The double quotes used for the wait event names are not required, as
the values quoted are made of single words. The files generated by
generate-wait_event_types.pl (pgstat_wait_event.c, wait_event_types.h
and wait_event_types.sgml) are exactly the same before and after this
commit, hence the wait event names and the enum elements have the same
names as before.
Discussion: https://postgr.es/m/ZK9S3jFEV1X797Ll@paquier.xyz
The first check on the enum values was not necessary as the values set
in wait_event_names.txt for the classes LWLock and Lock were able to
satisfy the check. The second check when generating the C and header
files is now based on a match of the class names, making it simpler to
understand.
Author: Masahiro Ikeda, Michael Paquier
Discussion: https://postgr.es/m/eaf82a85c0ef1b55dc3b651d3f7b867a@oss.nttdata.com
This commit adds a new type of parallel message 'P' to allow a
parallel worker to poke at a leader to update the progress.
Currently it supports only incremental progress reporting but it's
possible to allow for supporting of other backend progress APIs in the
future.
There are no users of this new message type as of this commit. That
will follow in future commits.
Idea from Andres Freund.
Author: Sami Imseih
Reviewed by: Michael Paquier, Masahiko Sawada
Discussion: https://www.postgresql.org/message-id/flat/5478DFCD-2333-401A-B2F0-0D186AB09228@amazon.com
The header file wait_event_types.h was generated without a newline at
its end, which was inconsistent with all the other things generated
automatically.
Per offline gripe from Nathan Bossart.
The documentation and the code is generated automatically from a new
file called wait_event_names.txt, formatted in sections dedicated to
each wait event class (Timeout, Lock, IO, etc.) with three tab-separated
fields:
- C symbol in enums
- Format in the system views
- Description in the docs
Using this approach has several advantages, as we have proved to be
rather bad in maintaining this area of the tree across the years:
- The order of each item in the documentation and the code, which should
be alphabetical, has become incorrect multiple times, and the script
generating the code and documentation has a few rules to enforce that,
making the maintenance a no-brainer.
- Some wait events were added to the code, but not documented, so this
cannot be missed now.
- The order of the tables for each wait event class is enforced in the
documentation (the input .txt file does so as well for clarity, though
this is not mandatory).
- Less code, shaving 1.2k lines from the tree, with 1/3 of the savings
coming from the code, the rest from the documentation.
The wait event types "Lock" and "LWLock" still have their own code path
for their code, hence only the documentation is created for them. These
classes are listed with a special marker called WAIT_EVENT_DOCONLY in
the input file.
Adding a new wait event now requires only an update of
wait_event_names.txt, with "Lock" and "LWLock" treated as exceptions.
This commit has been tested with configure/Makefile, the CI and VPATH
build. clean, distclean and maintainer-clean were working fine.
Author: Bertrand Drouvot, Michael Paquier
Discussion: https://postgr.es/m/77a86b3a-c4a8-5f5d-69b9-d70bbf2e9b98@gmail.com
The following changes are done:
- Addition of WaitEventBufferPin and WaitEventExtension, that hold a
list of wait events related to each category.
- Addition of two functions that encapsulate the list of wait events for
each category.
- Rename BUFFER_PIN to BUFFERPIN (only this wait event class used an
underscore, requiring a specific rule in the automation script).
These changes make a bit easier the automatic generation of all the code
and documentation related to wait events, as all the wait event
categories are now controlled by consistent structures and functions.
Author: Bertrand Drouvot
Discussion: https://postgr.es/m/c6f35117-4b20-4c78-1df5-d3056010dcf5@gmail.com
Discussion: https://postgr.es/m/77a86b3a-c4a8-5f5d-69b9-d70bbf2e9b98@gmail.com
Previously stats in the startup process would only get reported during
shutdown of the startup process. It has been that way for a long time, but
became a lot more noticeable with the new pg_stat_io view, which separates out
IO done by different backend types...
While replaying after every XLOG_RUNNING_XACTS isn't the prettiest approach,
it has the advantage of being quite easy. Given that we're well past feature
freeze...
It's not a problem that we don't report stats more frequently with
wal_level=minimal, in that case stats can't be read before the stats process
has shut down.
Besides the above, this commit also changes pgstat_report_stat() to acquire
the timestamp with GetCurrentTimestamp() instead of
GetCurrentTransactionStopTimestamp().
Thanks to Melih Mutlu, Kyotaro Horiguchi for prototypes of other approaches to
solving this issue.
Reported-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Discussion: https://postgr.es/m/5315aedc-fbca-1556-c5de-dc2e00b23a14@oss.nttdata.com
Run pgindent, pgperltidy, and reformat-dat-files.
This set of diffs is a bit larger than typical. We've updated to
pg_bsd_indent 2.1.2, which properly indents variable declarations that
have multi-line initialization expressions (the continuation lines are
now indented one tab stop). We've also updated to perltidy version
20230309 and changed some of its settings, which reduces its desire to
add whitespace to lines to make assignments etc. line up. Going
forward, that should make for fewer random-seeming changes to existing
code.
Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
28e626bde0 added the concept of IOOps but neglected to include writeback
operations. ac8d53dae5 added time spent doing these I/O operations. Without
counting writeback, checkpointer write time in the log often differed
substantially from that in pg_stat_io. To fix this, add IOOp IOOP_WRITEBACK
and track writeback in pg_stat_io.
Bumps catversion.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20230419172326.dhgyo4wrrhulovt6%40awork3.anarazel.de
An update of the GUC stats_fetch_consistency in a transaction would be
able to trigger an assertion when doing cache->snapshot. In this case,
when retrieving a pgstat entry after the switch, a new snapshot would be
rebuilt, confusing pgstat_build_snapshot() because a snapshot is already
cached with an unexpected mode ("cache").
In order to fix this problem, this commit adds a flag to force a
snapshot clear each time this GUC is changed. Some tests are added to
check, while on it.
Some optimizations in avoiding the snapshot clear should be possible
depending on what is cached and the current GUC value, I guess, but this
solution is simple, and ensures that the state of the cache is updated
each time a new pgstat entry is fetched, hence being consistent with the
level wanted by the client that has set the GUC.
Note that cache->none and snapshot->none would not cause issues, as
fetching a pgstat entry would be retrieved from shared memory on the
second attempt, however a snapshot would still be cached. Similarly,
none->snapshot and none->cache would build a new snapshot on the second
fetch attempt. Finally, snapshot->cache would cache a new snapshot on
the second attempt.
