In addition to adding several new tests, the attached version 26 fixes a
major bug in constructing the view.
The only valid combination of IOPATH/IOOP that is not tested now is
IOPATH_STRATEGY + IOOP_WRITE. In most cases when I ran this in regress,
the checkpointer wrote out the dirty strategy buffer before VACUUM got
around to reusing and writing it out in my tests.
I've also changed the BACKEND_NUM_TYPES definition. Now arrays will have
that dead spot for B_INVALID, but I feel like it is much easier to
understand without trying to skip that spot and use those special helper
functions.
I also started skipping adding rows to the view for WAL_RECEIVER and
WAL_WRITER and for BackendTypes except B_BACKEND and WAL_SENDER for
IOPATH_LOCAL.
On Tue, Jul 12, 2022 at 1:18 PM Andres Freund <and...@anarazel.de> wrote:
> On 2022-07-11 22:22:28 -0400, Melanie Plageman wrote:
> > Yes, per an off list suggestion by you, I have changed the tests to use a
> > sum of writes. I've also added a test for IOPATH_LOCAL and fixed some of
> > the missing calls to count IO Operations for IOPATH_LOCAL and
> > IOPATH_STRATEGY.
> >
> > I struggled to come up with a way to test writes for a particular
> > type of backend are counted correctly since a dirty buffer could be
> > written out by another type of backend before the target BackendType has
> > a chance to write it out.
>
> I guess temp file writes would be reliably done by one backend... Don't
> have a
> good idea otherwise.
>
>
This was mainly an issue for IOPATH_STRATEGY writes as I mentioned. I
still have not solved this.
>
> > I'm not sure how to cause a strategy "extend" for testing.
>
> COPY into a table should work. But might be unattractive due to the size
> of of
> the COPY ringbuffer.
>
Did it with a CTAS as Horiguchi-san suggested.
>
> > > Would be nice to have something testing that the ringbuffer stats stuff
> > > does something sensible - that feels not entirely trivial.
> > >
> > >
> > I've added a test to test that reused strategy buffers are counted as
> > allocs. I would like to add a test which checks that if a buffer in the
> > ring is pinned and thus not reused, that it is not counted as a strategy
> > alloc, but I found it challenging without a way to pause vacuuming, pin
> > a buffer, then resume vacuuming.
>
> Yea, that's probably too hard to make reliable to be worth it.
>
>
Yes, I have skipped this.
- Melanie
From f7772e4d19821e0aeb19e906ba6f5e4bb046cfdb Mon Sep 17 00:00:00 2001
From: Melanie Plageman <melanieplage...@gmail.com>
Date: Wed, 29 Jun 2022 18:37:42 -0400
Subject: [PATCH v26 3/4] Track IO operation statistics
Introduce "IOOp", an IO operation done by a backend, and "IOPath", the
location or type of IO done by a backend. For example, the checkpointer
may write a shared buffer out. This would be counted as an IOOp "write"
on an IOPath IOPATH_SHARED by BackendType "checkpointer".
Each IOOp (alloc, extend, fsync, read, write) is counted per IOPath
(local, shared, or strategy) through a call to pgstat_count_io_op().
The primary concern of these statistics is IO operations on data blocks
during the course of normal database operations. IO done by, for
example, the archiver or syslogger is not counted in these statistics.
IOPATH_LOCAL and IOPATH_SHARED IOPaths concern operations on local
and shared buffers.
The IOPATH_STRATEGY IOPath concerns buffers
alloc'd/extended/fsync'd/read/written as part of a BufferAccessStrategy.
IOOP_ALLOC is counted for IOPATH_SHARED and IOPATH_LOCAL whenever a
buffer is acquired through [Local]BufferAlloc(). IOOP_ALLOC for
IOPATH_STRATEGY is counted whenever a buffer already in the strategy
ring is reused. And IOOP_WRITE for IOPATH_STRATEGY is counted whenever
the reused dirty buffer is written out.
Stats on IOOps for all IOPaths for a backend are initially accumulated
locally.
Later they are flushed to shared memory and accumulated with those from
all other backends, exited and live. The accumulated stats in shared
memory could be extended in the future with per-backend stats -- useful
for per connection IO statistics and monitoring.
Some BackendTypes will not flush their pending statistics at regular
intervals and explicitly call pgstat_flush_io_ops() during the course of
normal operations to flush their backend-local IO Operation statistics
to shared memory in a timely manner.
Author: Melanie Plageman <melanieplage...@gmail.com>
Reviewed-by: Justin Pryzby <pry...@telsasoft.com>, Kyotaro Horiguchi <horikyota....@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/20200124195226.lth52iydq2n2uilq%40alap3.anarazel.de
---
src/backend/postmaster/checkpointer.c | 1 +
src/backend/storage/buffer/bufmgr.c | 53 ++++-
src/backend/storage/buffer/freelist.c | 25 ++-
src/backend/storage/buffer/localbuf.c | 5 +
src/backend/storage/sync/sync.c | 2 +
src/backend/utils/activity/Makefile | 1 +
src/backend/utils/activity/pgstat.c | 36 ++++
src/backend/utils/activity/pgstat_bgwriter.c | 7 +-
.../utils/activity/pgstat_checkpointer.c | 7 +-
src/backend/utils/activity/pgstat_io_ops.c | 193 ++++++++++++++++++
src/backend/utils/activity/pgstat_relation.c | 19 +-
src/backend/utils/activity/pgstat_wal.c | 4 +-
src/backend/utils/adt/pgstatfuncs.c | 4 +-
src/include/miscadmin.h | 2 +
src/include/pgstat.h | 58 ++++++
src/include/storage/buf_internals.h | 2 +-
src/include/utils/backend_status.h | 1 -
src/include/utils/pgstat_internal.h | 24 +++
18 files changed, 424 insertions(+), 20 deletions(-)
create mode 100644 src/backend/utils/activity/pgstat_io_ops.c
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index 5fc076fc14..a06331e1eb 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -1116,6 +1116,7 @@ ForwardSyncRequest(const FileTag *ftag, SyncRequestType type)
if (!AmBackgroundWriterProcess())
CheckpointerShmem->num_backend_fsync++;
LWLockRelease(CheckpointerCommLock);
+ pgstat_count_io_op(IOOP_FSYNC, IOPATH_SHARED);
return false;
}
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index c7d7abcd73..536d422df2 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -482,7 +482,7 @@ static BufferDesc *BufferAlloc(SMgrRelation smgr,
BlockNumber blockNum,
BufferAccessStrategy strategy,
bool *foundPtr);
-static void FlushBuffer(BufferDesc *buf, SMgrRelation reln);
+static void FlushBuffer(BufferDesc *buf, SMgrRelation reln, IOPath iopath);
static void FindAndDropRelationBuffers(RelFileLocator rlocator,
ForkNumber forkNum,
BlockNumber nForkBlock,
@@ -813,6 +813,7 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
BufferDesc *bufHdr;
Block bufBlock;
bool found;
+ IOPath io_path;
bool isExtend;
bool isLocalBuf = SmgrIsTemp(smgr);
@@ -978,8 +979,17 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
bufBlock = isLocalBuf ? LocalBufHdrGetBlock(bufHdr) : BufHdrGetBlock(bufHdr);
+ if (isLocalBuf)
+ io_path = IOPATH_LOCAL;
+ else if (strategy != NULL)
+ io_path = IOPATH_STRATEGY;
+ else
+ io_path = IOPATH_SHARED;
+
if (isExtend)
{
+
+ pgstat_count_io_op(IOOP_EXTEND, io_path);
/* new buffers are zero-filled */
MemSet((char *) bufBlock, 0, BLCKSZ);
/* don't set checksum for all-zero page */
@@ -1010,6 +1020,8 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
smgrread(smgr, forkNum, blockNum, (char *) bufBlock);
+ pgstat_count_io_op(IOOP_READ, io_path);
+
if (track_io_timing)
{
INSTR_TIME_SET_CURRENT(io_time);
@@ -1180,6 +1192,7 @@ BufferAlloc(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
/* Loop here in case we have to try another victim buffer */
for (;;)
{
+ bool from_ring;
/*
* Ensure, while the spinlock's not yet held, that there's a free
* refcount entry.
