Hi,
On Wed, Jun 18, 2025 at 5:37 AM Masahiko Sawada <sawada.m...@gmail.com> wrote:
>
> On Sun, May 25, 2025 at 10:22 AM Daniil Davydov <3daniss...@gmail.com> wrote:
> >
> > Thanks everybody for feedback! I attach a v4 patch to this letter.
> > Main features :
> > 1) 'parallel_autovacuum_workers' reloption - integer value, that sets
> > the maximum number of parallel a/v workers that can be taken from
> > bgworkers pool in order to process this table.
> > 2) 'max_parallel_autovacuum_workers' - GUC variable, that sets the
> > maximum total number of parallel a/v workers, that can be taken from
> > bgworkers pool.
> > 3) Parallel autovacuum does not try to use thresholds like
> > NUM_INDEXES_PER_PARALLEL_WORKER and AV_PARALLEL_DEADTUP_THRESHOLD.
> > 4) Parallel autovacuum now can report statistics like "planned vs.
> > launched".
> > 5) For now I got rid of the 'reserving' idea, so now autovacuum
> > leaders are competing with everyone for parallel workers from the
> > bgworkers pool.
> >
> > What do you think about this implementation?
> >
>
> I think it basically makes sense to me. A few comments:
>
> ---
> The patch implements max_parallel_autovacuum_workers as a
> PGC_POSTMASTER parameter but can we make it PGC_SIGHUP? I think we
> don't necessarily need to make it a PGC_POSTMATER since it actually
> doesn't affect how much shared memory we need to allocate.
>
Yep, there's nothing stopping us from doing that. This is a usable
feature, I'll implement it in the v5 patch.
> ---
> I think it's better to have the prefix "autovacuum" for the new GUC
> parameter for better consistency with other autovacuum-related GUC
> parameters.
>
> ---
> #include "storage/spin.h"
> @@ -514,6 +515,11 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
> {
> WaitForParallelWorkersToFinish(pcxt);
> WaitForParallelWorkersToExit(pcxt);
> +
> + /* Release all launched (i.e. reserved) parallel autovacuum workers.
> */
> + if (AmAutoVacuumWorkerProcess())
> + ParallelAutoVacuumReleaseWorkers(pcxt->nworkers_launched);
> +
> pcxt->nworkers_launched = 0;
> if (pcxt->known_attached_workers)
> {
> @@ -1002,6 +1008,11 @@ DestroyParallelContext(ParallelContext *pcxt)
> */
> HOLD_INTERRUPTS();
> WaitForParallelWorkersToExit(pcxt);
> +
> + /* Release all launched (i.e. reserved) parallel autovacuum workers. */
> + if (AmAutoVacuumWorkerProcess())
> + ParallelAutoVacuumReleaseWorkers(pcxt->nworkers_launched);
> +
> RESUME_INTERRUPTS();
>
> I think that it's better to release workers in vacuumparallel.c rather
> than parallel.c.
>
Agree with both comments.
Thanks for the review! Please, see v5 patch :
1) GUC variable and field in autovacuum shmem are renamed
2) ParallelAutoVacuumReleaseWorkers call moved from parallel.c to
vacuumparallel.c
3) max_parallel_autovacuum_workers is now PGC_SIGHUP parameter
4) Fix little bug (ParallelAutoVacuumReleaseWorkers in autovacuum.c:735)
--
Best regards,
Daniil Davydov
From 144c2dfda58103638435bccc55e8fe8d27dd1fad Mon Sep 17 00:00:00 2001
From: Daniil Davidov <d.davy...@postgrespro.ru>
Date: Fri, 16 May 2025 11:59:03 +0700
Subject: [PATCH v5 2/2] Sandbox for parallel index autovacuum
---
src/test/modules/Makefile | 1 +
src/test/modules/autovacuum/.gitignore | 1 +
src/test/modules/autovacuum/Makefile | 14 ++
src/test/modules/autovacuum/meson.build | 12 ++
.../autovacuum/t/001_autovac_parallel.pl | 131 ++++++++++++++++++
src/test/modules/meson.build | 1 +
6 files changed, 160 insertions(+)
