Hi,
On Tue, Jan 6, 2026 at 1:51 AM Masahiko Sawada <[email protected]> wrote:
>
> On Sun, Nov 23, 2025 at 7:02 AM Daniil Davydov <[email protected]> wrote:
> >
> > Hi,
> >
> > On Sun, Nov 23, 2025 at 5:51 AM Sami Imseih <[email protected]> wrote:
> > >
> > > > > nworkers has a double meaning. The return value of
> > > > > AutoVacuumReserveParallelWorkers
> > > > > is nreserved. I think this should be
> > > > >
> > > > > ```
> > > > > nreserved = AutoVacuumReserveParallelWorkers(nworkers);
> > > > > ```
> > > > >
> > > > > and nreserved becomes the authoritative value for the number of
> > > > > parallel
> > > > > workers after that point.
> > >
> > > I could not find this pattern being used in the code base.
> > > I think it will be better and more in-line without what we generally do
> > > and pass-by-reference and update the value inside
> > > AutoVacuumReserveParallelWorkers:
> > >
> > > ```
> > > AutoVacuumReserveParallelWorkers(&nworkers).
> > > ```
> >
> > Maybe I just don't like functions with side effects, but this function will
> > have ones anyway. I'll add logic with passing by reference as you
> > suggested.
> >
> > >
> > > >> ---
> > > >> { 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.',
> > > >> long_desc => 'This parameter is capped by "max_worker_processes"
> > > >> (not by "autovacuum_max_workers"!).',
> > > >> variable => 'autovacuum_max_parallel_workers',
> > > >> boot_val => '0',
> > > >> min => '0',
> > > >> max => 'MAX_BACKENDS',
> > > >> },
> > > >>
> > > >> Parallel vacuum in autovacuum can be used only when users set the
> > > >> autovacuum_parallel_workers storage parameter. How about using the
> > > >> default value 2 for autovacuum_max_parallel_workers GUC parameter?
> > >
> > > > Sounds reasonable, +1 for it.
> > >
> > > v15-0004 has an incorrect default value for
> > > `autovacuum_max_parallel_workers`.
> > > It should now be 2.
> > >
> > > + 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 0,
> > > + which means no parallel index vacuuming.
> >
> > Thanks for noticing it! Fixed.
> >
> > I am sending an updated set of patches.
>
> Thank you for updating the patch! I've reviewed the 0001 patch and
> here are some comments:
Thank you for the review!
>
> ---
> + /* Remember how many workers we have reserved. */
> + av_nworkers_reserved += *nworkers;
>
> I think we can simply assign *nworkers to av_nworkers_reserved instead
> of incrementing it as we're sure that av_nworkers_reserved is 0 at the
> beginning of this function.
Agree, it will be more clear.
>
> ---
> +static void
> +AutoVacuumReleaseAllParallelWorkers(void)
> +{
> + /* Only leader worker can call this function. */
> + Assert(AmAutoVacuumWorkerProcess() && !IsParallelWorker());
> +
> + if (av_nworkers_reserved > 0)
> + AutoVacuumReleaseParallelWorkers(av_nworkers_reserved);
> +}
>
> We can put an assertion at the end of the function to verify that this
> worker doesn't reserve any worker.
It's not a problem to add this assertion, but I have doubts : we have a
function that promises to release a given number of workers, but we are
still checking whether a specified number of workers have been released.
I suggest another place for assertion - see comment below.
>
> ---
> +static void
> +autovacuum_worker_before_shmem_exit(int code, Datum arg)
> +{
> + if (code != 0)
> + AutoVacuumReleaseAllParallelWorkers();
> +}
>
> I think it would be more future-proof if we call
> AutoVacuumReleaseAllParallelWorkers() regardless of the code if there
> is no strong reason why we check the code there.
I think we can leave "code != 0" so as not to confuse the readers, but
add the assertion that at the end of the function all workers have been
released. Thus, we are telling that 1) in normal processing we must not
have reserved workers and 2) even after a FATAL error we are sure
that we don't have reserved workers.