@@ -1190,7 +1203,7 @@ BufferAlloc(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
* Select a victim buffer. The buffer is returned with its header
* spinlock still held!
*/
- buf = StrategyGetBuffer(strategy, &buf_state);
+ buf = StrategyGetBuffer(strategy, &buf_state, &from_ring);
Assert(BUF_STATE_GET_REFCOUNT(buf_state) == 0);
@@ -1227,6 +1240,7 @@ BufferAlloc(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
if (LWLockConditionalAcquire(BufferDescriptorGetContentLock(buf),
LW_SHARED))
{
+ IOPath iopath;
/*
* If using a nondefault strategy, and writing the buffer
* would require a WAL flush, let the strategy decide whether
@@ -1253,13 +1267,27 @@ BufferAlloc(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
}
}
+ /*
+ * When a strategy is in use, if the target dirty buffer is an existing
+ * strategy buffer being reused, count this as a strategy write for the
+ * purposes of IO Operations statistics tracking.
+ *
+ * All dirty shared buffers upon first being added to the ring will be
+ * counted as shared buffer writes.
+ *
+ * When a strategy is not in use, the write can only be a only be a
+ * "regular" write of a dirty shared buffer.
+ */
+
+ iopath = from_ring ? IOPATH_STRATEGY : IOPATH_SHARED;
+
/* OK, do the I/O */
TRACE_POSTGRESQL_BUFFER_WRITE_DIRTY_START(forkNum, blockNum,
smgr->smgr_rlocator.locator.spcOid,
smgr->smgr_rlocator.locator.dbOid,
smgr->smgr_rlocator.locator.relNumber);
- FlushBuffer(buf, NULL);
+ FlushBuffer(buf, NULL, iopath);
LWLockRelease(BufferDescriptorGetContentLock(buf));
ScheduleBufferTagForWriteback(&BackendWritebackContext,
@@ -2563,7 +2591,7 @@ SyncOneBuffer(int buf_id, bool skip_recently_used, WritebackContext *wb_context)
PinBuffer_Locked(bufHdr);
LWLockAcquire(BufferDescriptorGetContentLock(bufHdr), LW_SHARED);
- FlushBuffer(bufHdr, NULL);
+ FlushBuffer(bufHdr, NULL, IOPATH_SHARED);
LWLockRelease(BufferDescriptorGetContentLock(bufHdr));
@@ -2810,9 +2838,12 @@ BufferGetTag(Buffer buffer, RelFileLocator *rlocator, ForkNumber *forknum,
*
* If the caller has an smgr reference for the buffer's relation, pass it
* as the second parameter. If not, pass NULL.
+ *
+ * IOPath will always be IOPATH_SHARED except when a buffer access strategy is
+ * used and the buffer being flushed is a buffer from the strategy ring.
*/
static void
-FlushBuffer(BufferDesc *buf, SMgrRelation reln)
+FlushBuffer(BufferDesc *buf, SMgrRelation reln, IOPath iopath)
{
XLogRecPtr recptr;
ErrorContextCallback errcallback;
@@ -2892,6 +2923,8 @@ FlushBuffer(BufferDesc *buf, SMgrRelation reln)
*/
bufToWrite = PageSetChecksumCopy((Page) bufBlock, buf->tag.blockNum);
+ pgstat_count_io_op(IOOP_WRITE, iopath);
+
if (track_io_timing)
INSTR_TIME_SET_CURRENT(io_start);
@@ -3539,6 +3572,8 @@ FlushRelationBuffers(Relation rel)
localpage,
false);
+ pgstat_count_io_op(IOOP_WRITE, IOPATH_LOCAL);
+
buf_state &= ~(BM_DIRTY | BM_JUST_DIRTIED);
pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
@@ -3574,7 +3609,7 @@ FlushRelationBuffers(Relation rel)
{
PinBuffer_Locked(bufHdr);
LWLockAcquire(BufferDescriptorGetContentLock(bufHdr), LW_SHARED);
- FlushBuffer(bufHdr, RelationGetSmgr(rel));
+ FlushBuffer(bufHdr, RelationGetSmgr(rel), IOPATH_SHARED);
LWLockRelease(BufferDescriptorGetContentLock(bufHdr));
UnpinBuffer(bufHdr, true);
}
@@ -3669,7 +3704,7 @@ FlushRelationsAllBuffers(SMgrRelation *smgrs, int nrels)
{
PinBuffer_Locked(bufHdr);
LWLockAcquire(BufferDescriptorGetContentLock(bufHdr), LW_SHARED);
- FlushBuffer(bufHdr, srelent->srel);
+ FlushBuffer(bufHdr, srelent->srel, IOPATH_SHARED);
LWLockRelease(BufferDescriptorGetContentLock(bufHdr));
UnpinBuffer(bufHdr, true);
}
@@ -3877,7 +3912,7 @@ FlushDatabaseBuffers(Oid dbid)
{
PinBuffer_Locked(bufHdr);
LWLockAcquire(BufferDescriptorGetContentLock(bufHdr), LW_SHARED);
- FlushBuffer(bufHdr, NULL);
+ FlushBuffer(bufHdr, NULL, IOPATH_SHARED);
LWLockRelease(BufferDescriptorGetContentLock(bufHdr));
UnpinBuffer(bufHdr, true);
}
@@ -3904,7 +3939,7 @@ FlushOneBuffer(Buffer buffer)
Assert(LWLockHeldByMe(BufferDescriptorGetContentLock(bufHdr)));
- FlushBuffer(bufHdr, NULL);
+ FlushBuffer(bufHdr, NULL, IOPATH_SHARED);
}
/*
diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c
index 990e081aae..62ec4518c8 100644
--- a/src/backend/storage/buffer/freelist.c
+++ b/src/backend/storage/buffer/freelist.c
@@ -15,6 +15,7 @@
*/
#include "postgres.h"
+#include "pgstat.h"
#include "port/atomics.h"
#include "storage/buf_internals.h"
#include "storage/bufmgr.h"
@@ -198,13 +199,15 @@ have_free_buffer(void)
* return the buffer with the buffer header spinlock still held.
*/
BufferDesc *
-StrategyGetBuffer(BufferAccessStrategy strategy, uint32 *buf_state)
+StrategyGetBuffer(BufferAccessStrategy strategy, uint32 *buf_state, bool *from_ring)
{
BufferDesc *buf;
int bgwprocno;
int trycounter;
uint32 local_buf_state; /* to avoid repeated (de-)referencing */
+ *from_ring = false;
+
/*
* If given a strategy object, see whether it can select a buffer. We
* assume strategy objects don't need buffer_strategy_lock.
@@ -212,8 +215,21 @@ StrategyGetBuffer(BufferAccessStrategy strategy, uint32 *buf_state)
if (strategy != NULL)
{
buf = GetBufferFromRing(strategy, buf_state);
- if (buf != NULL)
+ *from_ring = buf != NULL;
+ if (*from_ring)
+ {
+ /*
+ * When a strategy is in use, reused buffers from the strategy ring will
+ * be counted as allocations for the purposes of IO Operation statistics
+ * tracking.
+ *
+ * However, even when a strategy is in use, if a new buffer must be
+ * allocated from shared buffers and added to the ring, this is counted
+ * as a IOPATH_SHARED allocation.
+ */
+ pgstat_count_io_op(IOOP_ALLOC, IOPATH_STRATEGY);
return buf;
+ }
}
/*
@@ -247,6 +263,7 @@ StrategyGetBuffer(BufferAccessStrategy strategy, uint32 *buf_state)
* the rate of buffer consumption. Note that buffers recycled by a
* strategy object are intentionally not counted here.