create mode 100644 src/test/modules/autovacuum/.gitignore
create mode 100644 src/test/modules/autovacuum/Makefile
create mode 100644 src/test/modules/autovacuum/meson.build
create mode 100644 src/test/modules/autovacuum/t/001_autovac_parallel.pl
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index aa1d27bbed3..b7f3e342e82 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -5,6 +5,7 @@ top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
SUBDIRS = \
+ autovacuum \
brin \
commit_ts \
delay_execution \
diff --git a/src/test/modules/autovacuum/.gitignore b/src/test/modules/autovacuum/.gitignore
new file mode 100644
index 00000000000..0b54641bceb
--- /dev/null
+++ b/src/test/modules/autovacuum/.gitignore
@@ -0,0 +1 @@
+/tmp_check/
\ No newline at end of file
diff --git a/src/test/modules/autovacuum/Makefile b/src/test/modules/autovacuum/Makefile
new file mode 100644
index 00000000000..90c00ff350b
--- /dev/null
+++ b/src/test/modules/autovacuum/Makefile
@@ -0,0 +1,14 @@
+# src/test/modules/autovacuum/Makefile
+
+TAP_TESTS = 1
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/autovacuum
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
\ No newline at end of file
diff --git a/src/test/modules/autovacuum/meson.build b/src/test/modules/autovacuum/meson.build
new file mode 100644
index 00000000000..f91c1a14d2b
--- /dev/null
+++ b/src/test/modules/autovacuum/meson.build
@@ -0,0 +1,12 @@
+# Copyright (c) 2022-2025, PostgreSQL Global Development Group
+
+tests += {
+ 'name': 'autovacuum',
+ 'sd': meson.current_source_dir(),
+ 'bd': meson.current_build_dir(),
+ 'tap': {
+ 'tests': [
+ 't/001_autovac_parallel.pl',
+ ],
+ },
+}
diff --git a/src/test/modules/autovacuum/t/001_autovac_parallel.pl b/src/test/modules/autovacuum/t/001_autovac_parallel.pl
new file mode 100644
index 00000000000..ae892e5b4de
--- /dev/null
+++ b/src/test/modules/autovacuum/t/001_autovac_parallel.pl
@@ -0,0 +1,131 @@
+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;
+$node->append_conf('postgresql.conf', qq{
+ autovacuum = off
+ max_wal_size = 4096
+ max_worker_processes = 20
+ max_parallel_workers = 20
+ max_parallel_maintenance_workers = 20
+ autovacuum_max_parallel_workers = 10
+ log_min_messages = info
+});
+$node->start;
+
+my $indexes_num = 80;
+my $initial_rows_num = 100_000;
+my $parallel_autovacuum_workers = 5;
+
+# Create big table and create specified number of b-tree indexes on it
+$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, col_5 INTEGER,
+ col_6 INTEGER, col_7 INTEGER, col_8 INTEGER, col_9 INTEGER, col_10 INTEGER,
+ col_11 INTEGER, col_12 INTEGER, col_13 INTEGER, col_14 INTEGER, col_15 INTEGER,
+ col_16 INTEGER, col_17 INTEGER, col_18 INTEGER, col_19 INTEGER, col_20 INTEGER,
+ col_21 INTEGER, col_22 INTEGER, col_23 INTEGER, col_24 INTEGER, col_25 INTEGER,
+ col_26 INTEGER, col_27 INTEGER, col_28 INTEGER, col_29 INTEGER, col_30 INTEGER,
+ col_31 INTEGER, col_32 INTEGER, col_33 INTEGER, col_34 INTEGER, col_35 INTEGER,
+ col_36 INTEGER, col_37 INTEGER, col_38 INTEGER, col_39 INTEGER, col_40 INTEGER,
+ col_41 INTEGER, col_42 INTEGER, col_43 INTEGER, col_44 INTEGER, col_45 INTEGER,
+ col_46 INTEGER, col_47 INTEGER, col_48 INTEGER, col_49 INTEGER, col_50 INTEGER,
+ col_51 INTEGER, col_52 INTEGER, col_53 INTEGER, col_54 INTEGER, col_55 INTEGER,
+ col_56 INTEGER, col_57 INTEGER, col_58 INTEGER, col_59 INTEGER, col_60 INTEGER,
+ col_61 INTEGER, col_62 INTEGER, col_63 INTEGER, col_64 INTEGER, col_65 INTEGER,