>
> ---
> + before_shmem_exit(autovacuum_worker_before_shmem_exit, 0);
>
> /*
> * Create a per-backend PGPROC struct in shared memory. We must do this
> * before we can use LWLocks or access any shared memory.
> */
> InitProcess();
>
> I think it's better to register the
> autovacuum_worker_before_shmem_exit() after the process
> initialization. The function could use LWLocks to release the reserved
> workers. Given that AutoVacuumReleaseAllParallelWorkers() doesn't try
> to release the reserved worker when av_nworkers_reserved == 0, but it
> would be more future-proof to do that after the basic process
> initialization processes.
My bad, I miss the comment above InitProcess. Agree with you.
Just in case, callback registration will be invoked after BaseInit.
>
> How about renaming autovacuum_worker_before_shmem_exit() to
> autovacuum_worker_onexit()?
We also have "on_shmem_exit" callbacks. Maybe "onexit" naming can confuse
somebody?..
Since the function name does not cross line length boundary anywhere, I suggest
leaving the current naming.
> ---
> IIUC the patch needs to implement some logic to propagate the updates
> of vacuum delay parameters to parallel vacuum workers.
Yep.
> Are you still working on it? Or shall I draft this part on top of the
> 0001 patch?
I thought about some "beautiful" approach, but for now I have
only one idea - force parallel a/v workers to get values for these
parameters from shmem (which obviously can be modified by the
leader a/v process). I'll post this patch in the near future.
Please, see v17 patches (only 0001 has been changed).
--
Best regards,
Daniil Davydov
From 0aafa271ec90dbe494eea79fd484a4856023b3a8 Mon Sep 17 00:00:00 2001
From: Daniil Davidov <[email protected]>
Date: Sun, 23 Nov 2025 01:07:47 +0700
Subject: [PATCH v17 2/4] Logging for parallel autovacuum
---
src/backend/access/heap/vacuumlazy.c | 27 +++++++++++++++++++++++++--
src/backend/commands/vacuumparallel.c | 20 ++++++++++++++------
src/include/commands/vacuum.h | 16 ++++++++++++++--
src/tools/pgindent/typedefs.list | 1 +
4 files changed, 54 insertions(+), 10 deletions(-)
diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 2086a577199..35d2b07aa8a 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -349,6 +349,12 @@ typedef struct LVRelState
int num_index_scans;
int num_dead_items_resets;
Size total_dead_items_bytes;
+
+ /*
+ * Number of planned and actually launched parallel workers for all index
+ * scans, or NULL
+ */
+ PVWorkersUsage *workers_usage;
/* Counters that follow are only for scanned_pages */
int64 tuples_deleted; /* # deleted from table */
int64 tuples_frozen; /* # newly frozen */
@@ -711,6 +717,16 @@ heap_vacuum_rel(Relation rel, const VacuumParams params,
indnames = palloc_array(char *, vacrel->nindexes);
for (int i = 0; i < vacrel->nindexes; i++)
indnames[i] = pstrdup(RelationGetRelationName(vacrel->indrels[i]));
+
+ /*
+ * Allocate space for workers usage statistics. Thus, we explicitly
+ * make clear that such statistics must be accumulated. For now, this
+ * is used only by autovacuum leader worker, because it must log it in
+ * the end of table processing.
+ */
+ vacrel->workers_usage = AmAutoVacuumWorkerProcess() ?
+ (PVWorkersUsage *) palloc0(sizeof(PVWorkersUsage)) :
+ NULL;
}
/*
@@ -1125,6 +1141,11 @@ 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)
+ appendStringInfo(&buf,
+ _("parallel index vacuum/cleanup : workers planned = %d, workers launched = %d\n"),
+ vacrel->workers_usage->nplanned,
+ vacrel->workers_usage->nlaunched);
for (int i = 0; i < vacrel->nindexes; i++)
{
IndexBulkDeleteResult *istat = vacrel->indstats[i];
@@ -2700,7 +2721,8 @@ 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
@@ -3133,7 +3155,8 @@ 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 6a3a00585f9..490f93959d1 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;
@@ -742,6 +743,13 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
"launched %d parallel vacuum workers for index cleanup (planned: %d)",
pvs->pcxt->nworkers_launched),
pvs->pcxt->nworkers_launched, nworkers)));
+
+ /* Remember these values, if we asked to. */
+ if (wusage != NULL)
+ {
+ wusage->nlaunched += pvs->pcxt->nworkers_launched;
+ wusage->nplanned += nworkers;
+ }
}
/* Vacuum the indexes that can be processed by only leader process */
diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h
index e885a4b9c77..ec5d70aacdc 100644
--- a/src/include/commands/vacuum.h
+++ b/src/include/commands/vacuum.h
@@ -300,6 +300,16 @@ typedef struct VacDeadItemsInfo
int64 num_items; /* current # of entries */
} VacDeadItemsInfo;
+/*
+ * PVWorkersUsage stores information about total number of launched and planned
+ * workers during parallel vacuum.