*/
+ pgstat_count_io_op(IOOP_ALLOC, IOPATH_SHARED);
pg_atomic_fetch_add_u32(&StrategyControl->numBufferAllocs, 1);
/*
@@ -684,11 +701,13 @@ AddBufferToRing(BufferAccessStrategy strategy, BufferDesc *buf)
bool
StrategyRejectBuffer(BufferAccessStrategy strategy, BufferDesc *buf)
{
+
/* We only do this in bulkread mode */
if (strategy->btype != BAS_BULKREAD)
return false;
- /* Don't muck with behavior of normal buffer-replacement strategy */
+ /*
+ * Don't muck with behavior of normal buffer-replacement strategy */
if (!strategy->current_was_in_ring ||
strategy->buffers[strategy->current] != BufferDescriptorGetBuffer(buf))
return false;
diff --git a/src/backend/storage/buffer/localbuf.c b/src/backend/storage/buffer/localbuf.c
index 9c038851d7..2d231daef0 100644
--- a/src/backend/storage/buffer/localbuf.c
+++ b/src/backend/storage/buffer/localbuf.c
@@ -15,6 +15,7 @@
*/
#include "postgres.h"
+#include "pgstat.h"
#include "access/parallel.h"
#include "catalog/catalog.h"
#include "executor/instrument.h"
@@ -196,6 +197,8 @@ LocalBufferAlloc(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum,
LocalRefCount[b]++;
ResourceOwnerRememberBuffer(CurrentResourceOwner,
BufferDescriptorGetBuffer(bufHdr));
+
+ pgstat_count_io_op(IOOP_ALLOC, IOPATH_LOCAL);
break;
}
}
@@ -226,6 +229,8 @@ LocalBufferAlloc(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum,
localpage,
false);
+ pgstat_count_io_op(IOOP_WRITE, IOPATH_LOCAL);
+
/* Mark not-dirty now in case we error out below */
buf_state &= ~BM_DIRTY;
pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
diff --git a/src/backend/storage/sync/sync.c b/src/backend/storage/sync/sync.c
index 9d6a9e9109..65b69c4cbd 100644
--- a/src/backend/storage/sync/sync.c
+++ b/src/backend/storage/sync/sync.c
@@ -432,6 +432,8 @@ ProcessSyncRequests(void)
total_elapsed += elapsed;
processed++;
+ pgstat_count_io_op(IOOP_FSYNC, IOPATH_SHARED);
+
if (log_checkpoints)
elog(DEBUG1, "checkpoint sync: number=%d file=%s time=%.3f ms",
processed,
diff --git a/src/backend/utils/activity/Makefile b/src/backend/utils/activity/Makefile
index a2e8507fd6..0098785089 100644
--- a/src/backend/utils/activity/Makefile
+++ b/src/backend/utils/activity/Makefile
@@ -22,6 +22,7 @@ OBJS = \
pgstat_checkpointer.o \
pgstat_database.o \
pgstat_function.o \
+ pgstat_io_ops.o \
pgstat_relation.o \
pgstat_replslot.o \
pgstat_shmem.o \
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 88e5dd1b2b..3238d9ba85 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -359,6 +359,15 @@ static const PgStat_KindInfo pgstat_kind_infos[PGSTAT_NUM_KINDS] = {
.snapshot_cb = pgstat_checkpointer_snapshot_cb,
},
+ [PGSTAT_KIND_IOOPS] = {
+ .name = "io_ops",
+
+ .fixed_amount = true,
+
+ .reset_all_cb = pgstat_io_ops_reset_all_cb,
+ .snapshot_cb = pgstat_io_ops_snapshot_cb,
+ },
+
[PGSTAT_KIND_SLRU] = {
.name = "slru",
@@ -628,6 +637,9 @@ pgstat_report_stat(bool force)
/* flush database / relation / function / ... stats */
partial_flush |= pgstat_flush_pending_entries(nowait);
+ /* flush IO Operations stats */
+ partial_flush |= pgstat_flush_io_ops(nowait);
+
/* flush wal stats */
partial_flush |= pgstat_flush_wal(nowait);
@@ -1312,6 +1324,12 @@ pgstat_write_statsfile(void)
pgstat_build_snapshot_fixed(PGSTAT_KIND_CHECKPOINTER);
write_chunk_s(fpout, &pgStatLocal.snapshot.checkpointer);
+ /*
+ * Write IO Operations stats struct
+ */
+ pgstat_build_snapshot_fixed(PGSTAT_KIND_IOOPS);
+ write_chunk_s(fpout, &pgStatLocal.snapshot.io_ops);
+
/*
* Write SLRU stats struct
*/
@@ -1427,8 +1445,10 @@ pgstat_read_statsfile(void)
FILE *fpin;
int32 format_id;
bool found;
+ PgStat_BackendIOPathOps io_stats;
const char *statfile = PGSTAT_STAT_PERMANENT_FILENAME;
PgStat_ShmemControl *shmem = pgStatLocal.shmem;
+ PgStatShared_BackendIOPathOps *io_stats_shmem = &shmem->io_ops;
/* shouldn't be called from postmaster */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
@@ -1486,6 +1506,22 @@ pgstat_read_statsfile(void)
if (!read_chunk_s(fpin, &shmem->checkpointer.stats))
goto error;
+ /*
+ * Read IO Operations stats struct
+ */
+ if (!read_chunk_s(fpin, &io_stats))
+ goto error;
+
+ io_stats_shmem->stat_reset_timestamp = io_stats.stat_reset_timestamp;
+
+ for (int i = 0; i < BACKEND_NUM_TYPES; i++)
+ {
+ PgStat_IOPathOps *stats = &io_stats.stats[i];
+ PgStatShared_IOPathOps *stats_shmem = &io_stats_shmem->stats[i];
+
+ memcpy(stats_shmem->data, stats->data, sizeof(stats->data));
+ }
+
/*
* Read SLRU stats struct
*/
diff --git a/src/backend/utils/activity/pgstat_bgwriter.c b/src/backend/utils/activity/pgstat_bgwriter.c
index fbb1edc527..3d7f90a1b7 100644
--- a/src/backend/utils/activity/pgstat_bgwriter.c
+++ b/src/backend/utils/activity/pgstat_bgwriter.c
@@ -24,7 +24,7 @@ PgStat_BgWriterStats PendingBgWriterStats = {0};
/*
- * Report bgwriter statistics
+ * Report bgwriter and IO Operation statistics
*/
void
pgstat_report_bgwriter(void)
@@ -56,6 +56,11 @@ pgstat_report_bgwriter(void)
* Clear out the statistics buffer, so it can be re-used.
*/
MemSet(&PendingBgWriterStats, 0, sizeof(PendingBgWriterStats));
+
+ /*
+ * Report IO Operations statistics
+ */
+ pgstat_flush_io_ops(false);
}
/*
diff --git a/src/backend/utils/activity/pgstat_checkpointer.c b/src/backend/utils/activity/pgstat_checkpointer.c
index af8d513e7b..cfcf127210 100644
--- a/src/backend/utils/activity/pgstat_checkpointer.c
+++ b/src/backend/utils/activity/pgstat_checkpointer.c
@@ -24,7 +24,7 @@ PgStat_CheckpointerStats PendingCheckpointerStats = {0};
/*
- * Report checkpointer statistics
+ * Report checkpointer and IO Operation statistics
*/
void
pgstat_report_checkpointer(void)
@@ -62,6 +62,11 @@ pgstat_report_checkpointer(void)
* Clear out the statistics buffer, so it can be re-used.
*/
MemSet(&PendingCheckpointerStats, 0, sizeof(PendingCheckpointerStats));
+
+ /*
+ * Report IO Operation statistics
+ */
+ pgstat_flush_io_ops(false);
}
/*
diff --git a/src/backend/utils/activity/pgstat_io_ops.c b/src/backend/utils/activity/pgstat_io_ops.c
new file mode 100644
index 0000000000..ec2919cca6
--- /dev/null
+++ b/src/backend/utils/activity/pgstat_io_ops.c
@@ -0,0 +1,193 @@
+/* -------------------------------------------------------------------------
+ *
+ * pgstat_io_ops.c
+ * Implementation of IO operation statistics.
+ *
+ * This file contains the implementation of IO operation statistics. It is kept
+ * separate from pgstat.c to enforce the line between the statistics access /
+ * storage implementation and the details about individual types of
+ * statistics.
