Hi,
On Sat, Jan 17, 2026 at 5:20 AM Masahiko Sawada <[email protected]> wrote:
>
> Looking at AutoVacuumReserveParallelWorkers(), it seems that we don't
> check the av_maxParallelWorkers() there. Is it possible that two more
> workers would be reserved even while the existing 2 workers are
> running?
>
> /* Provide as many workers as we can. */
> *nworkers = Min(AutoVacuumShmem->av_freeParallelWorkers, *nworkers);
> AutoVacuumShmem->av_freeParallelWorkers -= *nworkers;
>
OK, I got it. You are right. I'll use the formula that you mentioned in the
previous letter. I'll also add a test for it.
>
> + /* Release all the reserved parallel workers for autovacuum */
> + if (AmAutoVacuumWorkerProcess() && pvs->pcxt->nworkers_launched > 0)
> + AutoVacuumReleaseParallelWorkers(pvs->pcxt->nworkers_launched);
>
> Since we want to release all reserved workers here, I think it's clear
> if we use AutoVacuumReleaseAllParallelWorkers() and we add
> Assert(av_nworkers_reserved == 0) at the end of
> AutoVacuumReleaseAllParallelWorkers(). This way, we can ensure that
> all workers are released and it makes the codes more readable. What do
> you think?
>
Agree that this will be more clear for the readers.
> I've attached the patch proposing this change (please find
> v19-0001_masahiko.patch).
Thank you, I'll apply this patch. A few things in the patch that I changed :
1)
+ * The caller must call AutoVacuumReleaseParallelWorkers() to release the...
I think that we also should mention AutoVacuumReleaseAllParallelWorkers.
2)
+ * Similar to AutoVacuumReleaseParallelWorkers(), but this function releases...
If you don't mind, I'll leave the "same as above" formulation since this is
typical for the postgres code.
>
> +#autovacuum_max_parallel_workers = 2 # disabled by default and limited by
> + # max_worker_processes
>
> It's odd to me that the comment says it's disabled by default while
> being set to 2. I think we can rewrite the comment to:
>
> +#autovacuum_max_parallel_workers = 2 # limited by max_worker_processes
>
Good catch. I forgot to change this comment.
> BTW it seems to me that this GUC should be capped by
> max_parallel_workers instead of max_worker_processes, no?
>
I explained my point about it here [1] and here [2]. What do you think?
> ---
> + long_desc => 'This parameter is capped by "max_worker_processes"
> (not by "autovacuum_max_workers"!).',
>
> I'm concerned that this kind of description might not be appropriate
> to the description in long_desc. Looking at long_desc contents of
> other GUC parameters, we describe the detail of the parameters (e.g.,
> "0 means xxx" or detailed explanation of the effect). Probably we can
> remove this line.
>
Agree.
> >
> > Previously I used the NULL value of this pointer as a flag that we don't
> > need
> > to log workers usage. Now I'll add boolean flag for this purpose (IIUC,
> > "nplanned > 0" condition is not enough to determine whether we should log
> > workers usage, because VACUUM PARALLEL can be called without VERBOSE).
>
> Can't we simply not report the worker usage if nplanned is 0?
>
> >
> > As I wrote above - we don't need to log workers usage if the VERBOSE option
> > is not specified (even if nplanned > 0). Am I missing something?
>
> No. My point is that even when the VERBOSE option is specified, we can
> skip reporting the worker usage if the parallel vacuum is not even
> planned. That is, I think we can do like:
>
> if (vacrel->workers_usage.nplanned > 0)
> appendStringInfo(&buf,
> _("parallel index vacuum/cleanup: %d workers
> were planned and %d workers were launched in total\n"),
> vacrel->workers_usage.nplanned,
> vacrel->workers_usage.nlaunched);
>
Sorry, I forgot that we accumulate the messages for logging only if
"instrument == true". It will cut off the case when manual vacuum is
called without the VERBOSE option.
>
> Thank you for updating the patch. I think that we need the explanation
> of what nlaunched and nplanned actually mean in the PVWorkersUsage
> definition
>
> +typedef struct PVWorkersUsage
> +{
> + int nlaunched;
> + int nplanned;
> +} PVWorkersUsage;
>
> I'm concerned that readers might be confused that nplanned is not the
> number of parallel workers we actually planned to launch.
>
> Or it might make sense to track these three values: planned, reserved,
> and launched. For example, suppose max_worker_processes = 10 and
> autovacuum_max_parallel_workers = 5, if two autovacuum workers try to
> reserve 3 workers each, one worker can reserve and launch 3 and
> another worker can reserve and launch 2. The autovacuum logs would be
> "3 planned and 3 launched" and "3 planned and 2 launched". Users can
> deal with the shortage of parallel workers by increasing
> autovacuum_max_parallel_workers. On the other hand, if some bgworkers
> are being used by other components (.e.g, parallel queries, logical
> replication etc.) and there are only 2 free bgworkers, the autovacuum
> worker can reserve 3 but can launch only 2, and other worker can
> reserve 2 but cannot launch any workers. The autovacuum logs would be
> "3 planned and 2 launched" and "3 planned and 0 launched". Here
> increasing autovacuum_max_parallel_workers resolves the shortage of
> parallel workers, but users would have to increase
> max_worker_processes instead. If we can report the worker usage like
> "3 planned, 3 reserved, and 2 launched" and "3 planned, 2 reserved,
> and 0 launched", users would realize the need to increase
> max_worker_processes. Of course, the "xxx reserved" information would
> not be necessary for VACUUM VERBOSE logs.
>
Hm, I think that reporting of "nreserved" would make it easier for the user to
understand what is going on. Thanks for the detailed explanation, I'll
implement it.
> >
> > We already have such check inside the "fix_cost_based" function :
> > /* Check whether we are running parallel autovacuum */
> > if (pv_shared_cost_params == NULL)
> > return false;
> >
> > We also have this comment:
> > * If we are autovacuum parallel worker, check whether cost-based
> > * parameters had changed in leader worker.
> >
> > As an alternative, I'll add comment explicitly saying that process will
> > immediately return if it not parallel autovacuum participant.
>
> Why don't we add IsInParallelMode() or IsParallelWorker() check before
> calling parallel_vacuum_update_shared_delay_params()?
Considering your suggestion below, I will add this check.
>
> +bool
> +parallel_vacuum_update_shared_delay_params(void)
> +{
> + /* Check whether we are running parallel autovacuum */
> + if (pv_shared_cost_params == NULL)
> + return false;
> +
> + Assert(IsParallelWorker() && !AmAutoVacuumWorkerProcess());
>
> These codes are a bit odd to me in two points:
>
> 1. A process can never be both a parallel worker and an autovacuum worker.
>
> 2. If pv_shared_cost_parame == NULL, even autovacuum workers and
> non-parallel workers can call this function, but it seems to be
> unexpected function call given the subsequent assertion. If we want to
> have an assertion to ensure that a function is called only by
> processes we expect or allow, I think we should add an assertion to
> the beginning of function. How about rewriting these parts to:
>
> Assert(IsParallelWorker());
>
> /* Check whether we are running parallel autovacuum */
> if (pv_shared_cost_params == NULL)
> return false;
>
Agree, it will be much more clear.
> ---
> + * Note, that this function has no effect if we are non-autovacuum
> + * parallel worker.
> + */
>
> I don't think this kind of comment should be noted here since if we
> change the parallel_vacuum_update_shared_delay_params() behavior in
> the future, such comments would get easily out-of-sync.
>
If behavior will be changed, then all comments for this function will need to
be changed, actually. Don't get me wrong - I just think that this Note is
important for the readers. But if you doubt its usefulness, I don't
mind deleting it.
> > > IIUC autovacuum parallel workers seems to update their
> > > vacuum_cost_{delay|limit} every vacuum_delay_point(), which seems not
> > > good. Can we somehow avoid unnecessary updates?
> >
> > More precisely, parallel worker *reads* leader's parameters every
> > delay_point.
> > Obviously, this does not mean that the parameters will necessarily be
> > updated.
> >
> > But I don't see anything wrong with this logic. We just every time get the
> > most
> > relevant parameters from the leader. Of course we can introduce some
> > signaling mechanism, but it will have the same effect as in the current
> > code.
>
> Although the parameter propagation itself is working correctly, the
> current implementation seems suboptimal performance-wise. Acquiring an
> additional spinlock and updating the local variables for every block
> seems too costly to me. IIUC we would end up incurring these costs
> even when vacuum delays are disabled. I think we need to find a better
> way.
>
> For example, we can have a generation of these parameters. That is,
> the leader increments the generation (stored in PVSharedCostParams)
> whenever updating them after reloading the configuration file, and
> workers maintain its generation of the parameters currently used. If
> the worker's generation < the global generation, it updates its
> parameters along with its generation. I think we can implement the
> generation using pg_atomic_u32, making the check for parameter updates
> lock-free. There might be better ideas, though.
>
OK, I see your point. Considering that we need to check some shared state (in
order to understand whether we should update our params), an atomic variable
seem to be the best solution.
Thank you for the review! Please, see v20 patches. Main changes :
1) Add new formula for freeParallelWorkers computation
2) Add 'nreserved' logging for parallel autovacuum
3) Add atomic variable to speed up checking shared params state change
4) New test for autovacuum_max_parallel_workers parameter change
5) Fully get rid of "custom" injection points in tests
BTW, I think that we need more fixes for documentation, so I'll
take a look at it in the near future.
