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author | Andres Freund <andres@anarazel.de> | 2022-04-06 21:29:46 -0700 |
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committer | Andres Freund <andres@anarazel.de> | 2022-04-06 21:29:46 -0700 |
commit | 5891c7a8ed8f2d3d577e7eea34dacff12d7b6bbd (patch) | |
tree | 909f20fa511d5fde6463c58403bb82508c35cfab /src/backend/tcop | |
parent | be902e26510788c70a874ea54bad753b723d018f (diff) | |
download | postgresql-5891c7a8ed8f2d3d577e7eea34dacff12d7b6bbd.tar.gz |
pgstat: store statistics in shared memory.
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
Diffstat (limited to 'src/backend/tcop')
-rw-r--r-- | src/backend/tcop/postgres.c | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c index 260b650f15..95dc2e2c83 100644 --- a/src/backend/tcop/postgres.c +++ b/src/backend/tcop/postgres.c @@ -3372,6 +3372,14 @@ ProcessInterrupts(void) IdleSessionTimeoutPending = false; } + if (IdleStatsUpdateTimeoutPending) + { + /* timer should have been disarmed */ + Assert(!IsTransactionBlock()); + IdleStatsUpdateTimeoutPending = false; + pgstat_report_stat(true); + } + if (ProcSignalBarrierPending) ProcessProcSignalBarrier(); @@ -4044,6 +4052,7 @@ PostgresMain(const char *dbname, const char *username) volatile bool send_ready_for_query = true; bool idle_in_transaction_timeout_enabled = false; bool idle_session_timeout_enabled = false; + bool idle_stats_update_timeout_enabled = false; AssertArg(dbname != NULL); AssertArg(username != NULL); @@ -4407,6 +4416,8 @@ PostgresMain(const char *dbname, const char *username) } else { + long stats_timeout; + /* * Process incoming notifies (including self-notifies), if * any, and send relevant messages to the client. Doing it @@ -4417,7 +4428,14 @@ PostgresMain(const char *dbname, const char *username) if (notifyInterruptPending) ProcessNotifyInterrupt(false); - pgstat_report_stat(false); + /* Start the idle-stats-update timer */ + stats_timeout = pgstat_report_stat(false); + if (stats_timeout > 0) + { + idle_stats_update_timeout_enabled = true; + enable_timeout_after(IDLE_STATS_UPDATE_TIMEOUT, + stats_timeout); + } set_ps_display("idle"); pgstat_report_activity(STATE_IDLE, NULL); @@ -4452,9 +4470,9 @@ PostgresMain(const char *dbname, const char *username) firstchar = ReadCommand(&input_message); /* - * (4) turn off the idle-in-transaction and idle-session timeouts, if - * active. We do this before step (5) so that any last-moment timeout - * is certain to be detected in step (5). + * (4) turn off the idle-in-transaction, idle-session and + * idle-stats-update timeouts if active. We do this before step (5) so + * that any last-moment timeout is certain to be detected in step (5). * * At most one of these timeouts will be active, so there's no need to * worry about combining the timeout.c calls into one. @@ -4469,6 +4487,11 @@ PostgresMain(const char *dbname, const char *username) disable_timeout(IDLE_SESSION_TIMEOUT, false); idle_session_timeout_enabled = false; } + if (idle_stats_update_timeout_enabled) + { + disable_timeout(IDLE_STATS_UPDATE_TIMEOUT, false); + idle_stats_update_timeout_enabled = false; + } /* * (5) disable async signal conditions again. |