+ *
+ * Copyright (c) 2001-2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/backend/utils/activity/pgstat_io_ops.c
+ * -------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "utils/pgstat_internal.h"
+
+static PgStat_IOPathOps pending_IOOpStats;
+bool have_ioopstats = false;
+
+
+/*
+ * Flush out locally pending IO Operation statistics entries
+ *
+ * If nowait is true, this function returns false on lock failure. Otherwise
+ * this function always returns true.
+ *
+ * If nowait is true, this function returns true if the lock could not be
+ * acquired. Otherwise return false.
+ */
+bool
+pgstat_flush_io_ops(bool nowait)
+{
+ PgStatShared_IOPathOps *stats_shmem;
+
+ if (!have_ioopstats)
+ return false;
+
+
+ stats_shmem =
+ &pgStatLocal.shmem->io_ops.stats[MyBackendType];
+
+ if (!nowait)
+ LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE);
+ else if (!LWLockConditionalAcquire(&stats_shmem->lock, LW_EXCLUSIVE))
+ return true;
+
+
+ for (int i = 0; i < IOPATH_NUM_TYPES; i++)
+ {
+ PgStat_IOOpCounters *sharedent = &stats_shmem->data[i];
+ PgStat_IOOpCounters *pendingent = &pending_IOOpStats.data[i];
+
+#define IO_OP_ACC(fld) sharedent->fld += pendingent->fld
+ IO_OP_ACC(allocs);
+ IO_OP_ACC(extends);
+ IO_OP_ACC(fsyncs);
+ IO_OP_ACC(reads);
+ IO_OP_ACC(writes);
+#undef IO_OP_ACC
+ }
+
+ LWLockRelease(&stats_shmem->lock);
+
+ memset(&pending_IOOpStats, 0, sizeof(pending_IOOpStats));
+
+ have_ioopstats = false;
+
+ return false;
+}
+
+void
+pgstat_io_ops_snapshot_cb(void)
+{
+ PgStatShared_BackendIOPathOps *all_backend_stats_shmem = &pgStatLocal.shmem->io_ops;
+ PgStat_BackendIOPathOps *all_backend_stats_snap = &pgStatLocal.snapshot.io_ops;
+
+ for (int i = 0; i < BACKEND_NUM_TYPES; i++)
+ {
+ PgStatShared_IOPathOps *stats_shmem = &all_backend_stats_shmem->stats[i];
+ PgStat_IOPathOps *stats_snap = &all_backend_stats_snap->stats[i];
+
+ LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE);
+ /*
+ * Use the lock in the first BackendType's PgStat_IOPathOps to protect the
+ * reset timestamp as well.
+ */
+ if (i == 0)
+ all_backend_stats_snap->stat_reset_timestamp = all_backend_stats_shmem->stat_reset_timestamp;
+
+ memcpy(stats_snap->data, stats_shmem->data, sizeof(stats_shmem->data));
+ LWLockRelease(&stats_shmem->lock);
+ }
+
+}
+
+void
+pgstat_io_ops_reset_all_cb(TimestampTz ts)
+{
+ PgStatShared_BackendIOPathOps *all_backend_stats_shmem = &pgStatLocal.shmem->io_ops;
+
+ for (int i = 0; i < BACKEND_NUM_TYPES; i++)
+ {
+ PgStatShared_IOPathOps *stats_shmem = &all_backend_stats_shmem->stats[i];
+
+ LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE);
+
+ /*
+ * Use the lock in the first BackendType's PgStat_IOPathOps to protect the
+ * reset timestamp as well.
+ */
+ if (i == 0)
+ all_backend_stats_shmem->stat_reset_timestamp = ts;
+
+ memset(stats_shmem->data, 0, sizeof(stats_shmem->data));
+ LWLockRelease(&stats_shmem->lock);
+ }
+}
+
+void
+pgstat_count_io_op(IOOp io_op, IOPath io_path)
+{
+ PgStat_IOOpCounters *pending_counters = &pending_IOOpStats.data[io_path];
+
+ switch (io_op)
+ {
+ case IOOP_ALLOC:
+ pending_counters->allocs++;
+ break;
+ case IOOP_EXTEND:
+ pending_counters->extends++;
+ break;
+ case IOOP_FSYNC:
+ pending_counters->fsyncs++;
+ break;
+ case IOOP_READ:
+ pending_counters->reads++;
+ break;
+ case IOOP_WRITE:
+ pending_counters->writes++;
+ break;
+ }
+
+ have_ioopstats = true;
+}
+
+PgStat_BackendIOPathOps*
+pgstat_fetch_backend_io_path_ops(void)
+{
+ pgstat_snapshot_fixed(PGSTAT_KIND_IOOPS);
+
+ return &pgStatLocal.snapshot.io_ops;
+}
+
+const char *
+pgstat_io_path_desc(IOPath io_path)
+{
+ switch (io_path)
+ {
+ case IOPATH_LOCAL:
+ return "Local";
+ case IOPATH_SHARED:
+ return "Shared";
+ case IOPATH_STRATEGY:
+ return "Strategy";
+ }
+
+ elog(ERROR, "unrecognized IOPath value: %d", io_path);
+}
+
+const char *
+pgstat_io_op_desc(IOOp io_op)
+{
+ switch (io_op)
+ {
+ case IOOP_ALLOC:
+ return "Alloc";
+ case IOOP_EXTEND:
+ return "Extend";
+ case IOOP_FSYNC:
+ return "Fsync";
+ case IOOP_READ:
+ return "Read";
+ case IOOP_WRITE:
+ return "Write";
+ }
+
+ elog(ERROR, "unrecognized IOOp value: %d", io_op);
+}
diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c
index a846d9ffb6..a17b3336db 100644
--- a/src/backend/utils/activity/pgstat_relation.c
+++ b/src/backend/utils/activity/pgstat_relation.c
@@ -205,7 +205,7 @@ pgstat_drop_relation(Relation rel)
}
/*
- * Report that the table was just vacuumed.
+ * Report that the table was just vacuumed and flush IO Operation statistics.
*/
void
pgstat_report_vacuum(Oid tableoid, bool shared,
@@ -257,10 +257,18 @@ pgstat_report_vacuum(Oid tableoid, bool shared,
}
pgstat_unlock_entry(entry_ref);
+
+ /*
+ * Flush IO Operations statistics now. pgstat_report_stat() will flush IO
+ * Operation stats, however this will not be called after an entire
+ * autovacuum cycle is done -- which will likely vacuum many relations -- or
+ * until the VACUUM command has processed all tables and committed.
+ */
+ pgstat_flush_io_ops(false);
}
/*
- * Report that the table was just analyzed.
+ * Report that the table was just analyzed and flush IO Operation statistics.
*
* Caller must provide new live- and dead-tuples estimates, as well as a
* flag indicating whether to reset the changes_since_analyze counter.
@@ -340,6 +348,13 @@ pgstat_report_analyze(Relation rel,
}
pgstat_unlock_entry(entry_ref);
+
+ /*
+ * Flush IO Operations statistics explicitly for the same reason as in
+ * pgstat_report_vacuum(). We don't want to wait for an entire ANALYZE
+ * command to complete before updating stats.
+ */
+ pgstat_flush_io_ops(false);
}
/*
diff --git a/src/backend/utils/activity/pgstat_wal.c b/src/backend/utils/activity/pgstat_wal.c
index 5a878bd115..9cac407b42 100644
--- a/src/backend/utils/activity/pgstat_wal.c
+++ b/src/backend/utils/activity/pgstat_wal.c
@@ -34,7 +34,7 @@ static WalUsage prevWalUsage;
/*
* Calculate how much WAL usage counters have increased and update
- * shared statistics.
+ * shared WAL and IO Operation statistics.
*
* Must be called by processes that generate WAL, that do not call
* pgstat_report_stat(), like walwriter.