[1]
https://www.postgresql.org/message-id/CAJDiXgiYiX%2BazuR76DcVx8fZn57m_4v6cB14-GW34mWa%3DqudFQ%40mail.gmail.com
[2]
https://www.postgresql.org/message-id/CAJDiXgjX%2BbO%3DdEZxpnsh588N3BsQ%3D7MHX3YQSJS6FxqGq4zMqQ%40mail.gmail.com
--
Best regards,
Daniil Davydov
From 8312e2a35fd070876f91e7e9555a46e6a71d56e6 Mon Sep 17 00:00:00 2001
From: Daniil Davidov <[email protected]>
Date: Sun, 23 Nov 2025 02:32:44 +0700
Subject: [PATCH v20 5/5] Documentation for parallel autovacuum
---
doc/src/sgml/config.sgml | 17 +++++++++++++++++
doc/src/sgml/maintenance.sgml | 12 ++++++++++++
doc/src/sgml/ref/create_table.sgml | 20 ++++++++++++++++++++
3 files changed, 49 insertions(+)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 0fad34da6eb..c64897f4707 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -2849,6 +2849,7 @@ include_dir 'conf.d'
<para>
When changing this value, consider also adjusting
<xref linkend="guc-max-parallel-workers"/>,
+ <xref linkend="guc-autovacuum-max-parallel-workers"/>,
<xref linkend="guc-max-parallel-maintenance-workers"/>, and
<xref linkend="guc-max-parallel-workers-per-gather"/>.
</para>
@@ -9284,6 +9285,22 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
</listitem>
</varlistentry>
+ <varlistentry id="guc-autovacuum-max-parallel-workers" xreflabel="autovacuum_max_parallel_workers">
+ <term><varname>autovacuum_max_parallel_workers</varname> (<type>integer</type>)
+ <indexterm>
+ <primary><varname>autovacuum_max_parallel_workers</varname></primary>
+ <secondary>configuration parameter</secondary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ Sets the maximum number of parallel autovacuum workers that
+ can be used for parallel index vacuuming at one time. Is capped by
+ <xref linkend="guc-max-worker-processes"/>. The default is 2.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</sect2>
diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml
index 7c958b06273..c9f9163c551 100644
--- a/doc/src/sgml/maintenance.sgml
+++ b/doc/src/sgml/maintenance.sgml
@@ -926,6 +926,18 @@ HINT: Execute a database-wide VACUUM in that database.
autovacuum workers' activity.
</para>
+ <para>
+ If an autovacuum worker process comes across a table with the enabled
+ <xref linkend="reloption-autovacuum-parallel-workers"/> storage parameter,
+ it will launch parallel workers in order to vacuum indexes of this table
+ in a parallel mode. Parallel workers are taken from the pool of processes
+ established by <xref linkend="guc-max-worker-processes"/>, limited by
+ <xref linkend="guc-max-parallel-workers"/>.
+ The total number of parallel autovacuum workers that can be active at one
+ time is limited by the <xref linkend="guc-autovacuum-max-parallel-workers"/>
+ configuration parameter.
+ </para>
+
<para>
If several large tables all become eligible for vacuuming in a short
amount of time, all autovacuum workers might become occupied with
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 77c5a763d45..3592c9acff9 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -1717,6 +1717,26 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
</listitem>
</varlistentry>
+ <varlistentry id="reloption-autovacuum-parallel-workers" xreflabel="autovacuum_parallel_workers">
+ <term><literal>autovacuum_parallel_workers</literal> (<type>integer</type>)
+ <indexterm>
+ <primary><varname>autovacuum_parallel_workers</varname> storage parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ Sets the maximum number of parallel autovacuum workers that can process
+ indexes of this table.
+ The default value is -1, which means no parallel index vacuuming for
+ this table. If value is 0 then parallel degree will computed based on
+ number of indexes.
+ Note that the computed number of workers may not actually be available at
+ run time. If this occurs, the autovacuum will run with fewer workers
+ than expected.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="reloption-autovacuum-vacuum-threshold" xreflabel="autovacuum_vacuum_threshold">
<term><literal>autovacuum_vacuum_threshold</literal>, <literal>toast.autovacuum_vacuum_threshold</literal> (<type>integer</type>)
<indexterm>
--
2.43.0
From 411d69b72072316f1e499a59034b7eeded92ce7e Mon Sep 17 00:00:00 2001
From: Daniil Davidov <[email protected]>
Date: Sun, 23 Nov 2025 01:08:14 +0700
Subject: [PATCH v20 4/5] Tests for parallel autovacuum
---
src/backend/commands/vacuumparallel.c | 60 +++
src/backend/postmaster/autovacuum.c | 19 +
src/include/postmaster/autovacuum.h | 1 +
src/test/modules/Makefile | 1 +
src/test/modules/meson.build | 1 +
src/test/modules/test_autovacuum/.gitignore | 2 +
src/test/modules/test_autovacuum/Makefile | 28 ++
src/test/modules/test_autovacuum/meson.build | 36 ++
.../modules/test_autovacuum/t/001_basic.pl | 346 ++++++++++++++++++
.../test_autovacuum/test_autovacuum--1.0.sql | 12 +
.../modules/test_autovacuum/test_autovacuum.c | 41 +++
.../test_autovacuum/test_autovacuum.control | 3 +
12 files changed, 550 insertions(+)
create mode 100644 src/test/modules/test_autovacuum/.gitignore
create mode 100644 src/test/modules/test_autovacuum/Makefile
create mode 100644 src/test/modules/test_autovacuum/meson.build
create mode 100644 src/test/modules/test_autovacuum/t/001_basic.pl
create mode 100644 src/test/modules/test_autovacuum/test_autovacuum--1.0.sql
create mode 100644 src/test/modules/test_autovacuum/test_autovacuum.c
create mode 100644 src/test/modules/test_autovacuum/test_autovacuum.control
diff --git a/src/backend/commands/vacuumparallel.c b/src/backend/commands/vacuumparallel.c
index e3561057334..bb4d2ef3bea 100644
--- a/src/backend/commands/vacuumparallel.c
+++ b/src/backend/commands/vacuumparallel.c
@@ -39,6 +39,7 @@
#include "postmaster/autovacuum.h"
#include "storage/bufmgr.h"
#include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
@@ -280,6 +281,7 @@ static void parallel_vacuum_process_one_index(ParallelVacuumState *pvs, Relation
static bool parallel_vacuum_index_is_parallel_safe(Relation indrel, int num_index_scans,
bool vacuum);
static void parallel_vacuum_error_callback(void *arg);
+static void parallel_vacuum_report_cost_based_params(void);
/*
* Try to enter parallel mode and create a parallel context. Then initialize
@@ -887,6 +889,14 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
pvs->pcxt->nworkers_launched, nworkers)));
}
+ /*
+ * To be able to exercise whether all reserved parallel workers are being
+ * released anyway, allow injection points to trigger a failure at this
+ * point.
+ */
+ if (nworkers > 0)
+ INJECTION_POINT("autovacuum-leader-before-indexes-processing", NULL);
+
/* Vacuum the indexes that can be processed by only leader process */
parallel_vacuum_process_unsafe_indexes(pvs);
@@ -896,6 +906,15 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
*/
parallel_vacuum_process_safe_indexes(pvs);
+ /*
+ * To be able to exercise whether leader parallel autovacuum worker can
+ * propagate cost-based params to parallel workers, wait here until
+ * configuration is changed. I.e. tests are expecting, that during index
+ * processing vacuum_delay_point have been called (if config was changed).
+ */
+ if (nworkers > 0)
+ INJECTION_POINT("autovacuum-leader-after-indexes-processing", NULL);
+
/*
* Next, accumulate buffer and WAL usage. (This must wait for the workers
* to finish, or we might get incomplete data.)
@@ -1261,9 +1280,23 @@ parallel_vacuum_main(dsm_segment *seg, shm_toc *toc)
/* Prepare to track buffer usage during parallel execution */
InstrStartParallelQuery();
+ INJECTION_POINT("parallel-worker-before-indexes-processing", NULL);
+
/* Process indexes to perform vacuum/cleanup */
parallel_vacuum_process_safe_indexes(&pvs);
+#ifdef USE_INJECTION_POINTS
+ /*
+ * There is no guarantee that each parallel worker will necessarily
+ * process at least one index. Thus, at this point we cannot be sure that
+ * worker called vacuum_cost_delay. In order to test cost-based parameters
+ * propagation (from leader worker), call vacuum_delay_point here, if
+ * injection point is active.
+ */
+ if (IS_INJECTION_POINT_ATTACHED("parallel-autovacuum-force-delay-point"))
+ parallel_vacuum_report_cost_based_params();
+#endif
+
/* Report buffer/WAL usage during parallel execution */
buffer_usage = shm_toc_lookup(toc, PARALLEL_VACUUM_KEY_BUFFER_USAGE, false);
wal_usage = shm_toc_lookup(toc, PARALLEL_VACUUM_KEY_WAL_USAGE, false);
@@ -1316,3 +1349,30 @@ parallel_vacuum_error_callback(void *arg)
return;
}
}
+
+/*
+ * Log values of the related to cost-based delay parameters. It is used for
+ * testing purpose.
+ */
+static void
+parallel_vacuum_report_cost_based_params(void)
+{
+ StringInfoData buf;
+
+ /* Simulate config reload during normal processing */
+ pg_atomic_add_fetch_u32(VacuumActiveNWorkers, 1);
+ vacuum_delay_point(false);
+ pg_atomic_sub_fetch_u32(VacuumActiveNWorkers, 1);
+
+ initStringInfo(&buf);
+
+ appendStringInfo(&buf, "Vacuum cost-based delay parameters of parallel worker:\n");
+ appendStringInfo(&buf,"vacuum_cost_limit = %d\n",vacuum_cost_limit);
+ appendStringInfo(&buf, "vacuum_cost_delay = %g\n", vacuum_cost_delay);
+ appendStringInfo(&buf, "vacuum_cost_page_miss = %d\n", VacuumCostPageMiss);
+ appendStringInfo(&buf, "vacuum_cost_page_dirty = %d\n", VacuumCostPageDirty);
+ appendStringInfo(&buf, "vacuum_cost_page_hit = %d\n", VacuumCostPageHit);
+
+ ereport(LOG, errmsg("%s", buf.data));
+ pfree(buf.data);
+}
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 3ee858c5fbd..e6d60434bc5 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -801,6 +801,8 @@ ProcessAutoVacLauncherInterrupts(void)
/* rebuild the list in case the naptime changed */
rebuild_database_list(InvalidOid);
+
+ INJECTION_POINT("autovacuum-launcher-after-reload-config", NULL);
}
/* Process barrier events */
@@ -3467,6 +3469,23 @@ AutoVacuumReleaseAllParallelWorkers(void)
Assert(av_nworkers_reserved == 0);
}
+/*
+ * Get number of free autovacuum parallel workers.