+ */
+typedef struct PVWorkersUsage
+{
+ int nlaunched;
+ int nplanned;
+} PVWorkersUsage;
+
/* GUC parameters */
extern PGDLLIMPORT int default_statistics_target; /* PGDLLIMPORT for PostGIS */
extern PGDLLIMPORT int vacuum_freeze_min_age;
@@ -394,11 +404,13 @@ 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 b9e671fcda8..6e35c6aa493 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2397,6 +2397,7 @@ PullFilterOps
PushFilter
PushFilterOps
PushFunction
+PVWorkersUsage
PyCFunction
PyMethodDef
PyModuleDef
--
2.43.0
From 6f615b06b1578b5c72b36074de20811999b52e4f Mon Sep 17 00:00:00 2001
From: Daniil Davidov <[email protected]>
Date: Sun, 23 Nov 2025 02:32:44 +0700
Subject: [PATCH v17 4/4] 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 601aa3afb8e..36fcc72f325 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -2847,6 +2847,7 @@ 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>
@@ -9282,6 +9283,22 @@ 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 ca52efb09b02d21f6e35dabed2b9563d851151a0 Mon Sep 17 00:00:00 2001
From: Daniil Davidov <[email protected]>
Date: Sun, 23 Nov 2025 01:08:14 +0700
Subject: [PATCH v17 3/4] Tests for parallel autovacuum
---
src/backend/commands/vacuumparallel.c | 8 +
src/backend/postmaster/autovacuum.c | 14 +
src/test/modules/Makefile | 1 +
src/test/modules/meson.build | 1 +
src/test/modules/test_autovacuum/.gitignore | 2 +
src/test/modules/test_autovacuum/Makefile | 26 ++
src/test/modules/test_autovacuum/meson.build | 36 +++
.../modules/test_autovacuum/t/001_basic.pl | 165 ++++++++++++
.../test_autovacuum/test_autovacuum--1.0.sql | 34 +++
.../modules/test_autovacuum/test_autovacuum.c | 255 ++++++++++++++++++
.../test_autovacuum/test_autovacuum.control | 3 +
11 files changed, 545 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 490f93959d1..c2f0a37eef2 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"
@@ -752,6 +753,13 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
}
}
+ /*
+ * To be able to exercise whether all reserved parallel workers are being
+ * released anyway, allow injection points to trigger a failure at this
+ * point.
+ */
+ INJECTION_POINT("autovacuum-trigger-leader-failure", NULL);
+
/* Vacuum the indexes that can be processed by only leader process */
parallel_vacuum_process_unsafe_indexes(pvs);
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index bc11970bfee..a27274bfb4d 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -3439,6 +3439,13 @@ AutoVacuumReserveParallelWorkers(int *nworkers)
/* Remember how many workers we have reserved. */
av_nworkers_reserved = *nworkers;
+ /*
+ * Injection point to help exercising number of available parallel
+ * autovacuum workers.
+ */
+ INJECTION_POINT("autovacuum-set-free-parallel-workers-num",
+ &AutoVacuumShmem->av_freeParallelWorkers);
+
LWLockRelease(AutovacuumLock);
}
@@ -3468,6 +3475,13 @@ AutoVacuumReleaseParallelWorkers(int nworkers)
/* Don't have to remember these workers anymore. */
av_nworkers_reserved -= nworkers;
+ /*
+ * Injection point to help exercising number of available parallel
+ * autovacuum workers.