@@ -43,6 +43,8 @@ void
pgstat_report_wal(bool force)
{
pgstat_flush_wal(force);
+
+ pgstat_flush_io_ops(force);
}
/*
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 893690dad5..6259cc4f4c 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -2104,6 +2104,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS)
pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER);
pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER);
}
+ else if (strcmp(target, "io") == 0)
+ pgstat_reset_of_kind(PGSTAT_KIND_IOOPS);
else if (strcmp(target, "recovery_prefetch") == 0)
XLogPrefetchResetStats();
else if (strcmp(target, "wal") == 0)
@@ -2112,7 +2114,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized reset target: \"%s\"", target),
- errhint("Target must be \"archiver\", \"bgwriter\", \"recovery_prefetch\", or \"wal\".")));
+ errhint("Target must be \"archiver\", \"io\", \"bgwriter\", \"recovery_prefetch\", or \"wal\".")));
PG_RETURN_VOID();
}
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 5276bf25a1..e0b25c6815 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -331,6 +331,8 @@ typedef enum BackendType
B_WAL_WRITER,
} BackendType;
+#define BACKEND_NUM_TYPES B_WAL_WRITER + 1
+
extern PGDLLIMPORT BackendType MyBackendType;
extern const char *GetBackendTypeDesc(BackendType backendType);
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index ac28f813b4..d6ed6ec864 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -14,6 +14,7 @@
#include "datatype/timestamp.h"
#include "portability/instr_time.h"
#include "postmaster/pgarch.h" /* for MAX_XFN_CHARS */
+#include "storage/lwlock.h"
#include "utils/backend_progress.h" /* for backward compatibility */
#include "utils/backend_status.h" /* for backward compatibility */
#include "utils/relcache.h"
@@ -48,6 +49,7 @@ typedef enum PgStat_Kind
PGSTAT_KIND_ARCHIVER,
PGSTAT_KIND_BGWRITER,
PGSTAT_KIND_CHECKPOINTER,
+ PGSTAT_KIND_IOOPS,
PGSTAT_KIND_SLRU,
PGSTAT_KIND_WAL,
} PgStat_Kind;
@@ -276,6 +278,50 @@ typedef struct PgStat_CheckpointerStats
PgStat_Counter buf_fsync_backend;
} PgStat_CheckpointerStats;
+/*
+ * Types related to counting IO Operations for various IO Paths
+ */
+
+typedef enum IOOp
+{
+ IOOP_ALLOC,
+ IOOP_EXTEND,
+ IOOP_FSYNC,
+ IOOP_READ,
+ IOOP_WRITE,
+} IOOp;
+
+#define IOOP_NUM_TYPES (IOOP_WRITE + 1)
+
+typedef enum IOPath
+{
+ IOPATH_LOCAL,
+ IOPATH_SHARED,
+ IOPATH_STRATEGY,
+} IOPath;
+
+#define IOPATH_NUM_TYPES (IOPATH_STRATEGY + 1)
+
+typedef struct PgStat_IOOpCounters
+{
+ PgStat_Counter allocs;
+ PgStat_Counter extends;
+ PgStat_Counter fsyncs;
+ PgStat_Counter reads;
+ PgStat_Counter writes;
+} PgStat_IOOpCounters;
+
+typedef struct PgStat_IOPathOps
+{
+ PgStat_IOOpCounters data[IOPATH_NUM_TYPES];
+} PgStat_IOPathOps;
+
+typedef struct PgStat_BackendIOPathOps
+{
+ TimestampTz stat_reset_timestamp;
+ PgStat_IOPathOps stats[BACKEND_NUM_TYPES];
+} PgStat_BackendIOPathOps;
+
typedef struct PgStat_StatDBEntry
{
PgStat_Counter n_xact_commit;
@@ -453,6 +499,18 @@ extern void pgstat_report_checkpointer(void);
extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
+/*
+ * Functions in pgstat_io_ops.c
+ */
+
+extern void pgstat_count_io_op(IOOp io_op, IOPath io_path);
+extern bool pgstat_flush_io_ops(bool nowait);
+extern PgStat_BackendIOPathOps *pgstat_fetch_backend_io_path_ops(void);
+extern PgStat_Counter pgstat_fetch_cumulative_io_ops(IOPath io_path, IOOp io_op);
+extern const char *pgstat_io_op_desc(IOOp io_op);
+extern const char *pgstat_io_path_desc(IOPath io_path);
+
+
/*
* Functions in pgstat_database.c
*/
diff --git a/src/include/storage/buf_internals.h b/src/include/storage/buf_internals.h
index 69e45900ba..da18999f59 100644
--- a/src/include/storage/buf_internals.h
+++ b/src/include/storage/buf_internals.h
@@ -310,7 +310,7 @@ extern void ScheduleBufferTagForWriteback(WritebackContext *context, BufferTag *
/* freelist.c */
extern BufferDesc *StrategyGetBuffer(BufferAccessStrategy strategy,
- uint32 *buf_state);
+ uint32 *buf_state, bool *from_ring);
extern void StrategyFreeBuffer(BufferDesc *buf);
extern bool StrategyRejectBuffer(BufferAccessStrategy strategy,
BufferDesc *buf);
diff --git a/src/include/utils/backend_status.h b/src/include/utils/backend_status.h
index 7403bca25e..b401c7ade2 100644
--- a/src/include/utils/backend_status.h
+++ b/src/include/utils/backend_status.h
@@ -306,7 +306,6 @@ extern const char *pgstat_get_crashed_backend_activity(int pid, char *buffer,
int buflen);
extern uint64 pgstat_get_my_query_id(void);
-
/* ----------
* Support functions for the SQL-callable functions to
* generate the pgstat* views.
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9303d05427..3151c43dfe 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -329,6 +329,19 @@ typedef struct PgStatShared_Checkpointer
PgStat_CheckpointerStats reset_offset;
} PgStatShared_Checkpointer;
+typedef struct PgStatShared_IOPathOps
+{
+ LWLock lock;
+ PgStat_IOOpCounters data[IOPATH_NUM_TYPES];
+} PgStatShared_IOPathOps;
+
+typedef struct PgStatShared_BackendIOPathOps
+{
+ TimestampTz stat_reset_timestamp;
+ PgStatShared_IOPathOps stats[BACKEND_NUM_TYPES];
+} PgStatShared_BackendIOPathOps;
+
+
typedef struct PgStatShared_SLRU
{
/* lock protects ->stats */
@@ -419,6 +432,7 @@ typedef struct PgStat_ShmemControl
PgStatShared_Archiver archiver;
PgStatShared_BgWriter bgwriter;
PgStatShared_Checkpointer checkpointer;
+ PgStatShared_BackendIOPathOps io_ops;
PgStatShared_SLRU slru;
PgStatShared_Wal wal;
} PgStat_ShmemControl;
@@ -442,6 +456,8 @@ typedef struct PgStat_Snapshot
PgStat_CheckpointerStats checkpointer;
+ PgStat_BackendIOPathOps io_ops;
+
PgStat_SLRUStats slru[SLRU_NUM_ELEMENTS];
PgStat_WalStats wal;
@@ -549,6 +565,14 @@ extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, Time
extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+/*
+ * Functions in pgstat_io_ops.c
+ */
+
+extern void pgstat_io_ops_snapshot_cb(void);
+extern void pgstat_io_ops_reset_all_cb(TimestampTz ts);
+
+
/*
* Functions in pgstat_relation.c
*/
--
2.34.1
From 6d28dbdd174df4da115735c67f2dc3f5ff51555b Mon Sep 17 00:00:00 2001
From: Melanie Plageman <melanieplage...@gmail.com>
Date: Mon, 4 Jul 2022 15:44:17 -0400
Subject: [PATCH v26 4/4] Add system view tracking IO ops per backend type
Add pg_stat_io, a system view which tracks the number of IOOp (allocs,
extends, fsyncs, reads, and writes) done through each IOPath (shared
buffers, local buffers, strategy buffers) by each type of backend (e.g.
client backend, checkpointer).
Some IOPaths are not used by some BackendTypes and will not be in the
view. For example, checkpointer does not use a BufferAccessStrategy
(currently), so there will be no row for the "strategy" IOPath for
checkpointer.