+ *
+ * For testing purpose only!
+ */
+uint32
+AutoVacuumGetFreeParallelWorkers(void)
+{
+ uint32 nfree_workers;
+
+ LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
+ nfree_workers = AutoVacuumShmem->av_freeParallelWorkers;
+ LWLockRelease(AutovacuumLock);
+
+ return nfree_workers;
+}
+
/*
* autovac_init
* This is called at postmaster initialization.
diff --git a/src/include/postmaster/autovacuum.h b/src/include/postmaster/autovacuum.h
index f3783afb51b..52be260e15f 100644
--- a/src/include/postmaster/autovacuum.h
+++ b/src/include/postmaster/autovacuum.h
@@ -66,6 +66,7 @@ extern bool AutoVacuumRequestWork(AutoVacuumWorkItemType type,
extern void AutoVacuumReserveParallelWorkers(int *nworkers);
extern void AutoVacuumReleaseParallelWorkers(int nworkers);
extern void AutoVacuumReleaseAllParallelWorkers(void);
+extern uint32 AutoVacuumGetFreeParallelWorkers(void);
/* shared memory stuff */
extern Size AutoVacuumShmemSize(void);
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 4c6d56d97d8..bfe365fa575 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -16,6 +16,7 @@ SUBDIRS = \
plsample \
spgist_name_ops \
test_aio \
+ test_autovacuum \
test_binaryheap \
test_bitmapset \
test_bloomfilter \
diff --git a/src/test/modules/meson.build b/src/test/modules/meson.build
index 1b31c5b98d6..01a3e3ec044 100644
--- a/src/test/modules/meson.build
+++ b/src/test/modules/meson.build
@@ -16,6 +16,7 @@ subdir('plsample')
subdir('spgist_name_ops')
subdir('ssl_passphrase_callback')
subdir('test_aio')
+subdir('test_autovacuum')
subdir('test_binaryheap')
subdir('test_bitmapset')
subdir('test_bloomfilter')
diff --git a/src/test/modules/test_autovacuum/.gitignore b/src/test/modules/test_autovacuum/.gitignore
new file mode 100644
index 00000000000..716e17f5a2a
--- /dev/null
+++ b/src/test/modules/test_autovacuum/.gitignore
@@ -0,0 +1,2 @@
+# Generated subdirectories
+/tmp_check/
diff --git a/src/test/modules/test_autovacuum/Makefile b/src/test/modules/test_autovacuum/Makefile
new file mode 100644
index 00000000000..32254c53a5d
--- /dev/null
+++ b/src/test/modules/test_autovacuum/Makefile
@@ -0,0 +1,28 @@
+# src/test/modules/test_autovacuum/Makefile
+
+PGFILEDESC = "test_autovacuum - test code for parallel autovacuum"
+
+MODULE_big = test_autovacuum
+OBJS = \
+ $(WIN32RES) \
+ test_autovacuum.o
+
+EXTENSION = test_autovacuum
+DATA = test_autovacuum--1.0.sql
+
+TAP_TESTS = 1
+
+EXTRA_INSTALL = src/test/modules/injection_points
+
+export enable_injection_points
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_autovacuum
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_autovacuum/meson.build b/src/test/modules/test_autovacuum/meson.build
new file mode 100644
index 00000000000..3441e5e49cf
--- /dev/null
+++ b/src/test/modules/test_autovacuum/meson.build
@@ -0,0 +1,36 @@
+# Copyright (c) 2024-2025, PostgreSQL Global Development Group
+
+test_autovacuum_sources = files(
+ 'test_autovacuum.c',
+)
+
+if host_system == 'windows'
+ test_autovacuum_sources += rc_lib_gen.process(win32ver_rc, extra_args: [
+ '--NAME', 'test_autovacuum',
+ '--FILEDESC', 'test_autovacuum - test code for parallel autovacuum',])
+endif
+
+test_autovacuum = shared_module('test_autovacuum',
+ test_autovacuum_sources,
+ kwargs: pg_test_mod_args,
+)
+test_install_libs += test_autovacuum
+
+test_install_data += files(
+ 'test_autovacuum.control',
+ 'test_autovacuum--1.0.sql',
+)
+
+tests += {
+ 'name': 'test_autovacuum',
+ 'sd': meson.current_source_dir(),
+ 'bd': meson.current_build_dir(),
+ 'tap': {
+ 'env': {
+ 'enable_injection_points': get_option('injection_points') ? 'yes' : 'no',
+ },
+ 'tests': [
+ 't/001_basic.pl',
+ ],
+ },
+}
diff --git a/src/test/modules/test_autovacuum/t/001_basic.pl b/src/test/modules/test_autovacuum/t/001_basic.pl
new file mode 100644
index 00000000000..065a58ef2e6
--- /dev/null
+++ b/src/test/modules/test_autovacuum/t/001_basic.pl
@@ -0,0 +1,346 @@
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+if ($ENV{enable_injection_points} ne 'yes')
+{
+ plan skip_all => 'Injection points not supported by this build';
+}
+
+# Before each test we should disable autovacuum for 'test_autovac' table and
+# generate some dead tuples in it.
+
+sub prepare_for_next_test
+{
+ my ($node, $test_number) = @_;
+
+ $node->safe_psql('postgres', qq{
+ ALTER TABLE test_autovac SET (autovacuum_enabled = false);
+ });
+
+ $node->safe_psql('postgres', qq{
+ UPDATE test_autovac SET col_1 = $test_number;
+ ANALYZE test_autovac;
+ });
+}
+
+sub wait_for_av_log
+{
+ my ($node, $expected_log) = @_;
+
+ $node->wait_for_log($expected_log);
+ truncate $node->logfile, 0 or die "truncate failed: $!";
+}
+
+my $psql_out;
+
+my $node = PostgreSQL::Test::Cluster->new('node1');
+$node->init;
+
+# Configure postgres, so it can launch parallel autovacuum workers, log all
+# information we are interested in and autovacuum works frequently
+$node->append_conf('postgresql.conf', qq{
+ max_worker_processes = 20
+ max_parallel_workers = 20
+ max_parallel_maintenance_workers = 20
+ autovacuum_max_parallel_workers = 20
+ log_min_messages = debug2
+ log_autovacuum_min_duration = 0
+ autovacuum_naptime = '1s'
+ min_parallel_index_scan_size = 0
+ shared_preload_libraries=test_autovacuum
+});
+$node->start;
+
+# Check if the extension injection_points is available, as it may be
+# possible that this script is run with installcheck, where the module
+# would not be installed by default.
+if (!$node->check_extension('injection_points'))
+{
+ plan skip_all => 'Extension injection_points not installed';
+}
+
+# Create all functions needed for testing
+$node->safe_psql('postgres', qq{
+ CREATE EXTENSION test_autovacuum;
+ CREATE EXTENSION injection_points;
+});
+
+my $indexes_num = 4;
+my $initial_rows_num = 10_000;
+my $autovacuum_parallel_workers = 2;
+
+# Create table with specified number of b-tree indexes on it
+$node->safe_psql('postgres', qq{
+ CREATE TABLE test_autovac (
+ id SERIAL PRIMARY KEY,
+ col_1 INTEGER, col_2 INTEGER, col_3 INTEGER, col_4 INTEGER
+ ) WITH (autovacuum_parallel_workers = $autovacuum_parallel_workers);
+
+ DO \$\$
+ DECLARE
+ i INTEGER;
+ BEGIN
+ FOR i IN 1..$indexes_num LOOP
+ EXECUTE format('CREATE INDEX idx_col_\%s ON test_autovac (col_\%s);', i, i);
+ END LOOP;
+ END \$\$;
+});
+
+# Insert specified tuples num into the table
+$node->safe_psql('postgres', qq{
+ DO \$\$
+ DECLARE
+ i INTEGER;
+ BEGIN
+ FOR i IN 1..$initial_rows_num LOOP
+ INSERT INTO test_autovac VALUES (i, i + 1, i + 2, i + 3);
+ END LOOP;
+ END \$\$;
+});
+
+# Test 1 :
+# Our table has enough indexes and appropriate reloptions, so autovacuum must
+# be able to process it in parallel mode. Just check if it can.
+# Also check whether all requested workers:
+# 1) launched
+# 2) correctly released
+
+prepare_for_next_test($node, 1);
+
+$node->safe_psql('postgres', qq{
+ ALTER TABLE test_autovac SET (autovacuum_enabled = true);
+});
+
+# Wait until the parallel autovacuum on table is completed. At the same time,
+# we check that the required number of parallel workers has been started.
+wait_for_av_log($node,
+ qr/parallel index vacuum\/cleanup: 2 workers were planned, / .
+ qr/2 workers were reserved and 2 workers were launched in total/);
+
+$node->psql('postgres',
+ "SELECT get_parallel_autovacuum_free_workers();",
+ stdout => \$psql_out,
+);
+is($psql_out, 20, 'All parallel workers has been released by the leader');
+
+# Test 2:
+# Check whether parallel autovacuum leader can propagate cost-based parameters
+# to parallel workers.
