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
Amit Kapila
Andres Freund
Bruce Momjian
Andrew Dunstan
John Naylor
Robert Haas
Michael Paquier
David Rowley
Peter Eisentraut
Tom Lane
Thomas Munro
Alvaro Herrera