Some IOOps are invalid in combination with certain IOPaths. Those cells
will be NULL in the view. For example, local buffers are not fsync'd so
cells for all BackendTypes for IOPATH_STRATEGY and IOOP_FSYNC will be
NULL.
View stats are fetched from statistics incremented when a backend
performs an IO Operation and maintained by the cumulative statistics
subsystem.
Each row of the view is stats for a particular BackendType for a
particular IOPath (e.g. shared buffer accesses by checkpointer) and
each column in the view is the total number of IO Operations done (e.g.
writes).
So a cell in the view would be, for example, the number of shared
buffers written by checkpointer since the last stats reset.
Note that some of the cells in the view are redundant with fields in
pg_stat_bgwriter (e.g. buffers_backend), however these have been kept in
pg_stat_bgwriter for backwards compatibility. Deriving the redundant
pg_stat_bgwriter stats from the IO operations stats structures was also
problematic due to the separate reset targets for 'bgwriter' and
'io'.
Suggested by Andres Freund
Author: Melanie Plageman <melanieplage...@gmail.com>
Reviewed-by: Justin Pryzby <pry...@telsasoft.com>, Kyotaro Horiguchi <horikyota....@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/20200124195226.lth52iydq2n2uilq%40alap3.anarazel.de
---
doc/src/sgml/monitoring.sgml | 117 ++++++++++++++++-
src/backend/catalog/system_views.sql | 12 ++
src/backend/utils/adt/pgstatfuncs.c | 110 ++++++++++++++++
src/include/catalog/pg_proc.dat | 9 ++
src/test/regress/expected/rules.out | 9 ++
src/test/regress/expected/stats.out | 190 +++++++++++++++++++++++++++
src/test/regress/sql/stats.sql | 91 +++++++++++++
7 files changed, 537 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index f2066e5f0f..105e86d678 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -448,6 +448,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser
</entry>
</row>
+ <row>
+ <entry><structname>pg_stat_io</structname><indexterm><primary>pg_stat_io</primary></indexterm></entry>
+ <entry>A row for each IO path for each backend type showing
+ statistics about backend IO operations. See
+ <link linkend="monitoring-pg-stat-io-view">
+ <structname>pg_stat_io</structname></link> for details.
+ </entry>
+ </row>
+
<row>
<entry><structname>pg_stat_wal</structname><indexterm><primary>pg_stat_wal</primary></indexterm></entry>
<entry>One row only, showing statistics about WAL activity. See
@@ -3600,7 +3609,111 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
<structfield>stats_reset</structfield> <type>timestamp with time zone</type>
</para>
<para>
- Time at which these statistics were last reset
+ Time at which these statistics were last reset.
+ </para></entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ </sect2>
+
+ <sect2 id="monitoring-pg-stat-io-view">
+ <title><structname>pg_stat_io</structname></title>
+
+ <indexterm>
+ <primary>pg_stat_io</primary>
+ </indexterm>
+
+ <para>
+ The <structname>pg_stat_io</structname> view has a row for each backend
+ type for each possible IO path containing global data for the cluster for
+ that backend and IO path.
+ </para>
+
+ <table id="pg-stat-io-view" xreflabel="pg_stat_io">
+ <title><structname>pg_stat_io</structname> View</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>backend_type</structfield> <type>text</type>
+ </para>
+ <para>
+ Type of backend (e.g. background worker, autovacuum worker).
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>io_path</structfield> <type>text</type>
+ </para>
+ <para>
+ IO path taken (e.g. shared buffers, direct).
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>alloc</structfield> <type>bigint</type>
+ </para>
+ <para>
+ Number of buffers allocated.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>extend</structfield> <type>bigint</type>
+ </para>
+ <para>
+ Number of blocks extended.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>fsync</structfield> <type>bigint</type>
+ </para>
+ <para>
+ Number of blocks fsynced.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>read</structfield> <type>bigint</type>
+ </para>
+ <para>
+ Number of blocks read.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>write</structfield> <type>bigint</type>
+ </para>
+ <para>
+ Number of blocks written.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>stats_reset</structfield> <type>timestamp with time zone</type>
+ </para>
+ <para>
+ Time at which these statistics were last reset.
</para></entry>
</row>
</tbody>
@@ -5360,6 +5473,8 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
the <structname>pg_stat_bgwriter</structname>
view, <literal>archiver</literal> to reset all the counters shown in
the <structname>pg_stat_archiver</structname> view,
+ <literal>io</literal> to reset all the counters shown in the
+ <structname>pg_stat_io</structname> view,
<literal>wal</literal> to reset all the counters shown in the
<structname>pg_stat_wal</structname> view or
<literal>recovery_prefetch</literal> to reset all the counters shown
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index fedaed533b..1fe3b07daa 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1115,6 +1115,18 @@ CREATE VIEW pg_stat_bgwriter AS
pg_stat_get_buf_alloc() AS buffers_alloc,
pg_stat_get_bgwriter_stat_reset_time() AS stats_reset;
+CREATE VIEW pg_stat_io AS
+SELECT
+ b.backend_type,
+ b.io_path,
+ b.alloc,
+ b.extend,
+ b.fsync,
+ b.read,
+ b.write,
+ b.stats_reset
+FROM pg_stat_get_io() b;
+
CREATE VIEW pg_stat_wal AS
SELECT
w.wal_records,
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 6259cc4f4c..1c905d5413 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1739,6 +1739,116 @@ pg_stat_get_buf_alloc(PG_FUNCTION_ARGS)
PG_RETURN_INT64(pgstat_fetch_stat_bgwriter()->buf_alloc);
}
+/*
+* When adding a new column to the pg_stat_io view, add a new enum
+* value here above IO_NUM_COLUMNS.
+*/
+enum
+{
+ IO_COLUMN_BACKEND_TYPE,
+ IO_COLUMN_IO_PATH,
+ IO_COLUMN_ALLOCS,
+ IO_COLUMN_EXTENDS,
+ IO_COLUMN_FSYNCS,
+ IO_COLUMN_READS,
+ IO_COLUMN_WRITES,
+ IO_COLUMN_RESET_TIME,
+ IO_NUM_COLUMNS,
+};
+
+Datum
+pg_stat_get_io(PG_FUNCTION_ARGS)
+{
+ PgStat_BackendIOPathOps *io_stats;
+ ReturnSetInfo *rsinfo;
+ Datum reset_time;
+
+ SetSingleFuncCall(fcinfo, 0);
+ rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+
+ io_stats = pgstat_fetch_backend_io_path_ops();
+
+ /*
+ * Currently it is not permitted to reset IO operation stats for individual
+ * IO Paths or individual BackendTypes. All IO Operation statistics are
+ * reset together. As such, it is easiest to reuse the first reset timestamp
+ * available.
+ */
+ reset_time = TimestampTzGetDatum(io_stats->stat_reset_timestamp);
+
+ for (int i = 0; i < BACKEND_NUM_TYPES; i++)
+ {
+ bool uses_local;
+ bool uses_strategy;
+ Datum backend_type_desc = CStringGetTextDatum(GetBackendTypeDesc(i));
+ PgStat_IOPathOps *io_path_ops = &io_stats->stats[i];
+
+
+ /*
+ * IO Operation statistics are not collected for all BackendTypes.
+ * For those BackendTypes without IO Operation stats, skip representing them
+ * in the view altogether.
+ *
+ * The following BackendTypes do not participate in the cumulative stats
+ * subsystem or do not do IO operations worth reporting statistics on:
+ * - Startup process because it does not have relation OIDs
+ * - Syslogger because it is not connected to shared memory
+ * - Archiver because most relevant archiving IO is delegated to a
+ * specialized command or module
+ * - WAL Receiver and WAL Writer IO is not tracked in pg_stat_io for now
+ */
+ if (i == B_INVALID || i == B_ARCHIVER || i == B_LOGGER || i == B_STARTUP ||
+ i == B_WAL_RECEIVER || i == B_WAL_WRITER)
+ continue;
+
+ /*
+ * Not all BackendTypes will use a BufferAccessStrategy. Omit those rows
+ * from the view.