+ */
+ INJECTION_POINT("autovacuum-set-free-parallel-workers-num",
+ &AutoVacuumShmem->av_freeParallelWorkers);
+
LWLockRelease(AutovacuumLock);
}
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..4cf7344b2ac
--- /dev/null
+++ b/src/test/modules/test_autovacuum/Makefile
@@ -0,0 +1,26 @@
+# 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
+
+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..1271768ebd2
--- /dev/null
+++ b/src/test/modules/test_autovacuum/t/001_basic.pl
@@ -0,0 +1,165 @@
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+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
+$node->append_conf('postgresql.conf', qq{
+ max_worker_processes = 20
+ max_parallel_workers = 20
+ max_parallel_maintenance_workers = 20
+ autovacuum_max_parallel_workers = 10
+ log_min_messages = debug2
+ log_autovacuum_min_duration = 0
+ autovacuum_naptime = '1s'
+ min_parallel_index_scan_size = 0
+ shared_preload_libraries=test_autovacuum
+});
+$node->start;
+
+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 = $autovacuum_parallel_workers,
+ autovacuum_enabled = false);
+
+ DO \$\$
+ DECLARE
+ i INTEGER;
+ BEGIN
+ FOR i IN 1..$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 \$\$;
+});
+
+# Now, create some dead tuples and refresh table statistics
+$node->safe_psql('postgres', qq{
+ UPDATE test_autovac SET col_1 = 0 WHERE (col_1 % 3) = 0;
+ ANALYZE test_autovac;
+});
+
+# Create all functions needed for testing
+$node->safe_psql('postgres', qq{
+ CREATE EXTENSION test_autovacuum;
+ SELECT inj_set_free_workers_attach();
+ SELECT inj_leader_failure_attach();
+});
+
+# 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
+
+$node->safe_psql('postgres', qq{
+ ALTER TABLE test_autovac SET (autovacuum_enabled = true);
+});
+
+# Wait until the parallel autovacuum on table is completed. At the same time,
+# we check that the required number of parallel workers has been started.
+$node->wait_for_log(qr/parallel index vacuum\/cleanup : workers planned = 2, / .
+ qr/workers launched = 2/);
+
+$node->psql('postgres',
+ "SELECT get_parallel_autovacuum_free_workers();",
+ stdout => \$psql_out,
+);
+is($psql_out, 10, 'All parallel workers has been released by the leader');
+
+# Disable autovacuum on table during preparation for the next test
+$node->append_conf('postgresql.conf', qq{
+ ALTER TABLE test_autovac SET (autovacuum_enabled = false);
+});
+
+# Create more dead tuples
+$node->safe_psql('postgres', qq{
+ UPDATE test_autovac SET col_2 = 0 WHERE (col_2 % 3) = 0;
+ ANALYZE test_autovac;
+});
+
+# Test 2:
+# 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.
+
+$node->safe_psql('postgres', qq(
+ SELECT trigger_leader_failure('ERROR');
+));
+
+$node->safe_psql('postgres', qq{
+ ALTER TABLE test_autovac SET (autovacuum_enabled = true);
+});
+
+$node->wait_for_log(qr/error, triggered by injection point/);
+
+$node->psql('postgres',
+ "SELECT get_parallel_autovacuum_free_workers();",
+ stdout => \$psql_out,
+);
+is($psql_out, 10,
+ 'All parallel workers has been released by the leader after ERROR');
+
+# Disable autovacuum on table during preparation for the next test
+$node->append_conf('postgresql.conf', qq{
+ ALTER TABLE test_autovac SET (autovacuum_enabled = false);
+});
+
+# Create more dead tuples
+$node->safe_psql('postgres', qq{
+ UPDATE test_autovac SET col_3 = 0 WHERE (col_3 % 3) = 0;
+ ANALYZE test_autovac;
+});
+
+# Test 3:
+# Same as Test 2, but simulate situation, when leader exites due to FATAL.