+
+prepare_for_next_test($node, 2);
+
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_attach('autovacuum-leader-before-indexes-processing', 'wait');
+ SELECT injection_points_attach('autovacuum-leader-after-indexes-processing', 'wait');
+ SELECT injection_points_attach('parallel-worker-before-indexes-processing', 'wait');
+ SELECT injection_points_attach('parallel-autovacuum-force-delay-point', 'wait');
+
+ ALTER TABLE test_autovac SET (autovacuum_parallel_workers = 1, autovacuum_enabled = true);
+});
+
+# Wait until parallel autovacuum leader launches parallel worker and falls
+# asleep on the injection point
+$node->wait_for_event(
+ 'autovacuum worker',
+ 'autovacuum-leader-before-indexes-processing'
+);
+
+# Reload config - leader worker must update its own parameters during indexes
+# processing
+$node->safe_psql('postgres', qq{
+ ALTER SYSTEM SET vacuum_cost_limit = 500;
+ ALTER SYSTEM SET vacuum_cost_page_miss = 10;
+ ALTER SYSTEM SET vacuum_cost_page_dirty = 10;
+ ALTER SYSTEM SET vacuum_cost_page_hit = 10;
+ SELECT pg_reload_conf();
+});
+
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_wakeup('autovacuum-leader-before-indexes-processing');
+});
+
+# Wait until leader worker is guaranteed to update parameters and propagate
+# their values to the parallel worker
+$node->wait_for_event(
+ 'autovacuum worker',
+ 'autovacuum-leader-after-indexes-processing'
+);
+
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_wakeup('autovacuum-leader-after-indexes-processing');
+});
+
+# Now wake up the parallel worker and force it to call vacuum_delay_point
+$node->wait_for_event(
+ 'parallel worker',
+ 'parallel-worker-before-indexes-processing'
+);
+
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_wakeup('parallel-worker-before-indexes-processing');
+});
+
+# Check whether worker successfully updated all parameters
+wait_for_av_log($node,
+ qr/Vacuum cost-based delay parameters of parallel worker:\n/ .
+ qr/\tvacuum_cost_limit = 500\n/ .
+ qr/\tvacuum_cost_delay = 2\n/ .
+ qr/\tvacuum_cost_page_miss = 10\n/ .
+ qr/\tvacuum_cost_page_dirty = 10\n/ .
+ qr/\tvacuum_cost_page_hit = 10\n/);
+
+# Cleanup
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_detach('autovacuum-leader-before-indexes-processing');
+ SELECT injection_points_detach('autovacuum-leader-after-indexes-processing');
+ SELECT injection_points_detach('parallel-worker-before-indexes-processing');
+ SELECT injection_points_detach('parallel-autovacuum-force-delay-point');
+
+ ALTER TABLE test_autovac SET (autovacuum_parallel_workers = $autovacuum_parallel_workers);
+});
+
+# Test 3:
+# Test adjustment of free parallel workers number when changing
+# autovacuum_max_parallel_workers parameter
+
+prepare_for_next_test($node, 4);
+
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_attach('autovacuum-leader-before-indexes-processing', 'wait');
+ SELECT injection_points_attach('autovacuum-launcher-after-reload-config', 'wait');
+ ALTER TABLE test_autovac SET (autovacuum_enabled = true);
+});
+
+$node->wait_for_event(
+ 'autovacuum worker',
+ 'autovacuum-leader-before-indexes-processing'
+);
+
+$node->safe_psql('postgres', qq{
+ ALTER SYSTEM SET autovacuum_max_parallel_workers = 1;
+ SELECT pg_reload_conf();
+});
+
+$node->wait_for_event(
+ 'autovacuum launcher',
+ 'autovacuum-launcher-after-reload-config'
+);
+
+# Since 2 parallel workers already launched and will be released in the future,
+# we are expecting that :
+# 1) number of free workers will be '0' after config reload
+# 2) number of free workers will be '1' after releasing workers
+
+# Check statement (1)
+$node->psql('postgres',
+ "SELECT get_parallel_autovacuum_free_workers();",
+ stdout => \$psql_out,
+);
+is($psql_out, 0,
+ 'Number of free parallel workers is consistent');
+
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_wakeup('autovacuum-launcher-after-reload-config');
+ SELECT injection_points_wakeup('autovacuum-leader-before-indexes-processing');
+});
+
+# Wait until the end of parallel processing
+wait_for_av_log($node,
+ qr/parallel index vacuum\/cleanup: 2 workers were planned, / .
+ qr/2 workers were reserved and 2 workers were launched in total/);
+
+# Check statement (2)
+$node->psql('postgres',
+ "SELECT get_parallel_autovacuum_free_workers();",
+ stdout => \$psql_out,
+);
+is($psql_out, 1,
+ 'Number of free parallel workers is consistent');
+
+# Cleanup
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_detach('autovacuum-leader-before-indexes-processing');
+ SELECT injection_points_detach('autovacuum-launcher-after-reload-config');
+ ALTER SYSTEM SET autovacuum_max_parallel_workers = 10;
+ SELECT pg_reload_conf();
+});
+
+# Test 4:
+# We want parallel autovacuum workers to be released even if leader gets an
+# error. At first, simulate situation, when leader exites due to an ERROR.
+
+prepare_for_next_test($node, 4);
+
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_attach('autovacuum-leader-before-indexes-processing', 'error');
+ ALTER TABLE test_autovac SET (autovacuum_enabled = true);
+});
+
+wait_for_av_log($node,
+ qr/error triggered for injection point / .
+ qr/autovacuum-leader-before-indexes-processing/);
+
+$node->psql('postgres',
+ "SELECT get_parallel_autovacuum_free_workers();",
+ stdout => \$psql_out,
+);
+is($psql_out, 10,
+ 'All parallel workers has been released by the leader after ERROR');
+
+# Cleanup
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_detach('autovacuum-leader-before-indexes-processing');
+});
+
+# Test 5:
+# Same as above test, but simulate situation, when leader exites due to FATAL.
+
+prepare_for_next_test($node, 5);
+
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_attach('autovacuum-leader-before-indexes-processing', 'wait');
+ ALTER TABLE test_autovac SET (autovacuum_enabled = true);
+});
+
+$node->wait_for_event(
+ 'autovacuum worker',
+ 'autovacuum-leader-before-indexes-processing'
+);
+
+my $av_pid = $node->safe_psql('postgres', qq{
+ SELECT pid FROM pg_stat_activity
+ WHERE backend_type = 'autovacuum worker'
+ AND wait_event = 'autovacuum-leader-before-indexes-processing'
+ LIMIT 1;
+});
+
+# Create role with pg_signal_autovacuum_worker for terminating autovacuum worker.
+$node->safe_psql('postgres', qq{
+ CREATE ROLE regress_worker_role;
+ GRANT pg_signal_autovacuum_worker TO regress_worker_role;
+ SET ROLE regress_worker_role;
+});
+
+$node->safe_psql('postgres', qq{
+ SELECT pg_terminate_backend('$av_pid');
+});
+
+wait_for_av_log($node,
+ qr/terminating autovacuum process due to administrator command/);
+
+$node->psql('postgres',
+ "SELECT get_parallel_autovacuum_free_workers();",
+ stdout => \$psql_out,
+);
+is($psql_out, 10,
+ 'All parallel workers has been released by the leader after FATAL');
+
+# Cleanup
+$node->safe_psql('postgres', qq{
+ SELECT injection_points_detach('autovacuum-leader-before-indexes-processing');
+});
+
+$node->stop;
+done_testing();
diff --git a/src/test/modules/test_autovacuum/test_autovacuum--1.0.sql b/src/test/modules/test_autovacuum/test_autovacuum--1.0.sql
new file mode 100644
index 00000000000..e5646e0def5
--- /dev/null
+++ b/src/test/modules/test_autovacuum/test_autovacuum--1.0.sql
@@ -0,0 +1,12 @@
+/* src/test/modules/test_autovacuum/test_autovacuum--1.0.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_autovacuum" to load this file. \quit
+
+/*
+ * Functions for expecting shared autovacuum state
+ */
+
+CREATE FUNCTION get_parallel_autovacuum_free_workers()
+RETURNS INTEGER STRICT
+AS 'MODULE_PATHNAME' LANGUAGE C;
diff --git a/src/test/modules/test_autovacuum/test_autovacuum.c b/src/test/modules/test_autovacuum/test_autovacuum.c
new file mode 100644
index 00000000000..959629c7685
--- /dev/null
+++ b/src/test/modules/test_autovacuum/test_autovacuum.c
@@ -0,0 +1,41 @@
+/*-------------------------------------------------------------------------
+ *
+ * test_autovacuum.c
+ * Helpers to write tests for parallel autovacuum
+ *
+ * Copyright (c) 2020-2025, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/test/modules/test_autovacuum/test_autovacuum.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "commands/vacuum.h"
+#include "fmgr.h"
+#include "miscadmin.h"
+#include "postmaster/autovacuum.h"
+#include "storage/shmem.h"
+#include "storage/ipc.h"
+#include "storage/lwlock.h"
+#include "utils/builtins.h"
+#include "utils/injection_point.h"
+
+PG_MODULE_MAGIC;
+
+PG_FUNCTION_INFO_V1(get_parallel_autovacuum_free_workers);
+Datum
+get_parallel_autovacuum_free_workers(PG_FUNCTION_ARGS)
+{
+ uint32 nfree_workers;
+
+#ifndef USE_INJECTION_POINTS
+ ereport(ERROR, errmsg("injection points not supported"));
+#endif
+
+ nfree_workers = AutoVacuumGetFreeParallelWorkers();
+
+ PG_RETURN_UINT32(nfree_workers);
+}
diff --git a/src/test/modules/test_autovacuum/test_autovacuum.control b/src/test/modules/test_autovacuum/test_autovacuum.control
new file mode 100644
index 00000000000..1b7fad258f0
--- /dev/null
+++ b/src/test/modules/test_autovacuum/test_autovacuum.control
@@ -0,0 +1,3 @@
+comment = 'Test code for parallel autovacuum'
+default_version = '1.0'
+module_pathname = '$libdir/test_autovacuum'
--
2.43.0
From bbb5df9645dde72fcbb45f7aef141008e03226fa Mon Sep 17 00:00:00 2001
From: Daniil Davidov <[email protected]>
Date: Sun, 23 Nov 2025 01:03:24 +0700
Subject: [PATCH v20 1/5] Parallel autovacuum
---
src/backend/access/common/reloptions.c | 11 ++
src/backend/commands/vacuumparallel.c | 39 +++-
src/backend/postmaster/autovacuum.c | 172 +++++++++++++++++-
src/backend/utils/init/globals.c | 1 +
src/backend/utils/misc/guc.c | 8 +-
src/backend/utils/misc/guc_parameters.dat | 8 +
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/bin/psql/tab-complete.in.c | 1 +
src/include/miscadmin.h | 1 +
src/include/postmaster/autovacuum.h | 5 +
src/include/utils/rel.h | 7 +
11 files changed, 244 insertions(+), 10 deletions(-)
diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index 0b83f98ed5f..692ac46733e 100644
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -222,6 +222,15 @@ static relopt_int intRelOpts[] =
},
SPGIST_DEFAULT_FILLFACTOR, SPGIST_MIN_FILLFACTOR, 100
},
+ {
+ {
+ "autovacuum_parallel_workers",
+ "Maximum number of parallel autovacuum workers that can be used for processing this table.",
+ RELOPT_KIND_HEAP,
+ ShareUpdateExclusiveLock
+ },
+ -1, -1, 1024
+ },
{
{
"autovacuum_vacuum_threshold",
@@ -1881,6 +1890,8 @@ default_reloptions(Datum reloptions, bool validate, relopt_kind kind)
{"fillfactor", RELOPT_TYPE_INT, offsetof(StdRdOptions, fillfactor)},
{"autovacuum_enabled", RELOPT_TYPE_BOOL,
offsetof(StdRdOptions, autovacuum) + offsetof(AutoVacOpts, enabled)},
+ {"autovacuum_parallel_workers", RELOPT_TYPE_INT,
+ offsetof(StdRdOptions, autovacuum) + offsetof(AutoVacOpts, autovacuum_parallel_workers)},
{"autovacuum_vacuum_threshold", RELOPT_TYPE_INT,
offsetof(StdRdOptions, autovacuum) + offsetof(AutoVacOpts, vacuum_threshold)},
{"autovacuum_vacuum_max_threshold", RELOPT_TYPE_INT,
diff --git a/src/backend/commands/vacuumparallel.c b/src/backend/commands/vacuumparallel.c
index c3b3c9ea21a..1e35b82aeaf 100644
--- a/src/backend/commands/vacuumparallel.c
+++ b/src/backend/commands/vacuumparallel.c
@@ -1,7 +1,9 @@
/*-------------------------------------------------------------------------
*
* vacuumparallel.c
- * Support routines for parallel vacuum execution.