+ */
+ uses_strategy = i == B_AUTOVAC_WORKER || i == B_BACKEND || i ==
+ B_STANDALONE_BACKEND || i == B_BG_WORKER;
+
+ uses_local = i == B_BACKEND || i == B_WAL_SENDER;
+
+ for (int j = 0; j < IOPATH_NUM_TYPES; j++)
+ {
+ PgStat_IOOpCounters *counters = &io_path_ops->data[j];
+ Datum values[IO_NUM_COLUMNS];
+ bool nulls[IO_NUM_COLUMNS];
+
+ if (j == IOPATH_STRATEGY && !uses_strategy)
+ continue;
+
+ if (j == IOPATH_LOCAL && !uses_local)
+ continue;
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, 0, sizeof(nulls));
+
+ values[IO_COLUMN_BACKEND_TYPE] = backend_type_desc;
+ values[IO_COLUMN_IO_PATH] = CStringGetTextDatum(pgstat_io_path_desc(j));
+ values[IO_COLUMN_RESET_TIME] = TimestampTzGetDatum(reset_time);
+ values[IO_COLUMN_ALLOCS] = Int64GetDatum(counters->allocs);
+ values[IO_COLUMN_EXTENDS] = Int64GetDatum(counters->extends);
+ values[IO_COLUMN_FSYNCS] = Int64GetDatum(counters->fsyncs);
+ values[IO_COLUMN_READS] = Int64GetDatum(counters->reads);
+ values[IO_COLUMN_WRITES] = Int64GetDatum(counters->writes);
+
+ /*
+ * Temporary tables using local buffers are not logged and thus do not
+ * require fsync'ing. Set this cell to NULL to differentiate between an
+ * invalid combination and 0 observed IO Operations.
+ */
+ if (j == IOPATH_LOCAL)
+ nulls[IO_COLUMN_FSYNCS] = true;
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
+ }
+ }
+
+ return (Datum) 0;
+}
+
/*
* Returns statistics of WAL activity
*/
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 2e41f4d9e8..bec3c93991 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5646,6 +5646,15 @@
proname => 'pg_stat_get_buf_alloc', provolatile => 's', proparallel => 'r',
prorettype => 'int8', proargtypes => '', prosrc => 'pg_stat_get_buf_alloc' },
+{ oid => '8459', descr => 'statistics: counts of all IO operations done through all IO paths by each type of backend.',
+ proname => 'pg_stat_get_io', provolatile => 's', proisstrict => 'f',
+ prorows => '52', proretset => 't',
+ proparallel => 'r', prorettype => 'record', proargtypes => '',
+ proallargtypes => '{text,text,int8,int8,int8,int8,int8,timestamptz}',
+ proargmodes => '{o,o,o,o,o,o,o,o}',
+ proargnames => '{backend_type,io_path,alloc,extend,fsync,read,write,stats_reset}',
+ prosrc => 'pg_stat_get_io' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 7ec3d2688f..2b269e005e 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1873,6 +1873,15 @@ pg_stat_gssapi| SELECT s.pid,
s.gss_enc AS encrypted
FROM pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid, query_id)
WHERE (s.client_port IS NOT NULL);
+pg_stat_io| SELECT b.backend_type,
+ b.io_path,
+ b.alloc,
+ b.extend,
+ b.fsync,
+ b.read,
+ b.write,
+ b.stats_reset
+ FROM pg_stat_get_io() b(backend_type, io_path, alloc, extend, fsync, read, write, stats_reset);
pg_stat_progress_analyze| SELECT s.pid,
s.datid,
d.datname,
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 5b0ebf090f..7cdcadacd6 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -554,4 +554,194 @@ SELECT pg_stat_get_live_tuples(:drop_stats_test_subxact_oid);
DROP TABLE trunc_stats_test, trunc_stats_test1, trunc_stats_test2, trunc_stats_test3, trunc_stats_test4;
DROP TABLE prevstats;
+-- Test that allocs, extends, reads, and writes to Shared Buffers and fsyncs
+-- done to ensure durability of Shared Buffers are tracked in pg_stat_io.
+SELECT sum(alloc) AS io_sum_shared_allocs_before FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(extend) AS io_sum_shared_extends_before FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(fsync) AS io_sum_shared_fsyncs_before FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(read) AS io_sum_shared_reads_before FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(write) AS io_sum_shared_writes_before FROM pg_stat_io WHERE io_path = 'Shared' \gset
+-- Create a regular table and insert some data to generate IOPATH_SHARED allocs and extends.
+CREATE TABLE test_io_shared(a int);
+INSERT INTO test_io_shared SELECT i FROM generate_series(1,100)i;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+-- After a checkpoint, there should be some additional IOPATH_SHARED writes and fsyncs.
+CHECKPOINT;
+SELECT sum(alloc) AS io_sum_shared_allocs_after FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(extend) AS io_sum_shared_extends_after FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(write) AS io_sum_shared_writes_after FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(fsync) AS io_sum_shared_fsyncs_after FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT :io_sum_shared_allocs_after > :io_sum_shared_allocs_before;
+ ?column?
+----------
+ t
+(1 row)
+
+SELECT :io_sum_shared_extends_after > :io_sum_shared_extends_before;
+ ?column?
+----------
+ t
+(1 row)
+
+SELECT current_setting('fsync') = 'off' OR :io_sum_shared_fsyncs_after > :io_sum_shared_fsyncs_before;
+ ?column?
+----------
+ t
+(1 row)
+
+SELECT :io_sum_shared_writes_after > :io_sum_shared_writes_before;
+ ?column?
+----------
+ t
+(1 row)
+
+-- Change the tablespace so that the table is rewritten directly, then SELECT
+-- from it to cause it to be read back into Shared Buffers.
+SET allow_in_place_tablespaces = true;
+CREATE TABLESPACE test_io_shared_stats_tblspc LOCATION '';
+ALTER TABLE test_io_shared SET TABLESPACE test_io_shared_stats_tblspc;
+SELECT COUNT(*) FROM test_io_shared;
+ count
+-------
+ 100
+(1 row)
+
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT sum(read) AS io_sum_shared_reads_after FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT :io_sum_shared_reads_after > :io_sum_shared_reads_before;
+ ?column?
+----------
+ t
+(1 row)
+
+DROP TABLE test_io_shared;
+DROP TABLESPACE test_io_shared_stats_tblspc;
+-- Test that allocs, extends, reads, and writes of temporary tables are tracked
+-- in pg_stat_io.
+CREATE TEMPORARY TABLE test_io_local(a int, b TEXT);
+SELECT sum(alloc) AS io_sum_local_allocs_before FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(extend) AS io_sum_local_extends_before FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(read) AS io_sum_local_reads_before FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(write) AS io_sum_local_writes_before FROM pg_stat_io WHERE io_path = 'Local' \gset
+-- Insert enough values that we need to reuse and write out dirty local
+-- buffers.
+INSERT INTO test_io_local SELECT generate_series(1, 80000) as id,
+'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa';
+-- Read in evicted buffers.
+SELECT COUNT(*) FROM test_io_local;
+ count
+-------
+ 80000
+(1 row)
+
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT sum(alloc) AS io_sum_local_allocs_after FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(extend) AS io_sum_local_extends_after FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(read) AS io_sum_local_reads_after FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(write) AS io_sum_local_writes_after FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT :io_sum_local_allocs_after > :io_sum_local_allocs_before;
+ ?column?
+----------
+ t
+(1 row)
+
+SELECT :io_sum_local_extends_after > :io_sum_local_extends_before;
+ ?column?
+----------
+ t
+(1 row)
+
+SELECT :io_sum_local_reads_after > :io_sum_local_reads_before;
+ ?column?
+----------
+ t
+(1 row)
+
+SELECT :io_sum_local_writes_after > :io_sum_local_writes_before;
+ ?column?
+----------
+ t
+(1 row)
+
+-- Test that, when using a Strategy, reusing buffers from the Strategy ring
+-- count as "Strategy" allocs in pg_stat_io. Also test that Strategy reads are
+-- counted as such.