+
+$node->safe_psql('postgres', qq(
+ SELECT trigger_leader_failure('FATAL');
+));
+
+$node->safe_psql('postgres', qq{
+ ALTER TABLE test_autovac SET (autovacuum_enabled = true);
+});
+
+$node->wait_for_log(qr/fatal, triggered by injection point/);
+
+$node->psql('postgres',
+ "SELECT get_parallel_autovacuum_free_workers();",
+ stdout => \$psql_out,
+);
+is($psql_out, 10,
+ 'All parallel workers has been released by the leader after FATAL');
+
+# Cleanup
+$node->safe_psql('postgres', qq{
+ SELECT inj_set_free_workers_detach();
+ SELECT inj_leader_failure_detach();
+});
+
+$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..017d5da85ea
--- /dev/null
+++ b/src/test/modules/test_autovacuum/test_autovacuum--1.0.sql
@@ -0,0 +1,34 @@
+/* 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 or to interfere autovacuum state
+ */
+CREATE FUNCTION get_parallel_autovacuum_free_workers()
+RETURNS INTEGER STRICT
+AS 'MODULE_PATHNAME' LANGUAGE C;
+
+CREATE FUNCTION trigger_leader_failure(failure_type text)
+RETURNS VOID STRICT
+AS 'MODULE_PATHNAME' LANGUAGE C;
+
+/*
+ * Injection point related functions
+ */
+CREATE FUNCTION inj_set_free_workers_attach()
+RETURNS VOID STRICT
+AS 'MODULE_PATHNAME' LANGUAGE C;
+
+CREATE FUNCTION inj_set_free_workers_detach()
+RETURNS VOID STRICT
+AS 'MODULE_PATHNAME' LANGUAGE C;
+
+CREATE FUNCTION inj_leader_failure_attach()
+RETURNS VOID STRICT
+AS 'MODULE_PATHNAME' LANGUAGE C;
+
+CREATE FUNCTION inj_leader_failure_detach()
+RETURNS VOID 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..7948f4858ae
--- /dev/null
+++ b/src/test/modules/test_autovacuum/test_autovacuum.c
@@ -0,0 +1,255 @@
+/*-------------------------------------------------------------------------
+ *
+ * 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 "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;
+
+typedef enum AVLeaderFaulureType
+{
+ FAIL_NONE,
+ FAIL_ERROR,
+ FAIL_FATAL,
+} AVLeaderFaulureType;
+
+typedef struct InjPointState
+{
+ bool enabled_set_free_workers;
+ uint32 free_parallel_workers;
+
+ bool enabled_leader_failure;
+ AVLeaderFaulureType ftype;
+} InjPointState;
+
+static InjPointState * inj_point_state;
+
+/* Shared memory init callbacks */
+static shmem_request_hook_type prev_shmem_request_hook = NULL;
+static shmem_startup_hook_type prev_shmem_startup_hook = NULL;
+
+static void
+test_autovacuum_shmem_request(void)
+{
+ if (prev_shmem_request_hook)
+ prev_shmem_request_hook();
+
+ RequestAddinShmemSpace(sizeof(InjPointState));
+}
+
+static void
+test_autovacuum_shmem_startup(void)
+{
+ bool found;
+
+ if (prev_shmem_startup_hook)
+ prev_shmem_startup_hook();
+
+ /* Create or attach to the shared memory state */
+ LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
+
+ inj_point_state = ShmemInitStruct("injection_points",
+ sizeof(InjPointState),
+ &found);
+
+ if (!found)
+ {
+ /* First time through, initialize */
+ inj_point_state->enabled_leader_failure = false;
+ inj_point_state->enabled_set_free_workers = false;
+ inj_point_state->ftype = FAIL_NONE;
+
+ /* Keep it in sync with AutoVacuumShmemInit */
+ inj_point_state->free_parallel_workers =
+ Min(autovacuum_max_parallel_workers, max_worker_processes);
+
+ InjectionPointAttach("autovacuum-set-free-parallel-workers-num",
+ "test_autovacuum",
+ "inj_set_free_workers",
+ NULL,
+ 0);
+
+ InjectionPointAttach("autovacuum-trigger-leader-failure",
+ "test_autovacuum",
+ "inj_trigger_leader_failure",
+ NULL,
+ 0);
+ }
+
+ LWLockRelease(AddinShmemInitLock);
+}
+
+void
+_PG_init(void)
+{
+ if (!process_shared_preload_libraries_in_progress)
+ return;
+
+ prev_shmem_request_hook = shmem_request_hook;
+ shmem_request_hook = test_autovacuum_shmem_request;
+ prev_shmem_startup_hook = shmem_startup_hook;
+ shmem_startup_hook = test_autovacuum_shmem_startup;
+}
+
+extern PGDLLEXPORT void inj_set_free_workers(const char *name,
+ const void *private_data,
+ void *arg);
+extern PGDLLEXPORT void inj_trigger_leader_failure(const char *name,
+ const void *private_data,
+ void *arg);
+
+/*
+ * Set number of currently available parallel a/v workers. This value may
+ * change after reserving or releasing such workers.