+ col_66 INTEGER, col_67 INTEGER, col_68 INTEGER, col_69 INTEGER, col_70 INTEGER,
+ col_71 INTEGER, col_72 INTEGER, col_73 INTEGER, col_74 INTEGER, col_75 INTEGER,
+ col_76 INTEGER, col_77 INTEGER, col_78 INTEGER, col_79 INTEGER, col_80 INTEGER,
+ col_81 INTEGER, col_82 INTEGER, col_83 INTEGER, col_84 INTEGER, col_85 INTEGER,
+ col_86 INTEGER, col_87 INTEGER, col_88 INTEGER, col_89 INTEGER, col_90 INTEGER,
+ col_91 INTEGER, col_92 INTEGER, col_93 INTEGER, col_94 INTEGER, col_95 INTEGER,
+ col_96 INTEGER, col_97 INTEGER, col_98 INTEGER, col_99 INTEGER, col_100 INTEGER
+ ) WITH (parallel_autovacuum_workers = $parallel_autovacuum_workers);
+
+ DO \$\$
+ DECLARE
+ i INTEGER;
+ BEGIN
+ FOR i IN 1..$indexes_num LOOP
+ EXECUTE format('CREATE INDEX idx_col_\%s ON test_autovac (col_\%s);', i, i);
+ END LOOP;
+ END \$\$;
+});
+
+$node->psql('postgres',
+ "SELECT COUNT(*) FROM pg_index i
+ JOIN pg_class c ON c.oid = i.indrelid
+ WHERE c.relname = 'test_autovac';",
+ stdout => \$psql_out
+);
+is($psql_out, $indexes_num + 1, "All indexes created successfully");
+
+$node->safe_psql('postgres', qq{
+ DO \$\$
+ DECLARE
+ i INTEGER;
+ BEGIN
+ FOR i IN 1..$initial_rows_num LOOP
+ INSERT INTO test_autovac (
+ col_1, col_2, col_3, col_4, col_5, col_6, col_7, col_8, col_9, col_10,
+ col_11, col_12, col_13, col_14, col_15, col_16, col_17, col_18, col_19, col_20,
+ col_21, col_22, col_23, col_24, col_25, col_26, col_27, col_28, col_29, col_30,
+ col_31, col_32, col_33, col_34, col_35, col_36, col_37, col_38, col_39, col_40,
+ col_41, col_42, col_43, col_44, col_45, col_46, col_47, col_48, col_49, col_50,
+ col_51, col_52, col_53, col_54, col_55, col_56, col_57, col_58, col_59, col_60,
+ col_61, col_62, col_63, col_64, col_65, col_66, col_67, col_68, col_69, col_70,
+ col_71, col_72, col_73, col_74, col_75, col_76, col_77, col_78, col_79, col_80,
+ col_81, col_82, col_83, col_84, col_85, col_86, col_87, col_88, col_89, col_90,
+ col_91, col_92, col_93, col_94, col_95, col_96, col_97, col_98, col_99, col_100
+ ) VALUES (
+ i, i + 1, i + 2, i + 3, i + 4, i + 5, i + 6, i + 7, i + 8, i + 9,
+ i + 10, i + 11, i + 12, i + 13, i + 14, i + 15, i + 16, i + 17, i + 18, i + 19,
+ i + 20, i + 21, i + 22, i + 23, i + 24, i + 25, i + 26, i + 27, i + 28, i + 29,
+ i + 30, i + 31, i + 32, i + 33, i + 34, i + 35, i + 36, i + 37, i + 38, i + 39,
+ i + 40, i + 41, i + 42, i + 43, i + 44, i + 45, i + 46, i + 47, i + 48, i + 49,
+ i + 50, i + 51, i + 52, i + 53, i + 54, i + 55, i + 56, i + 57, i + 58, i + 59,
+ i + 60, i + 61, i + 62, i + 63, i + 64, i + 65, i + 66, i + 67, i + 68, i + 69,
+ i + 70, i + 71, i + 72, i + 73, i + 74, i + 75, i + 76, i + 77, i + 78, i + 79,
+ i + 80, i + 81, i + 82, i + 83, i + 84, i + 85, i + 86, i + 87, i + 88, i + 89,
+ i + 90, i + 91, i + 92, i + 93, i + 94, i + 95, i + 96, i + 97, i + 98, i + 99
+ );
+ END LOOP;
+ END \$\$;
+});
+
+$node->psql('postgres',
+ "SELECT COUNT(*) FROM test_autovac;",
+ stdout => \$psql_out
+);
+is($psql_out, $initial_rows_num, "All data inserted into table successfully");
+
+$node->safe_psql('postgres', qq{
+ UPDATE test_autovac SET col_1 = 0 WHERE (col_1 % 3) = 0;
+ ANALYZE test_autovac;
+});
+
+# Reduce autovacuum_work_mem, so leader process will perform parallel indexi
+# vacuum phase several times
+$node->append_conf('postgresql.conf', qq{
+ autovacuum_naptime = '1s'
+ autovacuum_vacuum_threshold = 1
+ autovacuum_analyze_threshold = 1
+ autovacuum_vacuum_scale_factor = 0.1