Reported-by: Alexander Lakhin
Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/17804-2a118cd046f2d0e5@postgresql.org
backpatch-through: 15
Make sure that function declarations use names that exactly match the
corresponding names from function definitions in a few places. These
inconsistencies were all introduced relatively recently, after the code
base had parameter name mismatches fixed in bulk (see commits starting
with commits 4274dc22 and 035ce1fe).
pg_bsd_indent still has a couple of similar inconsistencies, which I
(pgeoghegan) have left untouched for now.
Like all earlier commits that cleaned up function parameter names, this
commit was written with help from clang-tidy.
This reverts commit 3d03b24c3 (Revert Add support for Kerberos
credential delegation) which was committed on the grounds of concern
about portability, but on further review and discussion, it's clear that
we are better off explicitly requiring MIT Kerberos as that appears to
be the only GSSAPI library currently that's under proper maintenance
and ongoing development. The API used for storing credentials was added
to MIT Kerberos over a decade ago while for the other libraries which
appear to be mainly based on Heimdal, which exists explicitly to be a
re-implementation of MIT Kerberos, the API never made it to a released
version (even though it was added to the Heimdal git repo over 5 years
ago..).
This post-feature-freeze change was approved by the RMT.
Discussion: https://postgr.es/m/ZDDO6jaESKaBgej0%40tamriel.snowman.net
This reverts commit 3d4fa227bc.
Per discussion and buildfarm, this depends on APIs that seem to not
be available on at least one platform (NetBSD). Should be certainly
possible to rework to be optional on that platform if necessary but bit
late for that at this point.
Discussion: https://postgr.es/m/3286097.1680922218@sss.pgh.pa.us
During WAL replay on the standby, when a conflict with a logical slot is
identified, invalidate such slots. There are two sources of conflicts:
1) Using the information added in 6af1793954, logical slots are invalidated if
required rows are removed
2) wal_level on the primary server is reduced to below logical
Uses the infrastructure introduced in the prior commit. FIXME: add commit
reference.
Change InvalidatePossiblyObsoleteSlot() to use a recovery conflict to
interrupt use of a slot, if called in the startup process. The new recovery
conflict is added to pg_stat_database_conflicts, as confl_active_logicalslot.
See 6af1793954 for an overall design of logical decoding on a standby.
Bumps catversion for the addition of the pg_stat_database_conflicts column.
Bumps PGSTAT_FILE_FORMAT_ID for the same reason.
Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Author: Amit Khandekar <amitdkhan.pg@gmail.com> (in an older version)
Reviewed-by: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Fabrízio de Royes Mello <fabriziomello@gmail.com>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/20230407075009.igg7be27ha2htkbt@awork3.anarazel.de
Support GSSAPI/Kerberos credentials being delegated to the server by a
client. With this, a user authenticating to PostgreSQL using Kerberos
(GSSAPI) credentials can choose to delegate their credentials to the
PostgreSQL server (which can choose to accept them, or not), allowing
the server to then use those delegated credentials to connect to
another service, such as with postgres_fdw or dblink or theoretically
any other service which is able to be authenticated using Kerberos.
Both postgres_fdw and dblink are changed to allow non-superuser
password-less connections but only when GSSAPI credentials have been
delegated to the server by the client and GSSAPI is used to
authenticate to the remote system.
Authors: Stephen Frost, Peifeng Qiu
Reviewed-By: David Christensen
Discussion: https://postgr.es/m/CO1PR05MB8023CC2CB575E0FAAD7DF4F8A8E29@CO1PR05MB8023.namprd05.prod.outlook.com
a9c70b46db and 8aaa04b32S added counting of IO operations to a new view,
pg_stat_io. Now, add IO timing for reads, writes, extends, and fsyncs to
pg_stat_io as well.
This combines the tracking for pgBufferUsage with the tracking for pg_stat_io
into a new function pgstat_count_io_op_time(). This should make it a bit
easier to avoid the somewhat costly instr_time conversion done for
pgBufferUsage.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/flat/CAAKRu_ay5iKmnbXZ3DsauViF3eMxu4m1oNnJXqV_HyqYeg55Ww%40mail.gmail.com
The primary bottlenecks for relation extension are:
1) The extension lock is held while acquiring a victim buffer for the new
page. Acquiring a victim buffer can require writing out the old page
contents including possibly needing to flush WAL.
2) When extending via ReadBuffer() et al, we write a zero page during the
extension, and then later write out the actual page contents. This can
nearly double the write rate.
3) The existing bulk relation extension infrastructure in hio.c just amortized
the cost of acquiring the relation extension lock, but none of the other
costs.
Unfortunately 1) cannot currently be addressed in a central manner as the
callers to ReadBuffer() need to acquire the extension lock. To address that,
this this commit moves the responsibility for acquiring the extension lock
into bufmgr.c functions. That allows to acquire the relation extension lock
for just the required time. This will also allow us to improve relation
extension further, without changing callers.
The reason we write all-zeroes pages during relation extension is that we hope
to get ENOSPC errors earlier that way (largely works, except for CoW
filesystems). It is easier to handle out-of-space errors gracefully if the
page doesn't yet contain actual tuples. This commit addresses 2), by using the
recently introduced smgrzeroextend(), which extends the relation, without
dirtying the kernel page cache for all the extended pages.
To address 3), this commit introduces a function to extend a relation by
multiple blocks at a time.
There are three new exposed functions: ExtendBufferedRel() for extending the
relation by a single block, ExtendBufferedRelBy() to extend a relation by
multiple blocks at once, and ExtendBufferedRelTo() for extending a relation up
to a certain size.
To avoid duplicating code between ReadBuffer(P_NEW) and the new functions,
ReadBuffer(P_NEW) now implements relation extension with
ExtendBufferedRel(), using a flag to tell ExtendBufferedRel() that the
relation lock is already held.
Note that this commit does not yet lead to a meaningful performance or
scalability improvement - for that uses of ReadBuffer(P_NEW) will need to be
converted to ExtendBuffered*(), which will be done in subsequent commits.
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/20221029025420.eplyow6k7tgu6he3@awork3.anarazel.de
Among other things, this should make it easier to calculate a useful cache hit
ratio by excluding buffer reads via buffer access strategies. As buffer access
strategies reuse buffers (and thus evict the prior buffer contents), it is
normal to see reads on repeated scans of the same data.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CAAKRu_beMa9Hzih40%3DXPYqhDVz6tsgUGTrhZXRo%3Dunp%2Bszb%3DUA%40mail.gmail.com
In instr_time.h it is stated that:
* When summing multiple measurements, it's recommended to leave the
* running sum in instr_time form (ie, use INSTR_TIME_ADD or
* INSTR_TIME_ACCUM_DIFF) and convert to a result format only at the end.