+ *
+ * Function called from parallel autovacuum leader.
+ */
+void
+inj_set_free_workers(const char *name, const void *private_data, void *arg)
+{
+ ereport(LOG,
+ errmsg("set parallel workers injection point called"),
+ errhidestmt(true), errhidecontext(true));
+
+ if (inj_point_state->enabled_set_free_workers)
+ {
+ Assert(arg != NULL);
+ inj_point_state->free_parallel_workers = *(uint32 *) arg;
+ }
+}
+
+/*
+ * Throw an ERROR or FATAL, if somebody requested it.
+ *
+ * Function called from parallel autovacuum leader.
+ */
+void
+inj_trigger_leader_failure(const char *name, const void *private_data,
+ void *arg)
+{
+ int elevel;
+ char *elevel_str;
+
+ ereport(LOG,
+ errmsg("trigger leader failure injection point called"),
+ errhidestmt(true), errhidecontext(true));
+
+ if (inj_point_state->ftype == FAIL_NONE ||
+ !inj_point_state->enabled_leader_failure)
+ {
+ return;
+ }
+
+ elevel = inj_point_state->ftype == FAIL_ERROR ? ERROR : FATAL;
+ elevel_str = elevel == ERROR ? "error" : "fatal";
+
+ ereport(elevel, errmsg("%s, triggered by injection point", elevel_str));
+}
+
+PG_FUNCTION_INFO_V1(get_parallel_autovacuum_free_workers);
+Datum
+get_parallel_autovacuum_free_workers(PG_FUNCTION_ARGS)
+{
+ uint32 nworkers;
+
+#ifndef USE_INJECTION_POINTS
+ elog(ERROR, "injection points not supported");
+#endif
+
+ LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
+ nworkers = inj_point_state->free_parallel_workers;
+ LWLockRelease(AutovacuumLock);
+
+ PG_RETURN_UINT32(nworkers);
+}
+
+PG_FUNCTION_INFO_V1(trigger_leader_failure);
+Datum
+trigger_leader_failure(PG_FUNCTION_ARGS)
+{
+ const char *failure_type = text_to_cstring(PG_GETARG_TEXT_PP(0));
+
+#ifndef USE_INJECTION_POINTS
+ elog(ERROR, "injection points not supported");
+#endif
+
+ if (strcmp(failure_type, "NONE") == 0)
+ inj_point_state->ftype = FAIL_NONE;
+ else if (strcmp(failure_type, "ERROR") == 0)
+ inj_point_state->ftype = FAIL_ERROR;
+ else if (strcmp(failure_type, "FATAL") == 0)
+ inj_point_state->ftype = FAIL_FATAL;
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("invalid leader failure type : %s", failure_type)));
+
+ PG_RETURN_VOID();
+}
+
+PG_FUNCTION_INFO_V1(inj_set_free_workers_attach);
+Datum
+inj_set_free_workers_attach(PG_FUNCTION_ARGS)
+{
+#ifdef USE_INJECTION_POINTS
+ inj_point_state->enabled_set_free_workers = true;
+ inj_point_state->ftype = FAIL_NONE;
+#else
+ elog(ERROR, "injection points not supported");
+#endif
+ PG_RETURN_VOID();
+}
+
+PG_FUNCTION_INFO_V1(inj_set_free_workers_detach);
+Datum
+inj_set_free_workers_detach(PG_FUNCTION_ARGS)
+{
+#ifdef USE_INJECTION_POINTS
+ inj_point_state->enabled_set_free_workers = false;
+#else
+ elog(ERROR, "injection points not supported");
+#endif
+ PG_RETURN_VOID();
+}
+
+PG_FUNCTION_INFO_V1(inj_leader_failure_attach);
+Datum
+inj_leader_failure_attach(PG_FUNCTION_ARGS)
+{
+#ifdef USE_INJECTION_POINTS
+ inj_point_state->enabled_leader_failure = true;
+#else
+ elog(ERROR, "injection points not supported");
+#endif
+ PG_RETURN_VOID();
+}
+
+PG_FUNCTION_INFO_V1(inj_leader_failure_detach);
+Datum
+inj_leader_failure_detach(PG_FUNCTION_ARGS)