+ autovacuum_analyze_scale_factor = 0.1
+ autovacuum = on
+});
+
+$node->restart;
+
+# sleep(3600);
+
+ok(1, "There are no segfaults");
+
+$node->stop;
+done_testing();
diff --git a/src/test/modules/meson.build b/src/test/modules/meson.build
index 9de0057bd1d..7f2ad810ca0 100644
--- a/src/test/modules/meson.build
+++ b/src/test/modules/meson.build
@@ -1,5 +1,6 @@
# Copyright (c) 2022-2025, PostgreSQL Global Development Group
+subdir('autovacuum')
subdir('brin')
subdir('commit_ts')
subdir('delay_execution')
--
2.43.0
From 88e55d49895ebc287213a415c242b4733cdecba8 Mon Sep 17 00:00:00 2001
From: Daniil Davidov <d.davy...@postgrespro.ru>
Date: Fri, 16 May 2025 11:58:40 +0700
Subject: [PATCH v5 1/2] Parallel index autovacuum with bgworkers
---
src/backend/access/common/reloptions.c | 12 ++
src/backend/access/heap/vacuumlazy.c | 6 +-
src/backend/commands/vacuumparallel.c | 93 ++++++++---
src/backend/postmaster/autovacuum.c | 144 +++++++++++++++++-
src/backend/utils/init/globals.c | 1 +
src/backend/utils/misc/guc_tables.c | 10 ++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/miscadmin.h | 1 +
src/include/postmaster/autovacuum.h | 4 +
src/include/utils/guc_hooks.h | 2 +
src/include/utils/rel.h | 12 ++
11 files changed, 259 insertions(+), 27 deletions(-)
diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index 50747c16396..e36d59f632b 100644
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -222,6 +222,16 @@ static relopt_int intRelOpts[] =
},
SPGIST_DEFAULT_FILLFACTOR, SPGIST_MIN_FILLFACTOR, 100
},
+ {
+ {
+ "parallel_autovacuum_workers",
+ "Maximum number of parallel autovacuum workers that can be taken from bgworkers pool for processing this table. "
+ "If value is 0 then parallel degree will computed based on number of indexes.",
+ RELOPT_KIND_HEAP,
+ ShareUpdateExclusiveLock
+ },
+ -1, -1, 1024
+ },
{
{
"autovacuum_vacuum_threshold",
@@ -1872,6 +1882,8 @@ 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)},
+ {"parallel_autovacuum_workers", RELOPT_TYPE_INT,
+ offsetof(StdRdOptions, autovacuum) + offsetof(AutoVacOpts, parallel_autovacuum_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/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 09416450af9..b89b1563444 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -3493,6 +3493,10 @@ dead_items_alloc(LVRelState *vacrel, int nworkers)
autovacuum_work_mem != -1 ?
autovacuum_work_mem : maintenance_work_mem;
+ int elevel = AmAutoVacuumWorkerProcess() ||
+ vacrel->verbose ?
+ INFO : DEBUG2;
+
/*
* Initialize state for a parallel vacuum. As of now, only one worker can
* be used for an index, so we invoke parallelism only if there are at
@@ -3519,7 +3523,7 @@ dead_items_alloc(LVRelState *vacrel, int nworkers)
vacrel->pvs = parallel_vacuum_init(vacrel->rel, vacrel->indrels,
vacrel->nindexes, nworkers,
vac_work_mem,
- vacrel->verbose ? INFO : DEBUG2,
+ elevel,
vacrel->bstrategy);
/*
diff --git a/src/backend/commands/vacuumparallel.c b/src/backend/commands/vacuumparallel.c
index 0feea1d30ec..bd314d23298 100644
--- a/src/backend/commands/vacuumparallel.c
+++ b/src/backend/commands/vacuumparallel.c
@@ -1,16 +1,16 @@
/*-------------------------------------------------------------------------
*
* vacuumparallel.c
- * Support routines for parallel vacuum execution.
+ * Support routines for parallel [auto]vacuum execution.
*
* This file contains routines that are intended to support setting up, using,
* and tearing down a ParallelVacuumState.