+ * Support routines for parallel vacuum and autovacuum execution. In the
+ * comments below, the word "vacuum" will refer to both vacuum and
+ * autovacuum.
*
* This file contains routines that are intended to support setting up, using,
* and tearing down a ParallelVacuumState.
@@ -34,6 +36,7 @@
#include "executor/instrument.h"
#include "optimizer/paths.h"
#include "pgstat.h"
+#include "postmaster/autovacuum.h"
#include "storage/bufmgr.h"
#include "tcop/tcopprot.h"
#include "utils/lsyscache.h"
@@ -373,8 +376,9 @@ parallel_vacuum_init(Relation rel, Relation *indrels, int nindexes,
shared->queryid = pgstat_get_my_query_id();
shared->maintenance_work_mem_worker =
(nindexes_mwm > 0) ?
- maintenance_work_mem / Min(parallel_workers, nindexes_mwm) :
- maintenance_work_mem;
+ vac_work_mem / Min(parallel_workers, nindexes_mwm) :
+ vac_work_mem;
+
shared->dead_items_info.max_bytes = vac_work_mem * (size_t) 1024;
/* Prepare DSA space for dead items */
@@ -553,12 +557,17 @@ parallel_vacuum_compute_workers(Relation *indrels, int nindexes, int nrequested,
int nindexes_parallel_bulkdel = 0;
int nindexes_parallel_cleanup = 0;
int parallel_workers;
+ int max_workers;
+
+ max_workers = AmAutoVacuumWorkerProcess() ?
+ autovacuum_max_parallel_workers :
+ max_parallel_maintenance_workers;
/*
* We don't allow performing parallel operation in standalone backend or
* when parallelism is disabled.
*/
- if (!IsUnderPostmaster || max_parallel_maintenance_workers == 0)
+ if (!IsUnderPostmaster || max_workers == 0)
return 0;
/*
@@ -597,8 +606,8 @@ parallel_vacuum_compute_workers(Relation *indrels, int nindexes, int nrequested,
parallel_workers = (nrequested > 0) ?
Min(nrequested, nindexes_parallel) : nindexes_parallel;
- /* Cap by max_parallel_maintenance_workers */
- parallel_workers = Min(parallel_workers, max_parallel_maintenance_workers);
+ /* Cap by GUC variable */
+ parallel_workers = Min(parallel_workers, max_workers);
return parallel_workers;
}
@@ -646,6 +655,13 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
*/
nworkers = Min(nworkers, pvs->pcxt->nworkers);
+ /*
+ * Reserve workers in autovacuum global state. Note that we may be given
+ * fewer workers than we requested.
+ */
+ if (AmAutoVacuumWorkerProcess() && nworkers > 0)
+ AutoVacuumReserveParallelWorkers(&nworkers);
+
/*
* Set index vacuum status and mark whether parallel vacuum worker can
* process it.
@@ -690,6 +706,13 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
LaunchParallelWorkers(pvs->pcxt);
+ /*
+ * Tell autovacuum that we could not launch all the previously
+ * reserved workers.
+ */
+ if (AmAutoVacuumWorkerProcess() && pvs->pcxt->nworkers_launched < nworkers)
+ AutoVacuumReleaseParallelWorkers(nworkers - pvs->pcxt->nworkers_launched);
+
if (pvs->pcxt->nworkers_launched > 0)
{
/*
@@ -738,6 +761,10 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
for (int i = 0; i < pvs->pcxt->nworkers_launched; i++)
InstrAccumParallelQuery(&pvs->buffer_usage[i], &pvs->wal_usage[i]);
+
+ /* Release all the reserved parallel workers for autovacuum */
+ if (AmAutoVacuumWorkerProcess() && pvs->pcxt->nworkers_launched > 0)
+ AutoVacuumReleaseAllParallelWorkers();
}
/*
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 22379de1e31..ddd7bbdf520 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -151,6 +151,13 @@ int Log_autoanalyze_min_duration = 600000;
static double av_storage_param_cost_delay = -1;
static int av_storage_param_cost_limit = -1;
+/*
+ * Tracks the number of parallel workers currently reserved by the
+ * autovacuum worker. This is non-zero only for the parallel autovacuum
+ * leader process.
+ */
+static int av_nworkers_reserved = 0;
+
/* Flags set by signal handlers */
static volatile sig_atomic_t got_SIGUSR2 = false;
@@ -285,6 +292,8 @@ typedef struct AutoVacuumWorkItem
* av_workItems work item array
* av_nworkersForBalance the number of autovacuum workers to use when
* calculating the per worker cost limit
+ * av_freeParallelWorkers the number of free parallel autovacuum workers
+ * av_maxParallelWorkers the maximum number of parallel autovacuum workers
*
* This struct is protected by AutovacuumLock, except for av_signal and parts
* of the worker list (see above).
@@ -299,6 +308,8 @@ typedef struct
WorkerInfo av_startingWorker;
AutoVacuumWorkItem av_workItems[NUM_WORKITEMS];
pg_atomic_uint32 av_nworkersForBalance;
+ uint32 av_freeParallelWorkers;
+ uint32 av_maxParallelWorkers;
} AutoVacuumShmemStruct;
static AutoVacuumShmemStruct *AutoVacuumShmem;
@@ -361,6 +372,7 @@ static void autovac_report_workitem(AutoVacuumWorkItem *workitem,
static void avl_sigusr2_handler(SIGNAL_ARGS);
static bool av_worker_available(void);
static void check_av_worker_gucs(void);
+static void adjust_free_parallel_workers(int prev_max_parallel_workers);
@@ -760,6 +772,8 @@ ProcessAutoVacLauncherInterrupts(void)
if (ConfigReloadPending)
{
int autovacuum_max_workers_prev = autovacuum_max_workers;
+ int autovacuum_max_parallel_workers_prev =
+ autovacuum_max_parallel_workers;
ConfigReloadPending = false;
ProcessConfigFile(PGC_SIGHUP);
@@ -776,6 +790,15 @@ ProcessAutoVacLauncherInterrupts(void)
if (autovacuum_max_workers_prev != autovacuum_max_workers)
check_av_worker_gucs();
+ /*
+ * If autovacuum_max_parallel_workers changed, we must take care of
+ * the correct value of available parallel autovacuum workers in
+ * shmem.
+ */
+ if (autovacuum_max_parallel_workers_prev !=
+ autovacuum_max_parallel_workers)
+ adjust_free_parallel_workers(autovacuum_max_parallel_workers_prev);
+
/* rebuild the list in case the naptime changed */
rebuild_database_list(InvalidOid);
}
@@ -1380,6 +1403,16 @@ avl_sigusr2_handler(SIGNAL_ARGS)
* AUTOVACUUM WORKER CODE
********************************************************************/
+/*
+ * Make sure that all reserved workers are released, even if parallel
+ * autovacuum leader is finishing due to FATAL error.
+ */
+static void
+autovacuum_worker_before_shmem_exit(int code, Datum arg)
+{
+ AutoVacuumReleaseAllParallelWorkers();
+}
+
/*
* Main entry point for autovacuum worker processes.
*/
@@ -2277,6 +2310,12 @@ do_autovacuum(void)
"Autovacuum Portal",
ALLOCSET_DEFAULT_SIZES);
+ /*
+ * Parallel autovacuum can reserve parallel workers. Make sure that all
+ * reserved workers are released even after FATAL error.
+ */
+ before_shmem_exit(autovacuum_worker_before_shmem_exit, 0);
+
/*
* Perform operations on collected tables.
*/
@@ -2458,6 +2497,12 @@ do_autovacuum(void)
}
PG_CATCH();
{
+ /*
+ * Parallel autovacuum can reserve parallel workers. Make sure
+ * that all reserved workers are released.
+ */
+ AutoVacuumReleaseAllParallelWorkers();
+
/*
* Abort the transaction, start a new one, and proceed with the
* next table in our list.