+{
+#ifdef USE_INJECTION_POINTS
+ inj_point_state->enabled_leader_failure = false;
+#else
+ elog(ERROR, "injection points not supported");
+#endif
+ PG_RETURN_VOID();
+}
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 a5f261dc7b4fe37aba8f24ef5241e2b1f2d85a36 Mon Sep 17 00:00:00 2001
From: Daniil Davidov <[email protected]>
Date: Sun, 23 Nov 2025 01:03:24 +0700
Subject: [PATCH v17 1/4] Parallel autovacuum
---
src/backend/access/common/reloptions.c | 11 ++
src/backend/commands/vacuumparallel.c | 42 ++++-
src/backend/postmaster/autovacuum.c | 166 +++++++++++++++++-
src/backend/utils/init/globals.c | 1 +
src/backend/utils/misc/guc.c | 8 +-
src/backend/utils/misc/guc_parameters.dat | 9 +
src/backend/utils/misc/postgresql.conf.sample | 2 +
src/bin/psql/tab-complete.in.c | 1 +
src/include/miscadmin.h | 1 +
src/include/postmaster/autovacuum.h | 4 +
src/include/utils/rel.h | 7 +
11 files changed, 242 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..6a3a00585f9 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 +706,16 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
LaunchParallelWorkers(pvs->pcxt);
+ if (AmAutoVacuumWorkerProcess() &&
+ pvs->pcxt->nworkers_launched < nworkers)
+ {
+ /*
+ * Tell autovacuum that we could not launch all the previously
+ * reserved workers.
+ */
+ AutoVacuumReleaseParallelWorkers(nworkers - pvs->pcxt->nworkers_launched);
+ }
+
if (pvs->pcxt->nworkers_launched > 0)
{
/*
@@ -738,6 +764,10 @@ 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]);
+
+ /* Also release all previously reserved parallel autovacuum workers */
+ if (AmAutoVacuumWorkerProcess() && pvs->pcxt->nworkers_launched > 0)
+ AutoVacuumReleaseParallelWorkers(pvs->pcxt->nworkers_launched);
}
/*
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 3e507d23cc9..bc11970bfee 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -151,6 +151,12 @@ int Log_autoanalyze_min_duration = 600000;
static double av_storage_param_cost_delay = -1;
static int av_storage_param_cost_limit = -1;
+/*
+ * Variable to keep number of currently reserved parallel autovacuum workers.
+ * It is only relevant for 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 +291,8 @@ 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 +307,8 @@ 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;
@@ -364,6 +374,8 @@ 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);
+static void AutoVacuumReleaseAllParallelWorkers(void);
@@ -763,6 +775,8 @@ 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);
@@ -779,6 +793,15 @@ 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);
}
@@ -1383,6 +1406,19 @@ 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)
+{
+ if (code != 0)
+ AutoVacuumReleaseAllParallelWorkers();
+
+ Assert(av_nworkers_reserved == 0);
+}
+
/*
* Main entry point for autovacuum worker processes.
*/
@@ -1438,6 +1474,8 @@ AutoVacWorkerMain(const void *startup_data, size_t startup_data_len)
/* Early initialization */
BaseInit();
+ before_shmem_exit(autovacuum_worker_before_shmem_exit, 0);
+
/*
* If an exception is encountered, processing resumes here.