*
- * In a parallel vacuum, we perform both index bulk deletion and index cleanup
- * with parallel worker processes. Individual indexes are processed by one
- * vacuum process. ParallelVacuumState contains shared information as well as
- * the memory space for storing dead items allocated in the DSA area. We
- * launch parallel worker processes at the start of parallel index
+ * In a parallel [auto]vacuum, we perform both index bulk deletion and index
+ * cleanup with parallel worker processes. Individual indexes are processed by
+ * one [auto]vacuum process. ParallelVacuumState contains shared information
+ * as well as the memory space for storing dead items allocated in the DSA area.
+ * We launch parallel worker processes at the start of parallel index
* bulk-deletion and index cleanup and once all indexes are processed, the
* parallel worker processes exit. Each time we process indexes in parallel,
* the parallel context is re-initialized so that the same DSM can be used for
@@ -34,6 +34,7 @@
#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"
@@ -157,7 +158,8 @@ typedef struct PVIndStats
} PVIndStats;
/*
- * Struct for maintaining a parallel vacuum state. typedef appears in vacuum.h.
+ * Struct for maintaining a parallel [auto]vacuum state. typedef appears in
+ * vacuum.h.
*/
struct ParallelVacuumState
{
@@ -371,10 +373,18 @@ parallel_vacuum_init(Relation rel, Relation *indrels, int nindexes,
shared->relid = RelationGetRelid(rel);
shared->elevel = elevel;
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;
+
+ if (AmAutoVacuumWorkerProcess())
+ shared->maintenance_work_mem_worker =
+ (nindexes_mwm > 0) ?
+ autovacuum_work_mem / Min(parallel_workers, nindexes_mwm) :
+ autovacuum_work_mem;
+ else
+ shared->maintenance_work_mem_worker =
+ (nindexes_mwm > 0) ?
+ maintenance_work_mem / Min(parallel_workers, nindexes_mwm) :
+ maintenance_work_mem;
+
shared->dead_items_info.max_bytes = vac_work_mem * (size_t) 1024;
/* Prepare DSA space for dead items */
@@ -435,6 +445,8 @@ parallel_vacuum_init(Relation rel, Relation *indrels, int nindexes,
void
parallel_vacuum_end(ParallelVacuumState *pvs, IndexBulkDeleteResult **istats)
{
+ int nlaunched_workers;
+
Assert(!IsParallelWorker());
/* Copy the updated statistics */
@@ -453,7 +465,13 @@ parallel_vacuum_end(ParallelVacuumState *pvs, IndexBulkDeleteResult **istats)
TidStoreDestroy(pvs->dead_items);
+ nlaunched_workers = pvs->pcxt->nworkers_launched; /* remember this value */
DestroyParallelContext(pvs->pcxt);
+
+ /* Release all launched (i.e. reserved) parallel autovacuum workers. */
+ if (AmAutoVacuumWorkerProcess())
+ ParallelAutoVacuumReleaseWorkers(nlaunched_workers);
+
ExitParallelMode();
pfree(pvs->will_parallel_vacuum);
@@ -541,7 +559,7 @@ parallel_vacuum_cleanup_all_indexes(ParallelVacuumState *pvs, long num_table_tup
*
* nrequested is the number of parallel workers that user requested. If
* nrequested is 0, we compute the parallel degree based on nindexes, that is
- * the number of indexes that support parallel vacuum. This function also
+ * the number of indexes that support parallel [auto]vacuum. This function also
* sets will_parallel_vacuum to remember indexes that participate in parallel
* vacuum.
*/
@@ -558,7 +576,9 @@ parallel_vacuum_compute_workers(Relation *indrels, int nindexes, int nrequested,
* We don't allow performing parallel operation in standalone backend or
* when parallelism is disabled.
*/
- if (!IsUnderPostmaster || max_parallel_maintenance_workers == 0)
+ if (!IsUnderPostmaster ||
+ (autovacuum_max_parallel_workers == 0 && AmAutoVacuumWorkerProcess()) ||
+ (max_parallel_maintenance_workers == 0 && !AmAutoVacuumWorkerProcess()))
return 0;
/*
@@ -597,15 +617,17 @@ 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 = AmAutoVacuumWorkerProcess() ?
+ Min(parallel_workers, autovacuum_max_parallel_workers) :
+ Min(parallel_workers, max_parallel_maintenance_workers);
return parallel_workers;
}
/*
* Perform index vacuum or index cleanup with parallel workers. This function
- * must be used by the parallel vacuum leader process.
+ * must be used by the parallel [auto]vacuum leader process.
