Horton

Re: shared-memory based stats collector

Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>

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From: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
To: tomas.vondra@2ndquadrant.com
Cc: alvherre@2ndquadrant.com, andres@anarazel.de, ah@cybertec.at, magnus@hagander.net, robertmhaas@gmail.com, tgl@sss.pgh.pa.us, pgsql-hackers@postgresql.org
Date: 2018-11-12T11:10:42Z
Lists: pgsql-hackers

Attachments

At Fri, 9 Nov 2018 14:16:31 +0100, Tomas Vondra <tomas.vondra@2ndquadrant.com> wrote in <803f2d96-3b4b-f357-9a2e-45443212f13d@2ndquadrant.com>
> 
> 
> On 11/9/18 9:33 AM, Kyotaro HORIGUCHI wrote:
> > Hello. This is rebased version.
> > At Thu, 8 Nov 2018 16:06:49 +0100, Tomas Vondra
> > <tomas.vondra@2ndquadrant.com> wrote in
> > <de249c3f-79c9-b75c-79a3-5e2d008548a8@2ndquadrant.com>
> >> However a quite a few extensions in contrib seem are broken now. It
> >> seems fixing it is as simple as including the new bestatus.h next to
> >> pgstat.h.
> > The additional 0009 does that.
> > 
> 
> That does fix it, indeed. But the break happens in 0003, so that's
> where the fixes should be moved - I've tried to simply apply 0009
> right after 0003, but that does not seem to work because bestatus.h
> does not exist at that point yet :-/

Sorry, I misunderstood you. The real reason for breaking 0003 as
you saw was the result I just removed PG_STAT_TMP_DIR. 0005 fixes
that later. I (half-intentionally) didin't keep soundness of the
source tree at v8-0003 and v8-0008.

> The current split into 8 parts seems quite sensible to me, i.e. that's
> how it might get committed eventually. That however means each part
> needs to be correct on it's own (hence fixes in 0009 are a problem).

Thanks. I neatended up the patchset so that individual patch
keeps source buildable and doesn't break programs' behaviors.

v9-0001-sequential-scan-for-dshash.patch
v9-0002-Add-conditional-lock-feature-to-dshash.patch
  same to v8

v9-0003-Make-archiver-process-an-auxiliary-process.patch
  moved from v8-0004 since this is applicable independently from
  v8-0003.

v9-0004-Shared-memory-based-stats-collector.patch
  v8-0003 + some fixes to make contribs work and removed initdb
  part.

v9-0005-Remove-statistics-temporary-directory.patch
  v8-0005 + v8-0006 + initdb part of v8-0003. pg_stat_statements
  may still need fix since I changed only the directory for
  temporary query files.

v9-0006-Split-out-backend-status-monitor-part-from-pgstat.patch
  v8-0008 plus v8-0009

v9-0007-Documentation-update.patch
  this still leaves description about UDP-based stats collector
  and will need further edit.

 regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center

Commits

  1. Improve comment about dropped entries in pgstat.c

  2. Fix temporary memory leak in system table index scans

  3. pgstat: set timestamps of fixed-numbered stats after a crash.

  4. pgstat: Update docs to match the shared memory stats reality.

  5. pgstat: Hide instability in stats.spec with -DCATCACHE_FORCE_RELEASE.

  6. pgstat: add/extend tests for resetting various kinds of stats.

  7. Add minimal tests for recovery conflict handling.

  8. pgstat: test stats interactions with physical replication.

  9. pgstat: add tests for handling of restarts, including crashes.

  10. pgstat: add tests for transaction behaviour, 2PC, function stats.

  11. pgstat: add pg_stat_have_stats() test helper.

  12. pgstat: add pg_stat_force_next_flush(), use it to simplify tests.

  13. pgstat: move pgstat.c to utils/activity.

  14. pgstat: store statistics in shared memory.

  15. pgstat: remove stats_temp_directory.

  16. pgstat: rename STATS_COLLECTOR GUC group to STATS_CUMULATIVE.

  17. pgstat: revise replication slot API in preparation for shared memory stats.

  18. pgstat: scaffolding for transactional stats creation / drop.

  19. pgstat: introduce PgStat_Kind enum.

  20. pgstat: prepare APIs used by pgstatfuncs for shared memory stats.

  21. pgstat: add pgstat_copy_relation_stats().

  22. pgstat: rename some pgstat_send_* functions to pgstat_report_*.

  23. pgstat: stats collector references in comments.

  24. pgstat: move transactional code into pgstat_xact.c.

  25. dsm: allow use in single user mode.

  26. dshash: revise sequential scan support.

  27. pgstat: remove some superflous comments from pgstat.h.

  28. pgstat: reorder pgstat.[ch] contents.

  29. pgstat: split different types of stats into separate files.

  30. pgstat: introduce pgstat_relation_should_count().

  31. pgstat: separate "xact level" handling out of relation specific functions.

  32. pgstat: rename pgstat_initstats() to pgstat_relation_init().

  33. pgstat: split out WAL handling from pgstat_{initialize,report_stat}.

  34. pgstat: run pgindent on pgstat.c/h.

  35. pgstat: split relation, database handling out of pgstat_report_stat().

  36. Move code around in StartupXLOG().

  37. pgstat: Prepare to use mechanism for truncated rels also for droppped rels.

  38. pgstat: Split out relation stats handling from AtEO[Sub]Xact_PgStat() etc.

  39. pgstat: Schedule per-backend pgstat shutdown via before_shmem_exit().

  40. Schedule ShutdownXLOG() in single user mode using before_shmem_exit().

  41. Make parallel worker shutdown complete entirely via before_shmem_exit().

  42. pgstat: Bring up pgstat in BaseInit() to fix uninitialized use of pgstat by AV.

  43. pgstat: split reporting/fetching of bgwriter and checkpointer stats.

  44. Split backend status and progress related functionality out of pgstat.c.

  45. Split wait event related code from pgstat.[ch] into wait_event.[ch].

  46. Make archiver process an auxiliary process.

  47. Force to send remaining WAL stats to the stats collector at walwriter exit.

  48. Add pg_stat_database counters for sessions and session time

  49. Collect statistics about SLRU caches

  50. Don't run atexit callbacks in quickdie signal handlers.

  51. Create a "fast path" for acquiring weak relation locks.