*
@@ -2480,6 +2518,12 @@ 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.
@@ -2880,8 +2924,12 @@ 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;
@@ -3358,6 +3406,85 @@ AutoVacuumRequestWork(AutoVacuumWorkItemType type, Oid relationId,
return result;
}
+/*
+ * In order to meet the 'autovacuum_max_parallel_workers' limit, leader
+ * autovacuum process must call this function during computing the parallel
+ * degree.
+ *
+ * 'nworkers' is the desired number of parallel workers to reserve. Function
+ * sets 'nworkers' to the number of parallel workers that actually can be
+ * launched and reserves these workers (if any) in global autovacuum state.
+ *
+ * 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 worker can call this function. */
+ Assert(AmAutoVacuumWorkerProcess() && !IsParallelWorker());
+
+ /*
+ * We can only reserve workers at the beginning of parallel index
+ * processing, so we must not have any reserved workers right now.
+ */
+ 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;
+
+ /* Remember how many workers we have reserved. */
+ av_nworkers_reserved = *nworkers;
+
+ LWLockRelease(AutovacuumLock);
+}
+
+/*
+ * Leader autovacuum process must call this function in order to update global
+ * autovacuum state, so other leaders will be able to use these parallel
+ * workers.
+ *
+ * 'nworkers' - how many workers caller wants to release.
+ */
+void
+AutoVacuumReleaseParallelWorkers(int nworkers)
+{
+ /* Only leader worker can call this function. */
+ Assert(AmAutoVacuumWorkerProcess() && !IsParallelWorker());
+
+ 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);
+
+ /* Don't have to remember these workers anymore. */
+ av_nworkers_reserved -= nworkers;
+
+ LWLockRelease(AutovacuumLock);
+}
+
+/*
+ * Same as above, but release *all* parallel workers, that were reserved by
+ * current leader autovacuum process.
+ */
+static void
+AutoVacuumReleaseAllParallelWorkers(void)
+{
+ /* Only leader worker can call this function. */
+ Assert(AmAutoVacuumWorkerProcess() && !IsParallelWorker());
+
+ if (av_nworkers_reserved > 0)
+ AutoVacuumReleaseParallelWorkers(av_nworkers_reserved);
+}
+
/*
* autovac_init
* This is called at postmaster initialization.
@@ -3418,6 +3545,10 @@ 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;
@@ -3499,3 +3630,34 @@ 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)));
}
+
+/*
+ * Make sure that number of free parallel workers corresponds to the
+ * autovacuum_max_parallel_workers parameter (after it was changed).
+ */
+static void
+adjust_free_parallel_workers(int prev_max_parallel_workers)
+{
+ LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
+
+ /*
+ * Cap the number of free workers by new parameter's value, if needed.
+ */
+ AutoVacuumShmem->av_freeParallelWorkers =
+ Min(AutoVacuumShmem->av_freeParallelWorkers,
+ autovacuum_max_parallel_workers);
+
+ if (autovacuum_max_parallel_workers > prev_max_parallel_workers)
+ {
+ /*
+ * If user wants to increase number of parallel autovacuum workers, we
+ * must increase number of free workers.
+ */
+ AutoVacuumShmem->av_freeParallelWorkers +=
+ (autovacuum_max_parallel_workers - prev_max_parallel_workers);
+ }
+
+ 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..24ddb276f0c 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 = 0;
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..e933f5048f7 100644
--- a/src/backend/utils/misc/guc_parameters.dat
+++ b/src/backend/utils/misc/guc_parameters.dat
@@ -154,6 +154,15 @@
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.',
+ long_desc => 'This parameter is capped by "max_worker_processes" (not by "autovacuum_max_workers"!).',
+ 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..86c67b790b0 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -691,6 +691,8 @@
#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 # disabled by default and 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 06edea98f06..2b8a4aab390 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 e43067d0260..4acadbc0610 100644
--- a/src/include/postmaster/autovacuum.h
+++ b/src/include/postmaster/autovacuum.h
@@ -65,6 +65,10 @@ 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);
+
/* 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
