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path: root/src/backend/utils/activity/pgstat_checkpointer.c
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* Update copyright for 2025Bruce Momjian2025-01-01
| | | | Backpatch-through: 13
* Add pg_memory_is_all_zeros() in memutils.hMichael Paquier2024-11-01
| | | | | | | | | | | | | | | | | This new function tests if a memory region starting at a given location for a defined length is made only of zeroes. This unifies in a single path the all-zero checks that were happening in a couple of places of the backend code: - For pgstats entries of relation, checkpointer and bgwriter, where some "all_zeroes" variables were previously used with memcpy(). - For all-zero buffer pages in PageIsVerifiedExtended(). This new function uses the same forward scan as the check for all-zero buffer pages, applying it to the three pgstats paths mentioned above. Author: Bertrand Drouvot Reviewed-by: Peter Eisentraut, Heikki Linnakangas, Peter Smith Discussion: https://postgr.es/m/ZupUDDyf1hHI4ibn@ip-10-97-1-34.eu-west-3.compute.internal
* Fix inconsistent reporting of checkpointer stats.Fujii Masao2024-10-02
| | | | | | | | | | | | | | | | | | | | | | | Previously, the pg_stat_checkpointer view and the checkpoint completion log message could show different numbers for buffers written during checkpoints. The view only counted shared buffers, while the log message included both shared and SLRU buffers, causing inconsistencies. This commit resolves the issue by updating both the view and the log message to separately report shared and SLRU buffers written during checkpoints. A new slru_written column is added to the pg_stat_checkpointer view to track SLRU buffers, while the existing buffers_written column now tracks only shared buffers. This change would help users distinguish between the two types of buffers, in the pg_stat_checkpointer view and the checkpoint complete log message, respectively. Bump catalog version. Author: Nitin Jadhav Reviewed-by: Bharath Rupireddy, Michael Paquier, Kyotaro Horiguchi, Robert Haas Reviewed-by: Andres Freund, vignesh C, Fujii Masao Discussion: https://postgr.es/m/CAMm1aWb18EpT0whJrjG+-nyhNouXET6ZUw0pNYYAe+NezpvsAA@mail.gmail.com
* Add num_done counter to the pg_stat_checkpointer view.Fujii Masao2024-09-30
| | | | | | | | | | | | | | | Checkpoints can be skipped when the server is idle. The existing num_timed and num_requested counters in pg_stat_checkpointer track both completed and skipped checkpoints, but there was no way to count only the completed ones. This commit introduces the num_done counter, which tracks only completed checkpoints, making it easier to see how many were actually performed. Bump catalog version. Author: Anton A. Melnikov Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/9ea77f40-818d-4841-9dee-158ac8f6e690@oss.nttdata.com
* Add PgStat_KindInfo.init_shmem_cbMichael Paquier2024-07-11
| | | | | | | | | | | | | | This new callback gives fixed-numbered stats the possibility to take actions based on the area of shared memory allocated for them. This removes from pgstat_shmem.c any knowledge specific to the types of fixed-numbered stats, and the initializations happen in their own files. Like b68b29bc8fec, this change is useful to make this area of the code more pluggable, so as custom fixed-numbered stats can take actions after their shared memory area is initialized. Reviewed-by: Bertrand Drouvot Discussion: https://postgr.es/m/Zot5bxoPYdS7yaoy@paquier.xyz
* Update copyright for 2024Bruce Momjian2024-01-03
| | | | | | | | Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
* Enhance checkpointer restartpoint statisticsAlexander Korotkov2023-12-25