The reason for that is that converting to microseconds is not cheap, and can
loose precision. Therefore this commit changes 'PendingWalStats' to use
'instr_time' instead of 'PgStat_Counter' while accumulating 'wal_write_time'
and 'wal_sync_time'.
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/1feedb83-7aa9-cb4b-5086-598349d3f555@gmail.com
The "partitions_total" and "partitions_done" fields were updated
as though the current level of partitioning was the only one.
In multi-level cases, not only could partitions_total change
over the course of the command, but partitions_done could go
backwards or exceed the currently-reported partitions_total.
Fix by setting partitions_total to the total number of direct
and indirect children once at command start, and then just
incrementing partitions_done at appropriate points. Invent
a new progress monitoring function "pgstat_progress_incr_param"
to simplify doing the latter. We can avoid adding cost for the
former when doing CREATE INDEX, because ProcessUtility already
enumerates the children and it's pretty easy to pass the count
down to DefineIndex. In principle the same could be done in
ALTER TABLE, but that's structurally difficult; for now, just
eat the cost of an extra find_all_inheritors scan in that case.
Ilya Gladyshev and Justin Pryzby
Discussion: https://postgr.es/m/a15f904a70924ffa4ca25c3c744cff31e0e6e143.camel@gmail.com
This commit renames the members of a few pgstat structures related to
functions and relations, by respectively removing their prefix "f_" and
"t_". The statistics for functions and relations and handled in their
own file, and pgstatfuncs.c associates each field in a structure
variable named based on the object type handled, so no information is
lost with this rename.
This will help with some of the refactoring aimed for pgstatfuncs.c, as
this makes more consistent the field names with the SQL functions
retrieving them.
Author: Bertrand Drouvot
Reviewed-by: Michael Paquier, Melanie Plageman
Discussion: https://postgr.es/m/9142f62a-a422-145c-bde0-b5bc498a4ada@gmail.com
Add pgstat counter to track row updates that result in the successor
version going to a new heap page, leaving behind an original version
whose t_ctid points to the new version. The current count is shown by
the n_tup_newpage_upd column of each of the pg_stat_*_tables views.
The new n_tup_newpage_upd column complements the existing n_tup_hot_upd
and n_tup_upd columns. Tables that have high n_tup_newpage_upd values
(relative to n_tup_upd) are good candidates for tuning heap fillfactor.
Corey Huinker, with small tweaks by me.
Author: Corey Huinker <corey.huinker@gmail.com>
Reviewed-By: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CADkLM=ded21M9iZ36hHm-vj2rE2d=zcKpUQMds__Xm2pxLfHKA@mail.gmail.com
* Commit 3048898e dropped -ING from PHJ wait event names. Update the
corresponding barrier phases names to match.
* Rename the "DONE" phases to "FREE". That's symmetrical with
"ALLOCATE", and names the activity that actually happens in that phase
(as we do for the other phases) rather than a state. The bug fixed by
commit 8d578b9b might have been more obvious with this name.
* Rename the batch/bucket growth barriers' "ALLOCATE" phases to
"REALLOCATE", a better description of what they do.
* Update the high level comments about phases to highlight phases
are executed by a single process with an asterisk (mostly memory
management phases).
No behavior change, as this is just improving internal identifiers. The
only user-visible sign of this is that a couple of wait events' display
names change from "...Allocate" to "...Reallocate" in pg_stat_activity,
to stay in sync with the internal names.
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKG%2BMDpwF2Eo2LAvzd%3DpOh81wUTsrwU1uAwR-v6OGBB6%2B7g%40mail.gmail.com
This structure included only PgStat_FunctionCounts, and removing it
facilitates some upcoming refactoring for pgstatfuncs.c to use more
macros rather that mostly-duplicated functions.
Author: Bertrand Drouvot
Reviewed-by: Nathan Bossart
Discussion: https://postgr.es/m/11d531fe-52fc-c6ea-7e8e-62f1b6ec626e@gmail.com
Some clang versions whine about comparing an enum variable to
a value outside the range of the enum, on the grounds that the
result must be constant. In the cases we fix here, the loops
will terminate only if the enum variable can in fact hold a
value one beyond its declared range. While that's very likely
to always be true for these enum types, it still seems like a
poor coding practice to assume it; so use "int" loop variables
instead to silence the warnings. (This matches what we've done
in other places, for example loops over the range of ForkNumber.)
While at it, let's drop the XXX_FIRST macros for these enums and just
write zeroes for the loop start values. The apparent flexibility
seems rather illusory given that iterating up to one-less-than-
the-number-of-values is only correct for a zero-based range.
Melanie Plageman
Discussion: https://postgr.es/m/20520.1677435600@sss.pgh.pa.us
d9d7fe68d3 made use of an existing wait event when sending data from the
apply worker, but we should have invented a new wait event since this is a
new place to wait.
This patch corrects the mistake by using a new wait event
"LogicalApplySendData".
Author: Hou Zhijie
Reviewed-by: Peter Smith
Discussion: https://postgr.es/m/CA+TgmobWzbr9H3yN3dLVckviEZKemPwd+XyCFKEgyZQZhgP66Q@mail.gmail.com
This commit adds the infrastructure for more detailed IO statistics. The calls
to actually count IOs, a system view to access the new statistics,
documentation and tests will be added in subsequent commits, to make review
easier.
While we already had some IO statistics, e.g. in pg_stat_bgwriter and
pg_stat_database, they did not provide sufficient detail to understand what
the main sources of IO are, or whether configuration changes could avoid
IO. E.g., pg_stat_bgwriter.buffers_backend does contain the number of buffers
written out by a backend, but as that includes extending relations (always
done by backends) and writes triggered by the use of buffer access strategies,
it cannot easily be used to tune background writer or checkpointer. Similarly,
pg_stat_database.blks_read cannot easily be used to tune shared_buffers /
compute a cache hit ratio, as the use of buffer access strategies will often
prevent a large fraction of the read blocks to end up in shared_buffers.
The new IO statistics count IO operations (evict, extend, fsync, read, reuse,
and write), and are aggregated for each combination of backend type (backend,
autovacuum worker, bgwriter, etc), target object of the IO (relations, temp
relations) and context of the IO (normal, vacuum, bulkread, bulkwrite).
What is tracked in this series of patches, is sufficient to perform the
aforementioned analyses. Further details, e.g. tracking the number of buffer
hits, would make that even easier, but was left out for now, to keep the scope
of the already large patchset manageable.