*/
static void
parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scans,
@@ -666,13 +688,26 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
/* Reset the parallel index processing and progress counters */
pg_atomic_write_u32(&(pvs->shared->idx), 0);
+ /* Check how many workers can provide autovacuum. */
+ if (AmAutoVacuumWorkerProcess() && nworkers > 0)
+ nworkers = ParallelAutoVacuumReserveWorkers(nworkers);
+
/* Setup the shared cost-based vacuum delay and launch workers */
if (nworkers > 0)
{
/* Reinitialize parallel context to relaunch parallel workers */
if (num_index_scans > 0)
+ {
ReinitializeParallelDSM(pvs->pcxt);
+ /*
+ * Release all launched (i.e. reserved) parallel autovacuum
+ * workers.
+ */
+ if (AmAutoVacuumWorkerProcess())
+ ParallelAutoVacuumReleaseWorkers(pvs->pcxt->nworkers_launched);
+ }
+
/*
* Set up shared cost balance and the number of active workers for
* vacuum delay. We need to do this before launching workers as
@@ -690,6 +725,16 @@ 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.
+ */
+ ParallelAutoVacuumReleaseWorkers(nworkers - pvs->pcxt->nworkers_launched);
+ }
+
if (pvs->pcxt->nworkers_launched > 0)
{
/*
@@ -706,16 +751,16 @@ parallel_vacuum_process_all_indexes(ParallelVacuumState *pvs, int num_index_scan
if (vacuum)
ereport(pvs->shared->elevel,
- (errmsg(ngettext("launched %d parallel vacuum worker for index vacuuming (planned: %d)",
- "launched %d parallel vacuum workers for index vacuuming (planned: %d)",
+ (errmsg(ngettext("launched %d parallel %svacuum worker for index vacuuming (planned: %d)",
+ "launched %d parallel %svacuum workers for index vacuuming (planned: %d)",
pvs->pcxt->nworkers_launched),
- pvs->pcxt->nworkers_launched, nworkers)));
+ pvs->pcxt->nworkers_launched, AmAutoVacuumWorkerProcess() ? "auto" : "", nworkers)));
else
ereport(pvs->shared->elevel,
- (errmsg(ngettext("launched %d parallel vacuum worker for index cleanup (planned: %d)",
- "launched %d parallel vacuum workers for index cleanup (planned: %d)",
+ (errmsg(ngettext("launched %d parallel %svacuum worker for index cleanup (planned: %d)",
+ "launched %d parallel %svacuum workers for index cleanup (planned: %d)",
pvs->pcxt->nworkers_launched),
- pvs->pcxt->nworkers_launched, nworkers)));
+ pvs->pcxt->nworkers_launched, AmAutoVacuumWorkerProcess() ? "auto" : "", nworkers)));
}
/* Vacuum the indexes that can be processed by only leader process */
@@ -982,8 +1027,8 @@ parallel_vacuum_index_is_parallel_safe(Relation indrel, int num_index_scans,
/*
* Perform work within a launched parallel process.
*
- * Since parallel vacuum workers perform only index vacuum or index cleanup,
- * we don't need to report progress information.
+ * Since parallel [auto]vacuum workers perform only index vacuum or index
+ * cleanup, we don't need to report progress information.
*/
void
parallel_vacuum_main(dsm_segment *seg, shm_toc *toc)
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 451fb90a610..60600b9ff52 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -285,6 +285,8 @@ 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_available_parallel_workers the number of available parallel autovacuum
+ * workers
*
* This struct is protected by AutovacuumLock, except for av_signal and parts
* of the worker list (see above).
@@ -299,6 +301,7 @@ typedef struct
WorkerInfo av_startingWorker;
AutoVacuumWorkItem av_workItems[NUM_WORKITEMS];
pg_atomic_uint32 av_nworkersForBalance;
+ uint32 av_available_parallel_workers;
} AutoVacuumShmemStruct;
static AutoVacuumShmemStruct *AutoVacuumShmem;
@@ -354,6 +357,7 @@ 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 check_parallel_av_gucs(int prev_max_parallel_workers);
@@ -753,7 +757,9 @@ ProcessAutoVacLauncherInterrupts(void)
if (ConfigReloadPending)
{
int autovacuum_max_workers_prev = autovacuum_max_workers;
+ int autovacuum_max_parallel_workers_prev;
+ autovacuum_max_parallel_workers_prev = autovacuum_max_parallel_workers;
ConfigReloadPending = false;
ProcessConfigFile(PGC_SIGHUP);
@@ -769,6 +775,14 @@ 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)
+ check_parallel_av_gucs(autovacuum_max_parallel_workers_prev);
+
/* rebuild the list in case the naptime changed */
rebuild_database_list(InvalidOid);
}
@@ -2847,8 +2861,12 @@ 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->parallel_autovacuum_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;
@@ -3329,6 +3347,72 @@ AutoVacuumRequestWork(AutoVacuumWorkItemType type, Oid relationId,
return result;
}
+/*
+ * In order to meet the 'max_parallel_autovacuum_workers' limit, leader worker
+ * must call this function. It returns the number of parallel workers that
+ * actually can be launched and reserves (if any) these workers in global
+ * autovacuum state.
