
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|
#define SYNC_METHOD_FDATASYNC 1
|
2008-05-12 10:35:05 +02:00
|
|
|
#define SYNC_METHOD_OPEN 2 /* for O_SYNC */
|
2005-05-20 16:53:26 +02:00
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|
#define SYNC_METHOD_FSYNC_WRITETHROUGH 3
|
2008-05-12 10:35:05 +02:00
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|
#define SYNC_METHOD_OPEN_DSYNC 4 /* for O_DSYNC */
|
2005-05-20 16:53:26 +02:00
|
|
|
extern int sync_method;
|
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|
2010-02-26 03:01:40 +01:00
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|
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
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|
/*
|
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
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|
* process. This local variable continues to be used in many parts of the
|
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
|
|
|
*/
|
2001-03-22 05:01:46 +01:00
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|
|
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
|
|
|
|
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/*
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* Like InRecovery, standbyState is only valid in the startup process.
|
2010-07-03 22:43:58 +02:00
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|
* In all other processes it will have the value STANDBY_DISABLED (so
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|
* 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
|
2010-08-13 01:24:54 +02:00
|
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|
* 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
|
|
|
*
|
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
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|
*
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|
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|
* When the transaction tracking is initialized, we enter the SNAPSHOT_PENDING
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|
* state. The tracked information might still be incomplete, so we can't allow
|
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* connections yet, but redo functions must update the in-memory state when
|
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* appropriate.
|
|
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|
|
*
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|
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* In SNAPSHOT_READY mode, we have full knowledge of transactions that are
|
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* (or were) running in the master at the current WAL location. Snapshots
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* can be taken, and read-only queries can be run.
|
|
|
|
|
*/
|
|
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|
|
typedef enum
|
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|
|
{
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STANDBY_DISABLED,
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STANDBY_INITIALIZED,
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STANDBY_SNAPSHOT_PENDING,
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STANDBY_SNAPSHOT_READY
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} HotStandbyState;
|
2010-07-03 22:43:58 +02:00
|
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|
|
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
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|
extern HotStandbyState standbyState;