Bumps PGSTAT_FILE_FORMAT_ID.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20200124195226.lth52iydq2n2uilq@alap3.anarazel.de
Currently, for large transactions, the publisher sends the data in
multiple streams (changes divided into chunks depending upon
logical_decoding_work_mem), and then on the subscriber-side, the apply
worker writes the changes into temporary files and once it receives the
commit, it reads from those files and applies the entire transaction. To
improve the performance of such transactions, we can instead allow them to
be applied via parallel workers.
In this approach, we assign a new parallel apply worker (if available) as
soon as the xact's first stream is received and the leader apply worker
will send changes to this new worker via shared memory. The parallel apply
worker will directly apply the change instead of writing it to temporary
files. However, if the leader apply worker times out while attempting to
send a message to the parallel apply worker, it will switch to
"partial serialize" mode - in this mode, the leader serializes all
remaining changes to a file and notifies the parallel apply workers to
read and apply them at the end of the transaction. We use a non-blocking
way to send the messages from the leader apply worker to the parallel
apply to avoid deadlocks. We keep this parallel apply assigned till the
transaction commit is received and also wait for the worker to finish at
commit. This preserves commit ordering and avoid writing to and reading
from files in most cases. We still need to spill if there is no worker
available.
This patch also extends the SUBSCRIPTION 'streaming' parameter so that the
user can control whether to apply the streaming transaction in a parallel
apply worker or spill the change to disk. The user can set the streaming
parameter to 'on/off', or 'parallel'. The parameter value 'parallel' means
the streaming will be applied via a parallel apply worker, if available.
The parameter value 'on' means the streaming transaction will be spilled
to disk. The default value is 'off' (same as current behaviour).
In addition, the patch extends the logical replication STREAM_ABORT
message so that abort_lsn and abort_time can also be sent which can be
used to update the replication origin in parallel apply worker when the
streaming transaction is aborted. Because this message extension is needed
to support parallel streaming, parallel streaming is not supported for
publications on servers < PG16.
Author: Hou Zhijie, Wang wei, Amit Kapila with design inputs from Sawada Masahiko
Reviewed-by: Sawada Masahiko, Peter Smith, Dilip Kumar, Shi yu, Kuroda Hayato, Shveta Mallik
Discussion: https://postgr.es/m/CAA4eK1+wyN6zpaHUkCLorEWNx75MG0xhMwcFhvjqm2KURZEAGw@mail.gmail.com
A new function pg_stat_get_backend_subxact() can be used to get
information about the number of subtransactions in the cache of
a particular backend and whether that cache has overflowed. This
can be useful for tracking down performance problems that can
result from overflowed snapshots.
Dilip Kumar, reviewed by Zhihong Yu, Nikolay Samokhvalov,
Justin Pryzby, Nathan Bossart, Ashutosh Sharma, Julien
Rouhaud. Additional design comments from Andres Freund,
Tom Lane, Bruce Momjian, and David G. Johnston.
Discussion: http://postgr.es/m/CAFiTN-ut0uwkRJDQJeDPXpVyTWD46m3gt3JDToE02hTfONEN=Q@mail.gmail.com
The same code pattern is repeated 21 times for int64 counters (0 for
missing entry) and 5 times for doubles (0 for missing entry) on database
entries. This code is switched to use macros for the basic code
instead, shaving a few hundred lines of originally-duplicated code
patterns. The function names remain the same, but some fields of
PgStat_StatDBEntry have to be renamed to cope with the new style.
This is in the same spirit as 83a1a1b.
Author: Michael Paquier
Reviewed-by: Nathan Bossart, Bertrand Drouvot
Discussion: https://postgr.es/m/Y46stlxQ2LQE20Na@paquier.xyz
The same code pattern is repeated 17 times for int64 counters (0 for
missing entry) and 5 times for timestamps (NULL for missing entry) on
table entries. This code is switched to use a macro for the basic code
instead, shaving a few hundred lines of originally-duplicated code. The
function names remain the same, but some fields of PgStat_StatTabEntry
have to be renamed to cope with the new style.
Author: Bertrand Drouvot
Reviewed-by: Nathan Bossart
Discussion: https:/postgr.es/m/20221204173207.GA2669116@nathanxps13
The lwlock wait queue scalability issue fixed in a4adc31f69 was quite hard to
find because of the exponential backoff and because we adjust spins_per_delay
over time within a backend.
To make it easier to find similar issues in the future, add a wait event for
the pg_usleep() in perform_spin_delay(). Showing a wait event while spinning
without sleeping would increase the overhead of spinlocks, which we do not
want.
We may at some later point want to have more granular wait events, but that'd
be a substantial amount of work. This provides at least some insights into
something currently hard to observe.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
https://postgr.es/m/20221120204310.xywrhyxyytsajuuq@awork3.anarazel.de
As the list of shared relations is fixed, we can just dispatch based
IsSharedRelation(), instead of first trying to look up stats for a non-shared
rel and falling back to shared stats.
Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de
Discussion: https://postgr.es/m/8c1851a2-a98e-e1bc-7729-37b0b95f66ec@gmail.com
We have various requirements when using a dlist_head to keep track of the
number of items in the list. This, traditionally, has been done by
maintaining a counter variable in the calling code. Here we tidy this up
by adding "dclist", which is very similar to dlist but also keeps track of
the number of items stored in the list.
Callers may use the new dclist_count() function when they need to know how
many items are stored. Obtaining the count is an O(1) operation.
For simplicity reasons, dclist and dlist both use dlist_node as their node
type and dlist_iter/dlist_mutable_iter as their iterator type. dclists
have all of the same functionality as dlists except there is no function
named dclist_delete(). To remove an item from a list dclist_delete_from()
must be used. This requires knowing which dclist the given item is stored
in.
Additionally, here we also convert some dlists where additional code
exists to keep track of the number of items stored and to make these use
dclists instead.
Author: David Rowley
Reviewed-by: Bharath Rupireddy, Aleksander Alekseev
Discussion: https://postgr.es/m/CAApHDvrtVxr+FXEX0VbViCFKDGxA3tWDgw9oFewNXCJMmwLjLg@mail.gmail.com
It can be useful to know when a relation has last been used, e.g., when
evaluating whether an index is still required. It was already possible to
infer the time of the last usage by tracking, e.g.,
pg_stat_all_indexes.idx_scan over time. But far from everybody does so.
To make it easier to detect the last time a relation has been scanned, track
that time in each relation's pgstat entry. To minimize overhead a) the
timestamp is updated only when the backend pending stats entry is flushed to
shared stats b) the last transaction's stop timestamp is used as the
timestamp.
Bumps catalog and stats format versions.