@@ -2858,8 +2903,12 @@ table_recheck_autovac(Oid relid, HTAB *table_toast_map,
*/
tab->at_params.index_cleanup = VACOPTVALUE_UNSPECIFIED;
tab->at_params.truncate = VACOPTVALUE_UNSPECIFIED;
- /* As of now, we don't support parallel vacuum for autovacuum */
- tab->at_params.nworkers = -1;
+
+ /* Decide whether we need to process indexes of table in parallel. */
+ tab->at_params.nworkers = avopts
+ ? avopts->autovacuum_parallel_workers
+ : -1;
+
tab->at_params.freeze_min_age = freeze_min_age;
tab->at_params.freeze_table_age = freeze_table_age;
tab->at_params.multixact_freeze_min_age = multixact_freeze_min_age;
@@ -3336,6 +3385,88 @@ AutoVacuumRequestWork(AutoVacuumWorkItemType type, Oid relationId,
return result;
}
+/*
+ * Reserves parallel workers for autovacuum.
+ *
+ * nworkers is an in/out parameter; the requested number of parallel workers
+ * to reserve by the caller, and set to the actual number of reserved workers.
+ *
+ * The caller must call AutoVacuumRelease[All]ParallelWorkers() to release the
+ * reserved workers.
+ *
+ * NOTE: We will try to provide as many workers as requested, even if caller
+ * will occupy all available workers.
+ */
+void
+AutoVacuumReserveParallelWorkers(int *nworkers)
+{
+ /* Only leader autovacuum worker can call this function. */
+ Assert(AmAutoVacuumWorkerProcess());
+
+ /* The worker must not have any reserved workers yet */
+ Assert(av_nworkers_reserved == 0);
+
+ LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
+
+ /* Provide as many workers as we can. */
+ *nworkers = Min(AutoVacuumShmem->av_freeParallelWorkers, *nworkers);
+ AutoVacuumShmem->av_freeParallelWorkers -= *nworkers;
+
+ LWLockRelease(AutovacuumLock);
+
+ /* Remember how many workers we have reserved. */
+ av_nworkers_reserved = *nworkers;
+}
+
+/*
+ * Releases the reserved parallel workers for autovacuum.
+ *
+ * This function should be used to release the parallel workers that an
+ * autovacuum worker reserved by AutoVacuumReserveParallelWorkers(). nworkers
+ * is the number of workers to release, which must not be greater than the
+ * number of workers currently reserved, av_nworkers_reserved.
+ */
+void
+AutoVacuumReleaseParallelWorkers(int nworkers)
+{
+ /* Only leader worker can call this function. */
+ Assert(AmAutoVacuumWorkerProcess());
+
+ /* Cannot release more workers than reserved */
+ Assert(nworkers <= av_nworkers_reserved);
+
+ LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
+
+ /*
+ * If the maximum number of parallel workers was reduced during execution,
+ * we must cap available workers number by its new value.
+ */
+ AutoVacuumShmem->av_freeParallelWorkers =
+ Min(AutoVacuumShmem->av_freeParallelWorkers + nworkers,
+ AutoVacuumShmem->av_maxParallelWorkers);
+
+ LWLockRelease(AutovacuumLock);
+
+ /* Don't have to remember these workers anymore. */
+ av_nworkers_reserved -= nworkers;
+}
+
+/*
+ * Same as above, but this function releases all the parallel workers that
+ * this autovacuum worker reserved.
+ */
+void
+AutoVacuumReleaseAllParallelWorkers(void)
+{
+ /* Only leader worker can call this function. */
+ Assert(AmAutoVacuumWorkerProcess());
+
+ if (av_nworkers_reserved > 0)
+ AutoVacuumReleaseParallelWorkers(av_nworkers_reserved);
+
+ Assert(av_nworkers_reserved == 0);
+}
+
/*
* autovac_init
* This is called at postmaster initialization.
@@ -3396,6 +3527,10 @@ AutoVacuumShmemInit(void)
Assert(!found);
AutoVacuumShmem->av_launcherpid = 0;
+ AutoVacuumShmem->av_maxParallelWorkers =
+ Min(autovacuum_max_parallel_workers, max_worker_processes);
+ AutoVacuumShmem->av_freeParallelWorkers =
+ AutoVacuumShmem->av_maxParallelWorkers;
dclist_init(&AutoVacuumShmem->av_freeWorkers);
dlist_init(&AutoVacuumShmem->av_runningWorkers);
AutoVacuumShmem->av_startingWorker = NULL;
@@ -3477,3 +3612,36 @@ check_av_worker_gucs(void)
errdetail("The server will only start up to \"autovacuum_worker_slots\" (%d) autovacuum workers at a given time.",
autovacuum_worker_slots)));
}
+
+/*
+ * Adjusts the number of free parallel workers corresponds to the new
+ * autovacuum_max_parallel_workers value.
+ */
+static void
+adjust_free_parallel_workers(int prev_max_parallel_workers)
+{
+ int nfree_workers;
+
+ LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
+
+ nfree_workers =
+ autovacuum_max_parallel_workers - prev_max_parallel_workers +
+ AutoVacuumShmem->av_freeParallelWorkers;
+
+ /*
+ * Cap or increase number of free parallel workers according to the
+ * parameter change.
+ */
+ AutoVacuumShmem->av_freeParallelWorkers = Max(nfree_workers, 0);
+
+ /*
+ * Don't allow number of free workers to become less than zero if the
+ * patameter was decreased.
+ */
+ AutoVacuumShmem->av_freeParallelWorkers =
+ Max(AutoVacuumShmem->av_freeParallelWorkers, 0);
+
+ AutoVacuumShmem->av_maxParallelWorkers = autovacuum_max_parallel_workers;
+
+ LWLockRelease(AutovacuumLock);
+}
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..8265a82b639 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -143,6 +143,7 @@ int NBuffers = 16384;
int MaxConnections = 100;
int max_worker_processes = 8;
int max_parallel_workers = 8;
+int autovacuum_max_parallel_workers = 2;
int MaxBackends = 0;
/* GUC parameters for vacuum */
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index ae9d5f3fb70..c8a99a67767 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -3326,9 +3326,13 @@ set_config_with_handle(const char *name, config_handle *handle,
*
* Also allow normal setting if the GUC is marked GUC_ALLOW_IN_PARALLEL.
*
- * Other changes might need to affect other workers, so forbid them.
+ * Other changes might need to affect other workers, so forbid them. Note,
+ * that parallel autovacuum leader is an exception, because only
+ * cost-based delays need to be affected also to parallel vacuum workers,
+ * and we will handle it elsewhere if appropriate.
*/
- if (IsInParallelMode() && changeVal && action != GUC_ACTION_SAVE &&
+ if (IsInParallelMode() && !AmAutoVacuumWorkerProcess() && changeVal &&
+ action != GUC_ACTION_SAVE &&
(record->flags & GUC_ALLOW_IN_PARALLEL) == 0)
{
ereport(elevel,
diff --git a/src/backend/utils/misc/guc_parameters.dat b/src/backend/utils/misc/guc_parameters.dat
index 7c60b125564..492f66a6872 100644
--- a/src/backend/utils/misc/guc_parameters.dat
+++ b/src/backend/utils/misc/guc_parameters.dat
@@ -154,6 +154,14 @@
max => '2000000000',
},
+{ name => 'autovacuum_max_parallel_workers', type => 'int', context => 'PGC_SIGHUP', group => 'VACUUM_AUTOVACUUM',
+ short_desc => 'Maximum number of parallel autovacuum workers, that can be taken from bgworkers pool.',
+ variable => 'autovacuum_max_parallel_workers',
+ boot_val => '2',
+ min => '0',
+ max => 'MAX_BACKENDS',
+},
+
{ name => 'autovacuum_max_workers', type => 'int', context => 'PGC_SIGHUP', group => 'VACUUM_AUTOVACUUM',
short_desc => 'Sets the maximum number of simultaneously running autovacuum worker processes.',
variable => 'autovacuum_max_workers',
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index dc9e2255f8a..7b536e81791 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -691,6 +691,7 @@
#autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
# (change requires restart)
#autovacuum_max_workers = 3 # max number of autovacuum subprocesses
+#autovacuum_max_parallel_workers = 2 # limited by max_worker_processes
#autovacuum_naptime = 1min # time between autovacuum runs
#autovacuum_vacuum_threshold = 50 # min number of row updates before
# vacuum
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 8b91bc00062..ed59a21289c 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1423,6 +1423,7 @@ static const char *const table_storage_parameters[] = {
"autovacuum_multixact_freeze_max_age",
"autovacuum_multixact_freeze_min_age",
"autovacuum_multixact_freeze_table_age",
+ "autovacuum_parallel_workers",
"autovacuum_vacuum_cost_delay",
"autovacuum_vacuum_cost_limit",
"autovacuum_vacuum_insert_scale_factor",
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index db559b39c4d..ad6e19f426c 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -178,6 +178,7 @@ extern PGDLLIMPORT int MaxBackends;
extern PGDLLIMPORT int MaxConnections;
extern PGDLLIMPORT int max_worker_processes;
extern PGDLLIMPORT int max_parallel_workers;
+extern PGDLLIMPORT int autovacuum_max_parallel_workers;
extern PGDLLIMPORT int commit_timestamp_buffers;
extern PGDLLIMPORT int multixact_member_buffers;
diff --git a/src/include/postmaster/autovacuum.h b/src/include/postmaster/autovacuum.h
index 5aa0f3a8ac1..f3783afb51b 100644
--- a/src/include/postmaster/autovacuum.h
+++ b/src/include/postmaster/autovacuum.h
@@ -62,6 +62,11 @@ pg_noreturn extern void AutoVacWorkerMain(const void *startup_data, size_t start
extern bool AutoVacuumRequestWork(AutoVacuumWorkItemType type,
Oid relationId, BlockNumber blkno);
+/* parallel autovacuum stuff */
+extern void AutoVacuumReserveParallelWorkers(int *nworkers);
+extern void AutoVacuumReleaseParallelWorkers(int nworkers);
+extern void AutoVacuumReleaseAllParallelWorkers(void);
+
/* shared memory stuff */
extern Size AutoVacuumShmemSize(void);
extern void AutoVacuumShmemInit(void);
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index d03ab247788..c1d882659f9 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -311,6 +311,13 @@ typedef struct ForeignKeyCacheInfo
typedef struct AutoVacOpts
{
bool enabled;
+
+ /*
+ * Max number of parallel autovacuum workers. If value is 0 then parallel
+ * degree will computed based on number of indexes.