| | | | | | | | | | | | | | | | | | | | | | | | Bhis commit introduces enhancements to the pg_stat_checkpointer view by adding three new columns: restartpoints_timed, restartpoints_req, and restartpoints_done. These additions aim to improve the visibility and monitoring of restartpoint processes on replicas. Previously, it was challenging to differentiate between successful and failed restartpoint requests. This limitation arises because restartpoints on replicas are dependent on checkpoint records from the primary, and cannot occur more frequently than these checkpoints. The new columns allow for clear distinction and tracking of restartpoint requests, their triggers, and successful completions. This enhancement aids database administrators and developers in better understanding and diagnosing issues related to restartpoint behavior, particularly in scenarios where restartpoint requests may fail. System catalog is changed. Catversion is bumped. Discussion: https://postgr.es/m/99b2ccd1-a77a-962a-0837-191cdf56c2b9%40inbox.ru Author: Anton A. Melnikov Reviewed-by: Kyotaro Horiguchi, Alexander Korotkov
* Introduce pg_stat_checkpointerMichael Paquier2023-10-30
| | | | | | | | | | | | | | | | | | | | | | | | Historically, the statistics of the checkpointer have been always part of pg_stat_bgwriter. This commit removes a few columns from pg_stat_bgwriter, and introduces pg_stat_checkpointer with equivalent, renamed columns (plus a new one for the reset timestamp): - checkpoints_timed -> num_timed - checkpoints_req -> num_requested - checkpoint_write_time -> write_time - checkpoint_sync_time -> sync_time - buffers_checkpoint -> buffers_written The fields of PgStat_CheckpointerStats and its SQL functions are renamed to match with the new field names, for consistency. Note that background writer and checkpointer have been split into two different processes in commits 806a2aee3791 and bf405ba8e460. The pgstat structures were already split, making this change straight-forward. Bump catalog version. Author: Bharath Rupireddy Reviewed-by: Bertrand Drouvot, Andres Freund, Michael Paquier Discussion: https://postgr.es/m/CALj2ACVxX2ii=66RypXRweZe2EsBRiPMj0aHfRfHUeXJcC7kHg@mail.gmail.com
* Remove buffers_backend and buffers_backend_fsync from pg_stat_checkpointerMichael Paquier2023-10-27
| | | | | | | | | | | | | | | | | | | | | | | Two attributes related to checkpointer statistics are removed in this commit: - buffers_backend, that counts the number of buffers written directly by a backend. - buffers_backend_fsync, that counts the number of times a backend had to do fsync() by its own. These are actually not checkpointer properties but backend properties. Also, pg_stat_io provides a more accurate and equivalent report of these numbers, by tracking all the I/O stats related to backends, including writes and fsyncs, so storing them in pg_stat_checkpointer was redundant. Thanks also to Robert Haas and Amit Kapila for their input. Bump catalog version. Author: Bharath Rupireddy Reviewed-by: Bertrand Drouvot, Andres Freund Discussion: https://postgr.es/m/20230210004604.mcszbscsqs3bc5nx@awork3.anarazel.de
* pgstat: Infrastructure for more detailed IO statisticsAndres Freund2023-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Update copyright for 2023Bruce Momjian2023-01-02
| | | | Backpatch-through: 11
* pgstat: store statistics in shared memory.Andres Freund2022-04-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* pgstat: rename some pgstat_send_* functions to pgstat_report_*.Andres Freund2022-04-06
| | | | | | | | | | 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
* pgstat: stats collector references in comments.Andres Freund2022-04-06
| | | | | | | | | | | | | | | | | | 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
* pgstat: consistent function comment formatting.Andres Freund2022-04-04
| | | | | | | | | | | There was a wild mishmash of function comment formatting in pgstat, making it hard to know what to use for any new function and hard to extend existing comments (particularly due to randomly different forms of indentation). Author: Andres Freund <andres@anarazel.de> Reviewed-By: Thomas Munro <thomas.munro@gmail.com> Discussion: https://postgr.es/m/20220329191727.mzzwbl7udhpq7pmf@alap3.anarazel.de Discussion: https://postgr.es/m/20220308205351.2xcn6k4x5yivcxyd@alap3.anarazel.de
* pgstat: split different types of stats into separate files.Andres Freund2022-03-21
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