Author: Dave Page <dpage@pgadmin.org>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Bruce Momjian <bruce@momjian.us>
Reviewed-by: Vik Fearing <vik@postgresfriends.org>
Discussion: https://postgr.es/m/CA+OCxozrVHNFVEPkweUHMZje+t1tfY816d9MZYc6eZwOOusOaQ@mail.gmail.com
Previously PgStat_StatReplSlotEntry contained the slotname, which was mainly
used when writing out the stats during shutdown, to identify the slot in the
serialized data (at runtime the index in ReplicationSlotCtl->replication_slots
is used, but that can change during a restart). Unfortunately the slotname was
overwritten when the slot's stats were reset.
That turned out to only cause "real" problems if the slot was active during
the reset, triggering an assertion failure at the next
pgstat_report_replslot(). In other paths the stats were re-initialized during
pgstat_acquire_replslot().
Fix this by removing slotname from PgStat_StatReplSlotEntry. Instead we can
get the slot's name from the slot itself. Besides fixing a bug, this also is
architecturally cleaner (a name is not really statistics). This is safe
because stats, for a slot removed while shut down, will not be restored at
startup.
In 15 the slotname is not removed, but renamed, to avoid changing the stats
format. In master, bump PGSTAT_FILE_FORMAT_ID.
This commit does not contain a test for the fix. I think this can only be
tested by a tap test starting pg_recvlogical in the background and checking
pg_recvlogical's output. That type of test is notoriously hard to be reliable,
so committing it shortly before the release is wrapped seems like a bad idea.
Reported-by: Jaime Casanova <jcasanov@systemguards.com.ec>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/YxfagaTXUNa9ggLb@ahch-to
Backpatch: 15-, where the bug was introduced in 5891c7a8ed
Previously, the subscription stats entry was created when the first
stats, i.e., an error on apply worker or tablesync worker, were
reported. Therefore, the stats_reset field was not updated by
pg_stat_reset_subscription_stats() if the stats entry was not
populated yet, which was different behavior than other statistics.
This change creates the subscription stats entry and initializes it at
CREATE SUBSCRIPTION time.
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Author: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAAKRu_Zqd-e5imT_3-ZiQv1cfsWuy16OJTiUaCvqpq4V7GVdSg@mail.gmail.com
Up to now, the ID values returned by pg_stat_get_backend_idset() and
used by pg_stat_get_backend_activity() and allied functions were just
indexes into a local array of sessions seen by the last stats refresh.
This is problematic for a few reasons. The "ID" of a session can vary
over its existence, which is surprising. Also, while these numbers
often match the "backend ID" used for purposes like temp schema
assignment, that isn't reliably true. We can fairly cheaply switch
things around to make these numbers actually be the sessions' backend
IDs. The added test case illustrates that with this definition, the
temp schema used by a given session can be obtained given its PID.
While here, delete some dead code that guarded against getting
a NULL return from pgstat_fetch_stat_local_beentry(). That can't
happen as long as the caller is careful to pass an in-range array
index, as all the callers are. (This code may not have been dead
when written, but it surely is now.)
Nathan Bossart
Discussion: https://postgr.es/m/20220815205811.GA250990@nathanxps13
Autoconf is showing its age, fewer and fewer contributors know how to wrangle
it. Recursive make has a lot of hard to resolve dependency issues and slow
incremental rebuilds. Our home-grown MSVC build system is hard to maintain for
developers not using Windows and runs tests serially. While these and other
issues could individually be addressed with incremental improvements, together
they seem best addressed by moving to a more modern build system.
After evaluating different build system choices, we chose to use meson, to a
good degree based on the adoption by other open source projects.
We decided that it's more realistic to commit a relatively early version of
the new build system and mature it in tree.
This commit adds an initial version of a meson based build system. It supports
building postgres on at least AIX, FreeBSD, Linux, macOS, NetBSD, OpenBSD,
Solaris and Windows (however only gcc is supported on aix, solaris). For
Windows/MSVC postgres can now be built with ninja (faster, particularly for
incremental builds) and msbuild (supporting the visual studio GUI, but
building slower).
Several aspects (e.g. Windows rc file generation, PGXS compatibility, LLVM
bitcode generation, documentation adjustments) are done in subsequent commits
requiring further review. Other aspects (e.g. not installing test-only
extensions) are not yet addressed.
When building on Windows with msbuild, builds are slower when using a visual
studio version older than 2019, because those versions do not support
MultiToolTask, required by meson for intra-target parallelism.
The plan is to remove the MSVC specific build system in src/tools/msvc soon
after reaching feature parity. However, we're not planning to remove the
autoconf/make build system in the near future. Likely we're going to keep at
least the parts required for PGXS to keep working around until all supported
versions build with meson.
Some initial help for postgres developers is at
https://wiki.postgresql.org/wiki/Meson
With contributions from Thomas Munro, John Naylor, Stone Tickle and others.
Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Author: Peter Eisentraut <peter@eisentraut.org>
Reviewed-By: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/20211012083721.hvixq4pnh2pixr3j@alap3.anarazel.de
So far they were created below CacheMemoryContext. However, that's not
guaranteed to exist in all situations, leading to memory contexts created as
top-level contexts. There isn't actually a good reason anymore to create them
below CacheMemoryContext, so just creating them below TopMemoryContext seems
the best approach.
Reported-by: Reid Thompson <reid.thompson@crunchydata.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Author: "Drouvot, Bertrand" <bdrouvot@amazon.com>
Discussion: https://postgr.es/m/b948b729-42fe-f88c-2f4a-0e65d84c049b@amazon.com
Backpatch: 15-
Somewhere during the development of the patch acquiring a lock during read
access to variable-numbered stats got lost. The missing lock acquisition won't
cause corruption, but can lead to reading torn values when accessing
stats. Add the missing lock acquisitions.
Reported-by: Greg Stark <stark@mit.edu>
Reviewed-by: "Drouvot, Bertrand" <bdrouvot@amazon.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/CAM-w4HMYkM_DkYhWtUGV+qE_rrBxKOzOF0+5faozxO3vXrc9wA@mail.gmail.com
Backpatch: 15-
Previously we displayed "DSMFillZeroWrite" while in posix_fallocate(),
because we shared the same wait event for "mmap" and "posix" DSM types.
Let's introduce a new wait event "DSMAllocate", to be more accurate.
Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220711174518.yldckniicknsxgzl%40awork3.anarazel.de
That comment might have been true at some point during development, but
definitely isn't anymore.
Reported-By: Melanie Plageman <melanieplageman@gmail.com>
Backpatch: 15-
Previously the timer was enabled whenever there were any pending stats after
executing a statement, just to then be disabled again when not idle
anymore. That lead to an increase in GetCurrentTimestamp() calls from within
timeout.c compared to 14.
To avoid that increase, leave the timer enabled until stats are reported,
rather than until idle. The timer is only disabled once the pending stats have
been reported.