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#define InHotStandby (standbyState >= STANDBY_SNAPSHOT_PENDING)
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2010-03-19 12:05:15 +01:00
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/*
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* Recovery target type.
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* Only set during a Point in Time recovery, not when standby_mode = on
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*/
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typedef enum
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|
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|
{
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RECOVERY_TARGET_UNSET,
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|
RECOVERY_TARGET_XID,
|
2011-02-08 20:39:08 +01:00
|
|
|
RECOVERY_TARGET_TIME,
|
2014-01-25 16:34:04 +01:00
|
|
|
RECOVERY_TARGET_NAME,
|
2016-09-03 18:48:01 +02:00
|
|
|
RECOVERY_TARGET_LSN,
|
2014-01-25 16:34:04 +01:00
|
|
|
RECOVERY_TARGET_IMMEDIATE
|
2010-03-19 12:05:15 +01:00
|
|
|
} RecoveryTargetType;
|
|
|
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|
|
2016-01-21 03:40:44 +01:00
|
|
|
extern XLogRecPtr ProcLastRecPtr;
|
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
|
|
|
|
2011-12-09 13:32:42 +01:00
|
|
|
extern bool reachedConsistency;
|
2011-12-02 09:49:54 +01:00
|
|
|
|
2001-03-16 06:44:33 +01:00
|
|
|
/* these variables are GUC parameters related to XLOG */
|
2015-02-23 17:53:02 +01:00
|
|
|
extern int min_wal_size;
|
|
|
|
|
extern int max_wal_size;
|
2010-04-20 13:15:06 +02:00
|
|
|
extern int wal_keep_segments;
|
2001-03-22 05:01:46 +01:00
|
|
|
extern int XLOGbuffers;
|
2010-04-29 23:36:19 +02:00
|
|
|
extern int XLogArchiveTimeout;
|
2015-02-23 12:55:17 +01:00
|
|
|
extern int wal_retrieve_retry_interval;
|
2004-07-19 04:47:16 +02:00
|
|
|
extern char *XLogArchiveCommand;
|
2010-04-29 23:36:19 +02:00
|
|
|
extern bool EnableHotStandby;
|
2012-01-25 19:02:04 +01:00
|
|
|
extern bool fullPageWrites;
|
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;
|
2010-04-29 23:36:19 +02:00
|
|
|
extern bool log_checkpoints;
|
|
|
|
|
|
2015-02-23 17:53:02 +01:00
|
|
|
extern int CheckPointSegments;
|
|
|
|
|
|
2015-05-15 17:55:24 +02:00
|
|
|
/* Archive modes */
|
|
|
|
|
typedef enum ArchiveMode
|
|
|
|
|
{
|
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) */
|
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,
|
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;
|
2016-05-25 04:48:47 +02:00
|
|
|
|
|
|
|
|
extern PGDLLIMPORT int wal_level;
|
2001-03-16 06:44:33 +01:00
|
|
|
|
2015-06-12 16:11:51 +02:00
|
|
|
/* Is WAL archiving enabled (always or only while server is running normally)? */
|
2015-05-15 17:55:24 +02:00
|
|
|
#define XLogArchivingActive() \
|
2016-03-01 02:01:54 +01:00
|
|
|
(AssertMacro(XLogArchiveMode == ARCHIVE_MODE_OFF || wal_level >= WAL_LEVEL_REPLICA), XLogArchiveMode > ARCHIVE_MODE_OFF)
|
2015-06-12 16:11:51 +02:00
|
|
|
/* Is WAL archiving enabled always (even during recovery)? */
|
|
|
|
|
#define XLogArchivingAlways() \
|
2016-03-01 02:01:54 +01:00
|
|
|
(AssertMacro(XLogArchiveMode == ARCHIVE_MODE_OFF || wal_level >= WAL_LEVEL_REPLICA), XLogArchiveMode == ARCHIVE_MODE_ALWAYS)
|
2007-11-15 22:14:46 +01:00
|
|
|
#define XLogArchiveCommandSet() (XLogArchiveCommand[0] != '\0')
|
2004-07-19 04:47:16 +02:00
|
|
|
|
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?
|
2010-01-15 10:19:10 +01:00
|
|
|
*/
|
2016-03-01 02:01:54 +01:00
|
|
|
#define XLogIsNeeded() (wal_level >= WAL_LEVEL_REPLICA)