+ */
+ int autovacuum_parallel_workers;
+
int vacuum_threshold;
int vacuum_max_threshold;
int vacuum_ins_threshold;
--
2.43.0
From aa86e425e5f7a4c8247b8f6d39d852de36e37456 Mon Sep 17 00:00:00 2001
From: Daniil Davidov <[email protected]>
Date: Thu, 15 Jan 2026 23:15:48 +0700
Subject: [PATCH v20 3/5] Cost based parameters propagation for parallel
autovacuum
---
src/backend/commands/vacuum.c | 29 +++++-
src/backend/commands/vacuumparallel.c | 134 ++++++++++++++++++++++++++
src/backend/postmaster/autovacuum.c | 2 +-
src/include/commands/vacuum.h | 2 +
4 files changed, 164 insertions(+), 3 deletions(-)
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index aa4fbec143f..3cc84bedfb7 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -2430,8 +2430,27 @@ vacuum_delay_point(bool is_analyze)
/* Always check for interrupts */
CHECK_FOR_INTERRUPTS();
- if (InterruptPending ||
- (!VacuumCostActive && !ConfigReloadPending))
+ if (InterruptPending)
+ return;
+
+ if (!AmAutoVacuumWorkerProcess() && IsParallelWorker())
+ {
+ /*
+ * If we are parallel *autovacuum* worker, check whether related to
+ * cost-based delay parameters had changed in the leader worker. If
+ * so, corresponding parameters will be updated to the values which
+ * leader worker is operating on.
+ *
+ * Do it before checking VacuumCostActive, because its value might be
+ * changed after leader's parameters consumption.
+ *
+ * Note, that this function has no effect if we are non-autovacuum
+ * parallel worker.
+ */
+ parallel_vacuum_update_shared_delay_params();
+ }
+
+ if (!VacuumCostActive && !ConfigReloadPending)
return;
/*
@@ -2445,6 +2464,12 @@ vacuum_delay_point(bool is_analyze)
ConfigReloadPending = false;
ProcessConfigFile(PGC_SIGHUP);
VacuumUpdateCosts();
+
+ /*
+ * If we are parallel autovacuum leader and some of cost-based
+ * parameters had changed, let other parallel workers know.
+ */
+ parallel_vacuum_propagate_cost_based_params();
}
/*
diff --git a/src/backend/commands/vacuumparallel.c b/src/backend/commands/vacuumparallel.c
index 44c1258b69e..e3561057334 100644
--- a/src/backend/commands/vacuumparallel.c
+++ b/src/backend/commands/vacuumparallel.c
@@ -53,6 +53,39 @@
#define PARALLEL_VACUUM_KEY_WAL_USAGE 4
#define PARALLEL_VACUUM_KEY_INDEX_STATS 5
+/*
+ * Only autovacuum leader can reload config file. We use this structure in
+ * parallel autovacuum for keeping worker's parameters in sync with leader's
+ * parameters.
+ */
+typedef struct PVSharedCostParams
+{
+ /*
+ * Each time leader worker updates its parameters, it must increase
+ * generation. Every parallel worker keeps the generation
+ * (shared_params_local_generation) at which it had last time received
+ * parameters from the leader.
+ *
+ * It is enough for worker to compare it's local_generation with the field
+ * below to determine whether it needs to receive new parameters' values.
+ */
+ pg_atomic_uint32 generation;
+
+ slock_t spinlock; /* protects all fields below */
+
+ /* Copies of corresponding parameters from autovacuum leader process */
+ double cost_delay;
+ int cost_limit;
+ int cost_page_dirty;
+ int cost_page_hit;
+ int cost_page_miss;
+} PVSharedCostParams;
+
+static PVSharedCostParams * pv_shared_cost_params = NULL;
+
+/* See comments for structure above for the explanation. */
+static uint32 shared_params_generation_local = 0;
+
/*
* Shared information among parallel workers. So this is allocated in the DSM
* segment.
@@ -122,6 +155,18 @@ typedef struct PVShared
/* Statistics of shared dead items */
VacDeadItemsInfo dead_items_info;
+
+ /*
+ * If 'true' then we are running parallel autovacuum. Otherwise, we are
+ * running parallel maintenence VACUUM.
+ */
+ bool am_parallel_autovacuum;
+
+ /*
+ * Struct for syncing parameters between supportive parallel autovacuum
+ * workers with leader worker.
+ */
+ PVSharedCostParams cost_params;
} PVShared;
/* Status used during parallel index vacuum or cleanup */
@@ -395,6 +440,20 @@ parallel_vacuum_init(Relation rel, Relation *indrels, int nindexes,
pg_atomic_init_u32(&(shared->active_nworkers), 0);
pg_atomic_init_u32(&(shared->idx), 0);
+ shared->am_parallel_autovacuum = AmAutoVacuumWorkerProcess();
+
+ if (shared->am_parallel_autovacuum)
+ {
+ shared->cost_params.cost_delay = vacuum_cost_delay;
+ shared->cost_params.cost_limit = vacuum_cost_limit;
+ shared->cost_params.cost_page_dirty = VacuumCostPageDirty;
+ shared->cost_params.cost_page_hit = VacuumCostPageHit;
+ shared->cost_params.cost_page_miss = VacuumCostPageMiss;
+ pg_atomic_init_u32(&shared->cost_params.generation, 0);
+ SpinLockInit(&shared->cost_params.spinlock);
+ pv_shared_cost_params = &(shared->cost_params);
+ }
+
shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_SHARED, shared);
pvs->shared = shared;
@@ -537,6 +596,78 @@ parallel_vacuum_cleanup_all_indexes(ParallelVacuumState *pvs, long num_table_tup
parallel_vacuum_process_all_indexes(pvs, num_index_scans, false, wusage);
}
+/*
+ * Function to be called from parallel autovacuum worker in order to sync
+ * some cost-based delay parameter with the leader worker.
+ */
+void
+parallel_vacuum_update_shared_delay_params(void)
+{
+ uint32 params_generation;
+
+ Assert(IsParallelWorker());
+
+ /* Check whether we are running parallel autovacuum */
+ if (pv_shared_cost_params == NULL)
+ return;
+
+ params_generation = pg_atomic_read_u32(&pv_shared_cost_params->generation);
+ Assert(shared_params_generation_local <= params_generation);
+
+ /* Return if parameters had not changed in the leader */
+ if (params_generation == shared_params_generation_local)
+ return;
+
+ SpinLockAcquire(&pv_shared_cost_params->spinlock);
+
+ VacuumCostDelay = pv_shared_cost_params->cost_delay;
+ VacuumCostLimit = pv_shared_cost_params->cost_limit;
+ VacuumCostPageDirty = pv_shared_cost_params->cost_page_dirty;
+ VacuumCostPageHit = pv_shared_cost_params->cost_page_hit;
+ VacuumCostPageMiss = pv_shared_cost_params->cost_page_miss;
+
+ SpinLockRelease(&pv_shared_cost_params->spinlock);
+
+ VacuumUpdateCosts();
+
+ shared_params_generation_local = params_generation;
+}
+
+/*
+ * Function to be called from parallel autovacuum leader in order to propagate
+ * some cost-based parameters to the supportive workers.
+ */
+void
+parallel_vacuum_propagate_cost_based_params(void)
+{
+ uint32 params_generation;
+
+ Assert(AmAutoVacuumWorkerProcess());
+
+ /* Check whether we are running parallel autovacuum */
+ if (pv_shared_cost_params == NULL)
+ return;
+
+ params_generation = pg_atomic_read_u32(&pv_shared_cost_params->generation);
+
+ SpinLockAcquire(&pv_shared_cost_params->spinlock);
+
+ pv_shared_cost_params->cost_delay = vacuum_cost_delay;
+ pv_shared_cost_params->cost_limit = vacuum_cost_limit;
+ pv_shared_cost_params->cost_page_dirty = VacuumCostPageDirty;
+ pv_shared_cost_params->cost_page_hit = VacuumCostPageHit;
+ pv_shared_cost_params->cost_page_miss = VacuumCostPageMiss;
+
+ /*
+ * Increase generation of the parameters, i.e. let parallel workers know
+ * that they should re-read shared cost params.
+ */
+ pg_atomic_write_u32(&pv_shared_cost_params->generation,
+ params_generation + 1);
+
+ SpinLockRelease(&pv_shared_cost_params->spinlock);
+}
+
/*
* Compute the number of parallel worker processes to request. Both index
* vacuum and index cleanup can be executed with parallel workers.