+ *
+ * NOTE: We will try to provide as many workers as requested, even if caller
+ * will occupy all available workers.
+ */
+int
+ParallelAutoVacuumReserveWorkers(int nworkers)
+{
+ int can_launch;
+
+ /* Only leader worker can call this function. */
+ Assert(AmAutoVacuumWorkerProcess() && !IsParallelWorker());
+
+ LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
+ if (AutoVacuumShmem->av_available_parallel_workers < nworkers)
+ {
+ /* Provide as many workers as we can. */
+ can_launch = AutoVacuumShmem->av_available_parallel_workers;
+ AutoVacuumShmem->av_available_parallel_workers = 0;
+ }
+ else
+ {
+ /* OK, we can provide all requested workers. */
+ can_launch = nworkers;
+ AutoVacuumShmem->av_available_parallel_workers -= nworkers;
+ }
+ LWLockRelease(AutovacuumLock);
+
+ return can_launch;
+}
+
+/*
+ * When parallel autovacuum worker die, leader worker must call this function
+ * in order to refresh global autovacuum state. Thus, other leaders will be able
+ * to use these workers.
+ *
+ * 'nworkers' - how many workers caller wants to release.
+ */
+void
+ParallelAutoVacuumReleaseWorkers(int nworkers)
+{
+ /* Only leader worker can call this function. */
+ Assert(AmAutoVacuumWorkerProcess() && !IsParallelWorker());
+
+ LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
+ AutoVacuumShmem->av_available_parallel_workers += nworkers;
+
+ /*
+ * If autovacuum_max_parallel_workers variable was reduced during parallel
+ * autovacuum execution, we must cap available workers number by its new
+ * value.
+ */
+ if (AutoVacuumShmem->av_available_parallel_workers >
+ autovacuum_max_parallel_workers)
+ {
+ AutoVacuumShmem->av_available_parallel_workers =
+ autovacuum_max_parallel_workers;
+ }
+
+ LWLockRelease(AutovacuumLock);
+}
+
/*
* autovac_init
* This is called at postmaster initialization.
@@ -3389,6 +3473,8 @@ AutoVacuumShmemInit(void)
Assert(!found);
AutoVacuumShmem->av_launcherpid = 0;
+ AutoVacuumShmem->av_available_parallel_workers =
+ autovacuum_max_parallel_workers;
dclist_init(&AutoVacuumShmem->av_freeWorkers);
dlist_init(&AutoVacuumShmem->av_runningWorkers);
AutoVacuumShmem->av_startingWorker = NULL;
@@ -3439,6 +3525,15 @@ check_autovacuum_work_mem(int *newval, void **extra, GucSource source)
return true;
}
+bool
+check_autovacuum_max_parallel_workers(int *newval, void **extra,
+ GucSource source)
+{
+ if (*newval >= max_worker_processes)
+ return false;
+ return true;
+}
+
/*
* Returns whether there is a free autovacuum worker slot available.
*/
@@ -3470,3 +3565,48 @@ 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 available parallel workers corresponds to the
+ * autovacuum_max_parallel_workers parameter (after it was changed).
+ */
+static void
+check_parallel_av_gucs(int prev_max_parallel_workers)
+{
+ LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
+
+ if (AutoVacuumShmem->av_available_parallel_workers >
+ autovacuum_max_parallel_workers)
+ {
+ Assert(prev_max_parallel_workers > autovacuum_max_parallel_workers);
+
+ /*
+ * Number of available workers must not exeed limit.
+ *
+ * Note, that if some parallel autovacuum workers are running at this
+ * moment, available workers number will not exeed limit after releasing
+ * them (see ParallelAutoVacuumReleaseWorkers).