For me this fixes the increase in GetCurrentTimestamp() calls, there now are
fewer calls in 15 than in 14, in the previously slowed down workload.
While at it, also update assertion in pgstat_report_stat() to be more precise.
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220616233130.rparivafipt6doj3@alap3.anarazel.de
Backpatch: 15-
Previously we didn't, which lead to an assertion failure when resetting
partially loaded statistics. This was encountered on the buildfarm, for
as-of-yet unknown reasons.
Ttighten up a validity check when reading the stats file, verifying 'E'
signals the end of the file (rather than just stopping reading). That's then
used in a test appending to the stats file that crashed before the fix in
pgstat_drop_all_entries().
Reported by buildfarm animals mylodon and kestrel, via Tom Lane.
Discussion: https://postgr.es/m/1656446.1650043715@sss.pgh.pa.us
When not loading stats at startup (i.e. pgstat_discard_stats() getting
called), reset timestamps of fixed numbered stats would be left at
0. Oversight in 5891c7a8ed.
Instead use pgstat_reset_after_failure() and add tests verifying that
fixed-numbered reset timestamps are set appropriately.
Reported-By: "David G. Johnston" <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/CAKFQuwamFuaQHKdhcMt4Gbw5+Hca2UE741B8gOOXoA=TtAd2Yw@mail.gmail.com
This reverts commits 0147fc7, 4567596, aa64f23, and 5ecd018.
There is no longer agreement that introducing this function
was the right way to address the problem. The consensus now
seems to favor trying to make a correct value for MaxBackends
available to mdules executing their _PG_init() functions.
Nathan Bossart
Discussion: http://postgr.es/m/20220323045229.i23skfscdbvrsuxa@jrouhaud
With nowait passed as false, pgstat_lock_entry() must return true
so there's no need to check its result. Coverity seems unconvinced
of this, so whack it upside the head with a (void) cast.
In the stats collector days it was hard to write tests for the stats system,
because fundamentally delivery of stats messages over UDP was not
synchronous (nor guaranteed). Now we easily can force pending stats updates to
be flushed synchronously.
This moves stats.sql into a parallel group, there isn't a reason for it to run
in isolation anymore. And it may shake out some bugs.
Bumps catversion.
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
Just after committing 5891c7a8ed, a test running with debug_discard_caches=1
failed locally...
pgstat_drop_relation() neither checked pgstat_should_count_relation() nor
called pgstat_prep_relation_pending(). With debug_discard_caches=1
rel->pgstat_info wasn't set up, leading pg_stat_get_xact_tuples_inserted()
spuriously still returning > 0 while in the transaction dropping the table.
Zeroing out an lwlock in a normal build turns out to not trigger any alarms,
if nobody can use the lwlock at that moment (as the case here). But with
--disable-spinlocks --disable-atomics, the sema field needs to be initialized.
We probably should make sure that this fails on more common configurations as
well...
Per buildfarm animal rorqual
Previously the statistics collector received statistics updates via UDP and
shared statistics data by writing them out to temporary files regularly. These
files can reach tens of megabytes and are written out up to twice a
second. This has repeatedly prevented us from adding additional useful
statistics.
Now statistics are stored in shared memory. Statistics for variable-numbered
objects are stored in a dshash hashtable (backed by dynamic shared
memory). Fixed-numbered stats are stored in plain shared memory.
The header for pgstat.c contains an overview of the architecture.
The stats collector is not needed anymore, remove it.
By utilizing the transactional statistics drop infrastructure introduced in a
prior commit statistics entries cannot "leak" anymore. Previously leaked
statistics were dropped by pgstat_vacuum_stat(), called from [auto-]vacuum. On
systems with many small relations pgstat_vacuum_stat() could be quite
expensive.
Now that replicas drop statistics entries for dropped objects, it is not
necessary anymore to reset stats when starting from a cleanly shut down
replica.
Subsequent commits will perform some further code cleanup, adapt docs and add
tests.
Bumps PGSTAT_FILE_FORMAT_ID.
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-By: Andres Freund <andres@anarazel.de>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Reviewed-By: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-By: "David G. Johnston" <david.g.johnston@gmail.com>
Reviewed-By: Tomas Vondra <tomas.vondra@2ndquadrant.com> (in a much earlier version)
Reviewed-By: Arthur Zakirov <a.zakirov@postgrespro.ru> (in a much earlier version)
Reviewed-By: Antonin Houska <ah@cybertec.at> (in a much earlier version)
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
Discussion: https://postgr.es/m/20220308205351.2xcn6k4x5yivcxyd@alap3.anarazel.de
Discussion: https://postgr.es/m/20210319235115.y3wz7hpnnrshdyv6@alap3.anarazel.de
Most of pgstat uses pgstat_<verb>_<subject>() or just <verb>_<subject>(). But
not all (some introduced fairly recently by me). Rename ones that aren't
intentionally following a different scheme (e.g. AtEOXact_*).
Previously the pgstat <-> replication slots API was done with on the basis of
names. However, the upcoming move to storing stats in shared memory makes it
more convenient to use a integer as key.
Change the replication slot functions to take the slot rather than the slot
name, and expose ReplicationSlotIndex() to compute the index of an replication
slot. Special handling will be required for restarts, as the index is not
stable across restarts. For now pgstat internally still uses names.
Rename pgstat_report_replslot_{create,drop}() to
pgstat_{create,drop}_replslot() to match the functions for other kinds of
stats.
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220404041516.cctrvpadhuriawlq@alap3.anarazel.de
One problematic part of the current statistics collector design is that there
is no reliable way of getting rid of statistics entries. Because of that
pgstat_vacuum_stat() (called by [auto-]vacuum) matches all stats for the
current database with the catalog contents and tries to drop now-superfluous
entries. That's quite expensive. What's worse, it doesn't work on physical
replicas, despite physical replicas collection statistics entries.
This commit introduces infrastructure to create / drop statistics entries
transactionally, together with the underlying catalog objects (functions,
relations, subscriptions). pgstat_xact.c maintains a list of stats entries
created / dropped transactionally in the current transaction. To ensure the
removal of statistics entries is durable dropped statistics entries are
included in commit / abort (and prepare) records, which also ensures that
stats entries are dropped on standbys.
Statistics entries created separately from creating the underlying catalog
object (e.g. when stats were previously lost due to an immediate restart)
are *not* WAL logged. However that can only happen outside of the transaction
creating the catalog object, so it does not lead to "leaked" statistics
entries.
For this to work, functions creating / dropping functions / relations /
subscriptions need to call into pgstat. For subscriptions this was already
done when dropping subscriptions, via pgstat_report_subscription_drop() (now
renamed to pgstat_drop_subscription()).