|
2010-01-15 10:19:10 +01:00
|
|
|
|
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
|
2013-12-20 19:33:16 +01:00
|
|
|
* them if forced by wal_log_hints=on.
|
2013-12-13 15:26:14 +01:00
|
|
|
*/
|
2014-01-02 02:17:00 +01:00
|
|
|
#define XLogHintBitIsNeeded() (DataChecksumsEnabled() || wal_log_hints)
|
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? */
|
2016-03-01 02:01:54 +01:00
|
|
|
#define XLogStandbyInfoActive() (wal_level >= WAL_LEVEL_REPLICA)
|
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)
|
|
|
|
|
|
2004-01-06 18:26:23 +01:00
|
|
|
#ifdef WAL_DEBUG
|
2004-08-29 07:07:03 +02:00
|
|
|
extern bool XLOG_DEBUG;
|
2004-01-06 18:26:23 +01:00
|
|
|
#endif
|
2001-03-16 06:44:33 +01:00
|
|
|
|
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 */
|
2007-11-15 22:14:46 +01:00
|
|
|
#define CHECKPOINT_IS_SHUTDOWN 0x0001 /* Checkpoint is for shutdown */
|
2010-02-26 03:01:40 +01:00
|
|
|
#define CHECKPOINT_END_OF_RECOVERY 0x0002 /* Like shutdown checkpoint,
|
|
|
|
|
* but issued at end of WAL
|
|
|
|
|
* recovery */
|
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 */
|
2014-10-21 00:20:08 +02:00
|
|
|
#define CHECKPOINT_FLUSH_ALL 0x0010 /* Flush all pages, including those
|
|
|
|
|
* belonging to unlogged tables */
|
2007-06-30 21:12:02 +02:00
|
|
|
/* These are important to RequestCheckpoint */
|
2014-10-21 00:20:08 +02:00
|
|
|
#define CHECKPOINT_WAIT 0x0020 /* Wait for completion */
|
2007-06-30 21:12:02 +02:00
|
|
|
/* These indicate the cause of a checkpoint request */
|
2014-10-21 00:20:08 +02:00
|
|
|
#define CHECKPOINT_CAUSE_XLOG 0x0040 /* XLOG consumption */
|
|
|
|
|
#define CHECKPOINT_CAUSE_TIME 0x0080 /* Elapsed time */
|
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 */
|
|
|
|
|
|
|
|
|
|
|
2007-06-30 21:12:02 +02:00
|
|
|
/* Checkpoint statistics */
|
|
|
|
|
typedef struct CheckpointStatsData
|
|
|
|
|
{
|
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 */
|
2007-06-30 21:12:02 +02:00
|
|
|
TimestampTz ckpt_sync_end_t; /* end of fsyncs */
|
2007-11-15 22:14:46 +01:00
|
|
|
TimestampTz ckpt_end_t; /* end of checkpoint */
|
2007-06-30 21:12:02 +02:00
|
|
|
|
2007-11-15 22:14:46 +01:00
|
|
|
int ckpt_bufs_written; /* # of buffers written */
|
2007-06-30 21:12:02 +02:00
|
|
|
|
|
|
|
|
int ckpt_segs_added; /* # of new xlog segments created */
|
2007-11-15 22:14:46 +01:00
|
|
|
int ckpt_segs_removed; /* # of xlog segments deleted */
|
|
|
|
|
int ckpt_segs_recycled; /* # of xlog segments recycled */
|
2010-12-14 15:25:25 +01:00
|
|
|
|
2011-04-10 17:42:00 +02:00
|
|
|
int ckpt_sync_rels; /* # of relations synced */
|
|
|
|
|
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. */
|
2007-11-15 23:25:18 +01:00
|
|
|
} CheckpointStatsData;
|
2007-06-30 21:12:02 +02:00
|
|
|
|
|
|
|
|
extern CheckpointStatsData CheckpointStats;
|
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,
|
|
|
|
|
XLogRecPtr fpw_lsn,
|
|
|
|
|
uint8 flags);
|
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);
|
2007-05-30 22:12:03 +02:00
|
|
|
extern bool XLogNeedsFlush(XLogRecPtr RecPtr);
|
2013-05-29 22:58:43 +02:00
|
|
|
extern int XLogFileInit(XLogSegNo segno, bool *use_existent, bool use_lock);
|
2012-06-24 17:06:38 +02:00
|
|
|
extern int XLogFileOpen(XLogSegNo segno);
|
2010-01-15 10:19:10 +01:00
|
|
|
|
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);
|
2010-07-30 00:27:27 +02:00
|
|
|
extern void XLogSetAsyncXactLSN(XLogRecPtr record);
|
2014-02-01 04:45:17 +01:00
|
|
|
extern void XLogSetReplicationSlotMinimumLSN(XLogRecPtr lsn);
|
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);
