Re: shared-memory based stats collector

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

From: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
To: tomas.vondra@2ndquadrant.com
Cc: andres@anarazel.de, ah@cybertec.at, magnus@hagander.net, robertmhaas@gmail.com, tgl@sss.pgh.pa.us, pgsql-hackers@postgresql.org
Date: 2018-11-07T00:31:36Z
Lists: pgsql-hackers
Thank you for the comments, Antonin, Tomas.

At Tue, 30 Oct 2018 13:35:23 +0100, Tomas Vondra <tomas.vondra@2ndquadrant.com> wrote in <b38591e0-54ca-7a27-813b-0bf91a204c5b@2ndquadrant.com>
> 
> 
> On 10/05/2018 10:30 AM, Kyotaro HORIGUCHI wrote:
> > Hello.
> > 
> > At Tue, 02 Oct 2018 16:06:51 +0900 (Tokyo Standard Time), Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp> wrote in <20181002.160651.117284090.horiguchi.kyotaro@lab.ntt.co.jp>
> >> It doesn't work nor even compile since I failed to include some
> >> changes. The atached v6-0008 at least compiles and words.
> >>
> >> 0001-0007 are not attached since they are still aplicable on
> >> master head with offsets.
> > 
> > In this patchset 0001-0007 are still the same with the previous
> > version. I'll reorganize the whole patchset in the next version.
> > 
> > This is more saner version of previous v5-0008, which didn't pass
> > regression test. v6-0008 to v6-0010 are attached and they are
> > applied on top of v5-0001-0007.
> > 
> 
> BTW one more thing - I strongly recommend always attaching the whole
> patch series, even if some of the parts did not change.
> 
> Firstly, it makes the reviewer's life much easier, because it's not
> necessary to hunt through past messages for all the bits and resolve
> potential conflicts (e.g. there are two 0008 in recent messages).
> 
> Secondly, it makes http://commitfest.cputube.org/ work - it tries to
> apply patches from a single message, which fails when some of the parts
> are omitted.

Yeah, I know about the second point. About the second point, I'm
not sure which makes review easier confirming difference in all
files or finding not-modified portion from upthread. But ok, I'l
follow your suggestion. I'll attach the whole patches and add
note about difference.

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.