This commit does not actually drop stats yet, it just provides the
infrastructure. It is however a largely independent piece of infrastructure,
so committing it separately makes sense.
Bumps XLOG_PAGE_MAGIC.
Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
With the introduction of PgStat_Kind PgStat_Single_Reset_Type,
PgStat_Shared_Reset_Target don't make sense anymore. Replace them with
PgStat_Kind.
Instead of having dedicated reset functions for different kinds of stats, use
two generic helper routines (one to reset all stats of a kind, one to reset
one stats entry).
A number of reset functions were named pgstat_reset_*_counter(), despite
affecting multiple counters. The generic helper routines get rid of
pgstat_reset_single_counter(), pgstat_reset_subscription_counter().
Rename pgstat_reset_slru_counter(), pgstat_reset_replslot_counter() to
pgstat_reset_slru(), pgstat_reset_replslot() respectively, and have them only
deal with a single SLRU/slot. Resetting all SLRUs/slots goes through the
generic pgstat_reset_of_kind().
Previously pg_stat_reset_replication_slot() used SearchNamedReplicationSlot()
to check if a slot exists. API wise it seems better to move that to
pgstat_replslot.c.
This is done separately from the - quite large - shared memory statistics
patch to make review easier.
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220404041516.cctrvpadhuriawlq@alap3.anarazel.de
Until now index_concurrently_swap() directly modified pgstat internal
datastructures. That will break with the introduction of shared memory
statistics and seems off architecturally.
This is done separately from the - quite large - shared memory statistics
patch to make review easier.
Author: Andres Freund <andres@anarazel.de>
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
Only the pgstat_send_* functions that are called from outside pgstat*.c are
renamed (the rest will go away). This is done separately from the - quite
large - shared memory statistics patch to make review easier.
Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220404041516.cctrvpadhuriawlq@alap3.anarazel.de
Soon the stats collector will be no more, with statistics instead getting
stored in shared memory. There are a lot of references to the stats collector
in comments. This commit replaces most of these references with "cumulative
statistics system", with the remaining ones getting replaced as part of
subsequent commits.
This is done separately from the - quite large - shared memory statistics
patch to make review easier.
Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
Discussion: https://postgr.es/m/20220308205351.2xcn6k4x5yivcxyd@alap3.anarazel.de
The transactional integration code is largely independent from the rest of
pgstat.c. Subsequent commits will add more related code.
Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/20220404041516.cctrvpadhuriawlq@alap3.anarazel.de
Because this strategy logs changes on a block-by-block basis, it
avoids the need to checkpoint before and after the operation.
However, because it logs each changed block individually, it might
generate a lot of extra write-ahead logging if the template database
is large. Therefore, the older strategy remains available via a new
STRATEGY parameter to CREATE DATABASE, and a corresponding --strategy
option to createdb.
Somewhat controversially, this patch assembles the list of relations
to be copied to the new database by reading the pg_class relation of
the template database. Cross-database access like this isn't normally
possible, but it can be made to work here because there can't be any
connections to the database being copied, nor can it contain any
in-doubt transactions. Even so, we have to use lower-level interfaces
than normal, since the table scan and relcache interfaces will not
work for a database to which we're not connected. The advantage of
this approach is that we do not need to rely on the filesystem to
determine what ought to be copied, but instead on PostgreSQL's own
knowledge of the database structure. This avoids, for example,
copying stray files that happen to be located in the source database
directory.
Dilip Kumar, with a fairly large number of cosmetic changes by me.
Reviewed and tested by Ashutosh Sharma, Andres Freund, John Naylor,
Greg Nancarrow, Neha Sharma. Additional feedback from Bruce Momjian,
Heikki Linnakangas, Julien Rouhaud, Adam Brusselback, Kyotaro
Horiguchi, Tomas Vondra, Andrew Dunstan, Álvaro Herrera, and others.
Discussion: http://postgr.es/m/CA+TgmoYtcdxBjLh31DLxUXHxFVMPGzrU5_T=CYCvRyFHywSBUQ@mail.gmail.com
pgstat.c is very long, and it's hard to find an order that makes sense and is
likely to be maintained over time. Splitting the different pieces into
separate files makes that a lot easier.
With a few exceptions, this commit just moves code around. Those exceptions
are:
- adding file headers for new files
- removing 'static' from functions
- adapting pgstat_assert_is_up() to work across TUs
- minor comment adjustments
git diff --color-moved=dimmed-zebra is very helpful separating code movement
from code changes.
The next commit in this series will reorder pgstat.[ch] contents to be a bit
more coherent.
Earlier revisions of this patch had "global" statistics (archiver, bgwriter,
checkpointer, replication slots, SLRU, WAL) in one file, because each seemed
small enough. However later commits will increase their size and their
aggregate size is not insubstantial. It also just seems easier to split each
type of statistic into its own file.
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
If we run out of space in the checkpointer sync request queue (which is
hopefully rare on real systems, but common with very small buffer pool),
we wait for it to drain. While waiting, we should report that as a wait
event so that users know what is going on, and also handle postmaster
death, since otherwise the loop might never terminate if the
checkpointer has exited.
Back-patch to 12. Although the problem exists in earlier releases too,
the code is structured differently before 12 so I haven't gone any
further for now, in the absence of field complaints.
Reported-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220226213942.nb7uvb2pamyu26dj%40alap3.anarazel.de
The checkpointer shouldn't ignore its latch. Other backends may be
waiting for it to drain the request queue. Hopefully real systems don't
have a full queue often, but the condition is reached easily when
shared_buffers is small.
This involves defining a new wait event, which will appear in the
pg_stat_activity view often due to spread checkpoints.
Back-patch only to 14. Even though the problem exists in earlier
branches too, it's hard to hit there. In 14 we stopped using signal
handlers for latches on Linux, *BSD and macOS, which were previously
hiding this problem by interrupting the sleep (though not reliably, as
the signal could arrive before the sleep begins; precisely the problem
latches address).
Reported-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220226213942.nb7uvb2pamyu26dj%40alap3.anarazel.de
Previously, it was really easy to write code that accessed MaxBackends
before we'd actually initialized it, especially when coding up an
extension. To make this less error-prune, introduce a new function
GetMaxBackends() which should be used to obtain the correct value.
This will ERROR if called too early. Demote the global variable to
a file-level static, so that nobody can peak at it directly.
Nathan Bossart. Idea by Andres Freund. Review by Greg Sabino Mullane,
by Michael Paquier (who had doubts about the approach), and by me.