|
2014-09-19 15:17:12 +02:00
|
|
|
extern const char *xlog_identify(uint8 info);
|
2000-11-21 22:16:06 +01:00
|
|
|
|
2012-06-24 17:06:38 +02:00
|
|
|
extern void issue_xlog_fsync(int fd, XLogSegNo segno);
|
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);
|
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);
|
2009-06-26 22:29:04 +02:00
|
|
|
extern bool XLogInsertAllowed(void);
|
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);
|
2012-01-11 10:00:53 +01:00
|
|
|
extern XLogRecPtr GetXLogInsertRecPtr(void);
|
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);
|
2011-12-31 14:30:26 +01:00
|
|
|
extern TimestampTz GetCurrentChunkReplayStartTime(void);
|
2012-06-24 17:06:38 +02:00
|
|
|
extern char *XLogFileNameP(TimeLineID tli, XLogSegNo segno);
|
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
|
|
|
|
2000-11-21 22:16:06 +01:00
|
|
|
extern void UpdateControlFile(void);
|
2010-01-15 10:19:10 +01:00
|
|
|
extern uint64 GetSystemIdentifier(void);
|
2013-03-22 14:54:07 +01:00
|
|
|
extern bool DataChecksumsEnabled(void);
|
2013-02-11 21:50:15 +01:00
|
|
|
extern XLogRecPtr GetFakeLSNForUnloggedRel(void);
|
2005-08-21 01:26:37 +02:00
|
|
|
extern Size XLOGShmemSize(void);
|
2000-11-21 22:16:06 +01:00
|
|
|
extern void XLOGShmemInit(void);
|
|
|
|
|
extern void BootStrapXLOG(void);
|
|
|
|
|
extern void StartupXLOG(void);
|
2003-12-12 19:45:10 +01:00
|
|
|
extern void ShutdownXLOG(int code, Datum arg);
|
2004-05-27 19:12:57 +02:00
|
|
|
extern void InitXLOGAccess(void);
|
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);
|
2011-02-08 20:39:08 +01:00
|
|
|
extern XLogRecPtr XLogRestorePoint(const char *rpName);
|
2012-01-25 19:02:04 +01:00
|
|
|
extern void UpdateFullPageWrites(void);
|
2014-11-06 12:52:08 +01:00
|
|
|
extern void GetFullPageWriteInfo(XLogRecPtr *RedoRecPtr_p, bool *doPageWrites_p);
|
2002-03-15 20:20:36 +01:00
|
|
|
extern XLogRecPtr GetRedoRecPtr(void);
|
2007-06-28 02:02:40 +02:00
|
|
|
extern XLogRecPtr GetInsertRecPtr(void);
|
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);
|
2006-08-21 18:16:31 +02:00
|
|
|
extern void GetNextXidAndEpoch(TransactionId *xid, uint32 *epoch);
|
2015-09-09 15:51:44 +02:00
|
|
|
extern void RemovePromoteSignalFiles(void);
|
2000-11-21 22:16:06 +01:00
|
|
|
|
2011-02-16 03:28:48 +01:00
|
|
|
extern bool CheckPromoteSignal(void);
|
2010-09-15 12:35:05 +02:00
|
|
|
extern void WakeupRecovery(void);
|
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
|
|
|
|
2016-03-30 03:16:12 +02:00
|
|
|
extern void XLogRequestWalReceiverReply(void);
|
|
|
|
|
|
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);
|
|
|
|
|
|
2011-01-31 17:13:01 +01:00
|
|
|
/*
|
|
|
|
|
* Starting/stopping a base backup
|
|
|
|
|
*/
|
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,
|
2016-06-10 00:02:36 +02:00
|
|
|
TimeLineID *starttli_p, StringInfo labelfile, DIR *tblspcdir,
|
|
|
|
|
List **tablespaces, StringInfo tblspcmapfile, bool infotbssize,
|
2015-05-12 15:29:10 +02:00
|
|
|
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,
|
|
|
|
|
TimeLineID *stoptli_p);
|
2011-01-09 21:00:28 +01:00
|
|
|
extern void do_pg_abort_backup(void);
|
|
|
|
|
|
2011-01-31 17:13:01 +01:00
|
|
|
/* File path names (all relative to $PGDATA) */
|
|
|
|
|
#define BACKUP_LABEL_FILE "backup_label"
|
|
|
|
|
#define BACKUP_LABEL_OLD "backup_label.old"
|
|
|
|
|
|
2015-05-12 15:29:10 +02:00
|
|
|
#define TABLESPACE_MAP "tablespace_map"
|
|
|
|
|
#define TABLESPACE_MAP_OLD "tablespace_map.old"
|
|
|
|
|
|
2001-11-05 18:46:40 +01:00
|
|
|
#endif /* XLOG_H */
|