@@ -1100,6 +1231,9 @@ parallel_vacuum_main(dsm_segment *seg, shm_toc *toc)
VacuumSharedCostBalance = &(shared->cost_balance);
VacuumActiveNWorkers = &(shared->active_nworkers);
+ if (shared->am_parallel_autovacuum)
+ pv_shared_cost_params = &(shared->cost_params);
+
/* Set parallel vacuum state */
pvs.indrels = indrels;
pvs.nindexes = nindexes;
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index ddd7bbdf520..3ee858c5fbd 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -1692,7 +1692,7 @@ VacuumUpdateCosts(void)
}
else
{
- /* Must be explicit VACUUM or ANALYZE */
+ /* Must be explicit VACUUM or ANALYZE or parallel autovacuum worker */
vacuum_cost_delay = VacuumCostDelay;
vacuum_cost_limit = VacuumCostLimit;
}
diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h
index 7cbb59d124f..712e1254613 100644
--- a/src/include/commands/vacuum.h
+++ b/src/include/commands/vacuum.h
@@ -414,6 +414,8 @@ extern void parallel_vacuum_cleanup_all_indexes(ParallelVacuumState *pvs,
int num_index_scans,
bool estimated_count,
PVWorkersUsage *wusage);
+extern void parallel_vacuum_update_shared_delay_params(void);
+extern void parallel_vacuum_propagate_cost_based_params(void);
extern void parallel_vacuum_main(dsm_segment *seg, shm_toc *toc);
/* in commands/analyze.c */
--
2.43.0
From 5d3a26a6441f6358505e853d15634e829ac06b05 Mon Sep 17 00:00:00 2001
From: Daniil Davidov <[email protected]>
Date: Sun, 23 Nov 2025 01:07:47 +0700
Subject: [PATCH v20 2/5] Logging for parallel autovacuum
---
src/backend/access/heap/vacuumlazy.c | 33 +++++++++++++++++++++++++--
src/backend/commands/vacuumparallel.c | 27 +++++++++++++++++-----
src/include/commands/vacuum.h | 19 +++++++++++++--
src/tools/pgindent/typedefs.list | 1 +
4 files changed, 70 insertions(+), 10 deletions(-)
diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 1fcb212ab3d..8d6998c6f6f 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -347,6 +347,12 @@ typedef struct LVRelState
int num_index_scans;
int num_dead_items_resets;
Size total_dead_items_bytes;
+
+ /*
+ * Total number of planned and actually launched parallel workers for
+ * index scans.
+ */
+ PVWorkersUsage workers_usage;
/* Counters that follow are only for scanned_pages */
int64 tuples_deleted; /* # deleted from table */
int64 tuples_frozen; /* # newly frozen */
@@ -781,6 +787,9 @@ heap_vacuum_rel(Relation rel, const VacuumParams params,
vacrel->vm_new_visible_frozen_pages = 0;
vacrel->vm_new_frozen_pages = 0;
+ vacrel->workers_usage.nlaunched = 0;
+ vacrel->workers_usage.nplanned = 0;
+
/*
* Get cutoffs that determine which deleted tuples are considered DEAD,
* not just RECENTLY_DEAD, and which XIDs/MXIDs to freeze. Then determine
@@ -1123,6 +1132,24 @@ heap_vacuum_rel(Relation rel, const VacuumParams params,
orig_rel_pages == 0 ? 100.0 :
100.0 * vacrel->lpdead_item_pages / orig_rel_pages,
vacrel->lpdead_items);
+ if (vacrel->workers_usage.nplanned > 0 &&
+ AmAutoVacuumWorkerProcess())
+ {
+ /* Worker usage stats for parallel autovacuum */
+ appendStringInfo(&buf,
+ _("parallel index vacuum/cleanup: %d workers were planned, %d workers were reserved and %d workers were launched in total\n"),
+ vacrel->workers_usage.nplanned,
+ vacrel->workers_usage.nreserved,
+ vacrel->workers_usage.nlaunched);
+ }
+ else if (vacrel->workers_usage.nplanned > 0)
+ {
+ /* Worker usage stats for manual VACUUM (PARALLEL) */
+ appendStringInfo(&buf,
+ _("parallel index vacuum/cleanup: %d workers were planned and %d workers were launched in total\n"),
+ vacrel->workers_usage.nplanned,
+ vacrel->workers_usage.nlaunched);
+ }
for (int i = 0; i < vacrel->nindexes; i++)
{
IndexBulkDeleteResult *istat = vacrel->indstats[i];
@@ -2698,7 +2725,8 @@ lazy_vacuum_all_indexes(LVRelState *vacrel)
{
/* Outsource everything to parallel variant */
parallel_vacuum_bulkdel_all_indexes(vacrel->pvs, old_live_tuples,
- vacrel->num_index_scans);
+ vacrel->num_index_scans,
+ &vacrel->workers_usage);
/*
* Do a postcheck to consider applying wraparound failsafe now. Note
@@ -3131,7 +3159,8 @@ lazy_cleanup_all_indexes(LVRelState *vacrel)
/* Outsource everything to parallel variant */
parallel_vacuum_cleanup_all_indexes(vacrel->pvs, reltuples,
vacrel->num_index_scans,
- estimated_count);
+ estimated_count,
+ &vacrel->workers_usage);
}
/* Reset the progress counters */
diff --git a/src/backend/commands/vacuumparallel.c b/src/backend/commands/vacuumparallel.c
index 1e35b82aeaf..44c1258b69e 100644
--- a/src/backend/commands/vacuumparallel.c
+++ b/src/backend/commands/vacuumparallel.c
@@ -227,7 +227,7 @@ struct ParallelVacuumState
static int parallel_vacuum_compute_workers(Relation *indrels, int nindexes, int nrequested,
bool *will_parallel_vacuum);
static void parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scans,
- bool vacuum);
+ bool vacuum, PVWorkersUsage *wusage);
static void parallel_vacuum_process_safe_indexes(ParallelVacuumState *pvs);
static void parallel_vacuum_process_unsafe_indexes(ParallelVacuumState *pvs);
static void parallel_vacuum_process_one_index(ParallelVacuumState *pvs, Relation indrel,
@@ -502,7 +502,7 @@ parallel_vacuum_reset_dead_items(ParallelVacuumState *pvs)
*/
void
parallel_vacuum_bulkdel_all_indexes(ParallelVacuumState *pvs, long num_table_tuples,
- int num_index_scans)
+ int num_index_scans, PVWorkersUsage *wusage)
{
Assert(!IsParallelWorker());
@@ -513,7 +513,7 @@ parallel_vacuum_bulkdel_all_indexes(ParallelVacuumState *pvs, long num_table_tup
pvs->shared->reltuples = num_table_tuples;
pvs->shared->estimated_count = true;
- parallel_vacuum_process_all_indexes(pvs, num_index_scans, true);
+ parallel_vacuum_process_all_indexes(pvs, num_index_scans, true, wusage);
}
/*
@@ -521,7 +521,8 @@ parallel_vacuum_bulkdel_all_indexes(ParallelVacuumState *pvs, long num_table_tup
*/
void
parallel_vacuum_cleanup_all_indexes(ParallelVacuumState *pvs, long num_table_tuples,
- int num_index_scans, bool estimated_count)
+ int num_index_scans, bool estimated_count,
+ PVWorkersUsage *wusage)
{
Assert(!IsParallelWorker());
@@ -533,7 +534,7 @@ parallel_vacuum_cleanup_all_indexes(ParallelVacuumState *pvs, long num_table_tup
pvs->shared->reltuples = num_table_tuples;
pvs->shared->estimated_count = estimated_count;
- parallel_vacuum_process_all_indexes(pvs, num_index_scans, false);
+ parallel_vacuum_process_all_indexes(pvs, num_index_scans, false, wusage);
}
/*
@@ -618,7 +619,7 @@ parallel_vacuum_compute_workers(Relation *indrels, int nindexes, int nrequested,
*/
static void
parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scans,
- bool vacuum)
+ bool vacuum, PVWorkersUsage *wusage)
{
int nworkers;
PVIndVacStatus new_status;
@@ -655,13 +656,23 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
*/
nworkers = Min(nworkers, pvs->pcxt->nworkers);
+ /* Remember this value, if we asked to */
+ if (wusage != NULL && nworkers > 0)
+ wusage->nplanned += nworkers;
+
/*
* Reserve workers in autovacuum global state. Note that we may be given
* fewer workers than we requested.
*/
if (AmAutoVacuumWorkerProcess() && nworkers > 0)
+ {
AutoVacuumReserveParallelWorkers(&nworkers);
+ /* Remember this value, if we asked to */
+ if (wusage != NULL)
+ wusage->nreserved += nworkers;
+ }
+
/*
* Set index vacuum status and mark whether parallel vacuum worker can
* process it.
@@ -725,6 +736,10 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
/* Enable shared cost balance for leader backend */
VacuumSharedCostBalance = &(pvs->shared->cost_balance);
VacuumActiveNWorkers = &(pvs->shared->active_nworkers);
+
+ /* Remember this value, if we asked to */
+ if (wusage != NULL)
+ wusage->nlaunched += pvs->pcxt->nworkers_launched;
}
if (vacuum)
diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h
index e885a4b9c77..7cbb59d124f 100644
--- a/src/include/commands/vacuum.h
+++ b/src/include/commands/vacuum.h
@@ -300,6 +300,19 @@ typedef struct VacDeadItemsInfo
int64 num_items; /* current # of entries */
} VacDeadItemsInfo;
+/*
+ * PVWorkersUsage stores information about total number of launched, reserved
+ * and planned workers during parallel vacuum.
+ */
+typedef struct PVWorkersUsage
+{
+ int nplanned; /* # of parallel workers we are planned to
+ * launch */
+ int nreserved; /* for autovacuum only - # of parallel workers
+ * we have managed to reserve */
+ int nlaunched; /* # of launched parallel workers */
+} PVWorkersUsage;
+
/* GUC parameters */
extern PGDLLIMPORT int default_statistics_target; /* PGDLLIMPORT for PostGIS */
extern PGDLLIMPORT int vacuum_freeze_min_age;
@@ -394,11 +407,13 @@ extern TidStore *parallel_vacuum_get_dead_items(ParallelVacuumState *pvs,
extern void parallel_vacuum_reset_dead_items(ParallelVacuumState *pvs);
extern void parallel_vacuum_bulkdel_all_indexes(ParallelVacuumState *pvs,
long num_table_tuples,
- int num_index_scans);
+ int num_index_scans,
+ PVWorkersUsage *wusage);
extern void parallel_vacuum_cleanup_all_indexes(ParallelVacuumState *pvs,
long num_table_tuples,
int num_index_scans,
- bool estimated_count);
+ bool estimated_count,
+ PVWorkersUsage *wusage);
extern void parallel_vacuum_main(dsm_segment *seg, shm_toc *toc);
/* in commands/analyze.c */
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 3f3a888fd0e..afebde72235 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2404,6 +2404,7 @@ PullFilterOps
PushFilter
PushFilterOps
PushFunction
+PVWorkersUsage
PyCFunction
PyMethodDef
PyModuleDef
--
2.43.0