+ */
+ AutoVacuumShmem->av_available_parallel_workers =
+ autovacuum_max_parallel_workers;
+ }
+ else if ((AutoVacuumShmem->av_available_parallel_workers <
+ autovacuum_max_parallel_workers) &&
+ (autovacuum_max_parallel_workers > prev_max_parallel_workers))
+ {
+ /*
+ * If user wants to increase number of parallel autovacuum workers, we
+ * must increase number of available workers in shmem.
+ */
+ AutoVacuumShmem->av_available_parallel_workers +=
+ (autovacuum_max_parallel_workers - prev_max_parallel_workers);
+
+ /*
+ * Nothing to do when autovacuum_max_parallel_workers <
+ * prev_max_parallel_workers. Available workers number will be capped
+ * inside ParallelAutoVacuumReleaseWorkers.
+ */
+ }
+
+ LWLockRelease(AutovacuumLock);
+}
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index d31cb45a058..977644978c1 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_tables.c b/src/backend/utils/misc/guc_tables.c
index f04bfedb2fd..be76263c431 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -3604,6 +3604,16 @@ struct config_int ConfigureNamesInt[] =
NULL, NULL, NULL
},
+ {
+ {"autovacuum_max_parallel_workers", PGC_SIGHUP, VACUUM_AUTOVACUUM,
+ gettext_noop("Maximum number of parallel autovacuum workers, that can be taken from bgworkers pool."),
+ gettext_noop("This parameter is capped by \"max_worker_processes\" (not by \"autovacuum_max_workers\"!)."),
+ },
+ &autovacuum_max_parallel_workers,
+ 0, 0, MAX_BACKENDS,
+ check_autovacuum_max_parallel_workers, NULL, NULL
+ },
+
{
{"max_parallel_maintenance_workers", PGC_USERSET, RESOURCES_WORKER_PROCESSES,
gettext_noop("Sets the maximum number of parallel processes per maintenance operation."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 341f88adc87..f2b6ba7755e 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -683,6 +683,7 @@
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 = 0 # disabled by default and limited by max_parallel_workers
#autovacuum_naptime = 1min # time between autovacuum runs
#autovacuum_vacuum_threshold = 50 # min number of row updates before
# vacuum
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 1bef98471c3..85926415657 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -177,6 +177,7 @@ 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 e8135f41a1c..b5763e6ac36 100644
--- a/src/include/postmaster/autovacuum.h
+++ b/src/include/postmaster/autovacuum.h
@@ -64,6 +64,10 @@ 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 int ParallelAutoVacuumReserveWorkers(int nworkers);
+extern void ParallelAutoVacuumReleaseWorkers(int nworkers);
+
/* shared memory stuff */
extern Size AutoVacuumShmemSize(void);
extern void AutoVacuumShmemInit(void);
diff --git a/src/include/utils/guc_hooks.h b/src/include/utils/guc_hooks.h
index 799fa7ace68..5c66f37cd53 100644
--- a/src/include/utils/guc_hooks.h
+++ b/src/include/utils/guc_hooks.h
@@ -31,6 +31,8 @@ extern void assign_application_name(const char *newval, void *extra);
extern const char *show_archive_command(void);
extern bool check_autovacuum_work_mem(int *newval, void **extra,
GucSource source);
+extern bool check_autovacuum_max_parallel_workers(int *newval, void **extra,
+ GucSource source);
extern bool check_vacuum_buffer_usage_limit(int *newval, void **extra,
GucSource source);
extern bool check_backtrace_functions(char **newval, void **extra,
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index b552359915f..16091e6a773 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -311,6 +311,8 @@ typedef struct ForeignKeyCacheInfo
typedef struct AutoVacOpts
{
bool enabled;
+ int parallel_autovacuum_workers; /* max number of parallel
+ autovacuum workers */
int vacuum_threshold;
int vacuum_max_threshold;
int vacuum_ins_threshold;
@@ -409,6 +411,16 @@ typedef struct StdRdOptions
((relation)->rd_options ? \
((StdRdOptions *) (relation)->rd_options)->parallel_workers : (defaultpw))
+/*
+ * RelationGetParallelAutovacuumWorkers
+ * Returns the relation's parallel_autovacuum_workers reloption setting.
+ * Note multiple eval of argument!
+ */
+#define RelationGetParallelAutovacuumWorkers(relation, defaultpw) \
+ ((relation)->rd_options ? \
+ ((StdRdOptions *) (relation)->rd_options)->autovacuum.parallel_autovacuum_workers : \
+ (defaultpw))
+
/* ViewOptions->check_option values */
typedef enum ViewOptCheckOption
{
--
2.43.0