Discussion: http://postgr.es/m/20210802224204.bckcikl45uezv5e4@alap3.anarazel.de
This fixes a set of issues that have accumulated over the past months
(or years) in various code areas. Most fixes are related to some recent
additions, as of the development of v15.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20220124030001.GQ23027@telsasoft.com
pg_basebackup now has a --target=TARGET[:DETAIL] option. If specfied,
it is sent to the server as the value of the TARGET option to the
BASE_BACKUP command. If DETAIL is included, it is sent as the value of
the new TARGET_DETAIL option to the BASE_BACKUP command. If the
target is anything other than 'client', pg_basebackup assumes that it
will now be the server's job to write the backup in a location somehow
defined by the target, and that it therefore needs to write nothing
locally. However, the server will still send messages to the client
for progress reporting purposes.
On the server side, we now support two additional types of backup
targets. There is a 'blackhole' target, which just throws away the
backup data without doing anything at all with it. Naturally, this
should only be used for testing and debugging purposes, since you will
not actually have a backup when it finishes running. More usefully,
there is also a 'server' target, so you can now use something like
'pg_basebackup -Xnone -t server:/SOME/PATH' to write a backup to some
location on the server. We can extend this to more types of targets
in the future, and might even want to create an extensibility
mechanism for adding new target types.
Since WAL fetching is handled with separate client-side logic, it's
not part of this mechanism; thus, backups with non-default targets
must use -Xnone or -Xfetch.
Patch by me, with a bug fix by Jeevan Ladhe. The patch set of which
this is a part has also had review and/or testing from Tushar Ahuja,
Suraj Kharage, Dipesh Pandit, and Mark Dilger.
Discussion: http://postgr.es/m/CA+TgmoaYZbz0=Yk797aOJwkGJC-LK3iXn+wzzMx7KdwNpZhS5g@mail.gmail.com
Session statistics, as introduced by 960869da08, had several shortcomings:
- an additional GetCurrentTimestamp() call that also impaired the accuracy of
the data collected
This can be avoided by passing the current timestamp we already have in
pgstat_report_stat().
- an additional statistics UDP packet sent every 500ms
This is solved by adding the new statistics to PgStat_MsgTabstat.
This is conceptually ugly, because session statistics are not
table statistics. But the struct already contains data unrelated
to tables, so there is not much damage done.
Connection and disconnection are reported in separate messages, which
reduces the number of additional messages to two messages per session and a
slight increase in PgStat_MsgTabstat size (but the same number of table
stats fit).
- Session time computation could overflow on systems where long is 32 bit.
Reported-By: Andres Freund <andres@anarazel.de>
Author: Andres Freund <andres@anarazel.de>
Author: Laurenz Albe <laurenz.albe@cybertec.at>
Discussion: https://postgr.es/m/20210801205501.nyxzxoelqoo4x2qc%40alap3.anarazel.de
Backpatch: 14-, where the feature was introduced.
Previously log messages late during shutdown could end up using either another
backend's PgBackendStatus (multi user) or segfault (single user) because
pgstat_get_my_query_id()'s check for !MyBEEntry didn't filter out use after
pgstat_beshutdown_hook().
This became a bug in 4f0b0966c8, but was a bit fishy before. But given
there's no known problematic cases before 14, it doesn't seem worth
backpatching further.
Also fixes a wrong filename in a comment, introduced in e1025044.
Reported-By: Andres Freund <andres@anarazel.de>
Reviewed-By: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://postgr.es/m/Julien Rouhaud <rjuju123@gmail.com>
Backpatch: 14-
This has the advantage to make a process more responsive when the
postmaster dies, even if the wait time was rather limited as there was
only a 50ms timeout here. Another advantage of this change is for
monitoring, as we gain a new wait event for the end-of-vacuum
truncation.
Author: Bharath Rupireddy
Reviewed-by: Aleksander Alekseev, Thomas Munro, Michael Paquier
Discussion: https://postgr.es/m/CALj2ACU4AdPCq6NLfcA-ZGwX7pPCK5FgEj-CAU0xCKzkASSy_A@mail.gmail.com
Also "make reformat-dat-files".
The only change worthy of note is that pgindent messed up the formatting
of launcher.c's struct LogicalRepWorkerId, which led me to notice that
that struct wasn't used at all anymore, so I just took it out.
log_statement is issued before query_id can be computed, so properly
clear the value, and document the interaction.
Reported-by: Fujii Masao, Michael Paquier
Discussion: https://postgr.es/m/YHPkU8hFi4no4NSw@paquier.xyz
Author: Julien Rouhaud
Previously, it was pg_stat_activity.queryid to match the
pg_stat_statements queryid column. This is an adjustment to patch
4f0b0966c8. This also adjusts some of the internal function calls to
match. Catversion bumped.
Reported-by: Álvaro Herrera, Julien Rouhaud
Discussion: https://postgr.es/m/20210408032704.GA7498@alvherre.pgsql
This adds a function, pg_wait_for_backend_termination(), and a new
timeout argument to pg_terminate_backend(), which will wait for the
backend to actually terminate (with or without signaling it to do so
depending on which function is called). The default behaviour of
pg_terminate_backend() remains being timeout=0 which does not waiting.
For pg_wait_for_backend_termination() the default wait is 5 seconds.
Author: Bharath Rupireddy
Reviewed-By: Fujii Masao, David Johnston, Muhammad Usama,
Hou Zhijie, Magnus Hagander
Discussion: https://postgr.es/m/CALj2ACUBpunmyhYZw-kXCYs5NM+h6oG_7Df_Tn4mLmmUQifkqA@mail.gmail.com
Use the in-core query id computation for pg_stat_activity,
log_line_prefix, and EXPLAIN VERBOSE.
Similar to other fields in pg_stat_activity, only the queryid from the
top level statements are exposed, and if the backends status isn't
active then the queryid from the last executed statements is displayed.
Add a %Q placeholder to include the queryid in log_line_prefix, which
will also only expose top level statements.
For EXPLAIN VERBOSE, if a query identifier has been computed, either by
enabling compute_query_id or using a third-party module, display it.
Bump catalog version.
Discussion: https://postgr.es/m/20210407125726.tkvjdbw76hxnpwfi@nol
Author: Julien Rouhaud
Reviewed-by: Alvaro Herrera, Nitin Jadhav, Zhihong Yu
Michael Paquier
Masahiko Sawada
Andres Freund
Bruce Momjian
Tom Lane
Peter Geoghegan
Stephen Frost
Thomas Munro
Amit Kapila
Andrew Dunstan
John Naylor
Robert Haas
David Rowley
Peter Eisentraut
Alvaro Herrera
Fujii Masao
Magnus Hagander