+SELECT sum(alloc) AS io_sum_strategy_allocs_before FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+SELECT sum(read) AS io_sum_strategy_reads_before FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+CREATE TABLE test_io_strategy(a INT, b INT);
+ALTER TABLE test_io_strategy SET (autovacuum_enabled = 'false');
+INSERT INTO test_io_strategy SELECT i, i from generate_series(1, 8000)i;
+-- Ensure that the next VACUUM will need to perform IO by rewriting the table
+-- first with VACUUM (FULL).
+VACUUM (FULL) test_io_strategy;
+VACUUM (PARALLEL 0) test_io_strategy;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT sum(alloc) AS io_sum_strategy_allocs_after FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+SELECT sum(read) AS io_sum_strategy_reads_after FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+SELECT :io_sum_strategy_allocs_after > :io_sum_strategy_allocs_before;
+ ?column?
+----------
+ t
+(1 row)
+
+SELECT :io_sum_strategy_reads_after > :io_sum_strategy_reads_before;
+ ?column?
+----------
+ t
+(1 row)
+
+DROP TABLE test_io_strategy;
+-- Test that, when using a Strategy, if creating a relation, Strategy extends
+-- are counted in pg_stat_io.
+-- A CTAS uses a Bulkwrite strategy.
+SELECT sum(extend) AS io_sum_strategy_extends_before FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+CREATE TABLE test_io_strategy_extend AS SELECT i FROM generate_series(1,100)i;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT sum(extend) AS io_sum_strategy_extends_after FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+SELECT :io_sum_strategy_extends_after > :io_sum_strategy_extends_before;
+ ?column?
+----------
+ t
+(1 row)
+
+DROP TABLE test_io_strategy_extend;
+SELECT sum(alloc) + sum(extend) + sum(fsync) + sum(read) + sum(write) AS io_stats_pre_reset FROM pg_stat_io \gset
+SELECT pg_stat_reset_shared('io');
+ pg_stat_reset_shared
+----------------------
+
+(1 row)
+
+SELECT sum(alloc) + sum(extend) + sum(fsync) + sum(read) + sum(write) AS io_stats_post_reset FROM pg_stat_io \gset
+SELECT :io_stats_post_reset < :io_stats_pre_reset;
+ ?column?
+----------
+ t
+(1 row)
+
-- End of Stats Test
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 3f3cf8fb56..4d8932feba 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -285,4 +285,95 @@ SELECT pg_stat_get_live_tuples(:drop_stats_test_subxact_oid);
DROP TABLE trunc_stats_test, trunc_stats_test1, trunc_stats_test2, trunc_stats_test3, trunc_stats_test4;
DROP TABLE prevstats;
+
+-- Test that allocs, extends, reads, and writes to Shared Buffers and fsyncs
+-- done to ensure durability of Shared Buffers are tracked in pg_stat_io.
+SELECT sum(alloc) AS io_sum_shared_allocs_before FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(extend) AS io_sum_shared_extends_before FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(fsync) AS io_sum_shared_fsyncs_before FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(read) AS io_sum_shared_reads_before FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(write) AS io_sum_shared_writes_before FROM pg_stat_io WHERE io_path = 'Shared' \gset
+-- Create a regular table and insert some data to generate IOPATH_SHARED allocs and extends.
+CREATE TABLE test_io_shared(a int);
+INSERT INTO test_io_shared SELECT i FROM generate_series(1,100)i;
+SELECT pg_stat_force_next_flush();
+-- After a checkpoint, there should be some additional IOPATH_SHARED writes and fsyncs.
+CHECKPOINT;
+SELECT sum(alloc) AS io_sum_shared_allocs_after FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(extend) AS io_sum_shared_extends_after FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(write) AS io_sum_shared_writes_after FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT sum(fsync) AS io_sum_shared_fsyncs_after FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT :io_sum_shared_allocs_after > :io_sum_shared_allocs_before;
+SELECT :io_sum_shared_extends_after > :io_sum_shared_extends_before;
+SELECT current_setting('fsync') = 'off' OR :io_sum_shared_fsyncs_after > :io_sum_shared_fsyncs_before;
+SELECT :io_sum_shared_writes_after > :io_sum_shared_writes_before;
+-- Change the tablespace so that the table is rewritten directly, then SELECT
+-- from it to cause it to be read back into Shared Buffers.
+SET allow_in_place_tablespaces = true;
+CREATE TABLESPACE test_io_shared_stats_tblspc LOCATION '';
+ALTER TABLE test_io_shared SET TABLESPACE test_io_shared_stats_tblspc;
+SELECT COUNT(*) FROM test_io_shared;
+SELECT pg_stat_force_next_flush();
+SELECT sum(read) AS io_sum_shared_reads_after FROM pg_stat_io WHERE io_path = 'Shared' \gset
+SELECT :io_sum_shared_reads_after > :io_sum_shared_reads_before;
+DROP TABLE test_io_shared;
+DROP TABLESPACE test_io_shared_stats_tblspc;
+
+-- Test that allocs, extends, reads, and writes of temporary tables are tracked
+-- in pg_stat_io.
+CREATE TEMPORARY TABLE test_io_local(a int, b TEXT);
+SELECT sum(alloc) AS io_sum_local_allocs_before FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(extend) AS io_sum_local_extends_before FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(read) AS io_sum_local_reads_before FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(write) AS io_sum_local_writes_before FROM pg_stat_io WHERE io_path = 'Local' \gset
+-- Insert enough values that we need to reuse and write out dirty local
+-- buffers.
+INSERT INTO test_io_local SELECT generate_series(1, 80000) as id,
+'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa';
+-- Read in evicted buffers.
+SELECT COUNT(*) FROM test_io_local;
+SELECT pg_stat_force_next_flush();
+SELECT sum(alloc) AS io_sum_local_allocs_after FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(extend) AS io_sum_local_extends_after FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(read) AS io_sum_local_reads_after FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT sum(write) AS io_sum_local_writes_after FROM pg_stat_io WHERE io_path = 'Local' \gset
+SELECT :io_sum_local_allocs_after > :io_sum_local_allocs_before;
+SELECT :io_sum_local_extends_after > :io_sum_local_extends_before;
+SELECT :io_sum_local_reads_after > :io_sum_local_reads_before;
+SELECT :io_sum_local_writes_after > :io_sum_local_writes_before;
+
+-- Test that, when using a Strategy, reusing buffers from the Strategy ring
+-- count as "Strategy" allocs in pg_stat_io. Also test that Strategy reads are
+-- counted as such.
+SELECT sum(alloc) AS io_sum_strategy_allocs_before FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+SELECT sum(read) AS io_sum_strategy_reads_before FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+CREATE TABLE test_io_strategy(a INT, b INT);
+ALTER TABLE test_io_strategy SET (autovacuum_enabled = 'false');
+INSERT INTO test_io_strategy SELECT i, i from generate_series(1, 8000)i;
+-- Ensure that the next VACUUM will need to perform IO by rewriting the table
+-- first with VACUUM (FULL).
+VACUUM (FULL) test_io_strategy;
+VACUUM (PARALLEL 0) test_io_strategy;
+SELECT pg_stat_force_next_flush();
+SELECT sum(alloc) AS io_sum_strategy_allocs_after FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+SELECT sum(read) AS io_sum_strategy_reads_after FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+SELECT :io_sum_strategy_allocs_after > :io_sum_strategy_allocs_before;
+SELECT :io_sum_strategy_reads_after > :io_sum_strategy_reads_before;
+DROP TABLE test_io_strategy;
+
+-- Test that, when using a Strategy, if creating a relation, Strategy extends
+-- are counted in pg_stat_io.
+-- A CTAS uses a Bulkwrite strategy.
+SELECT sum(extend) AS io_sum_strategy_extends_before FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+CREATE TABLE test_io_strategy_extend AS SELECT i FROM generate_series(1,100)i;
+SELECT pg_stat_force_next_flush();
+SELECT sum(extend) AS io_sum_strategy_extends_after FROM pg_stat_io WHERE io_path = 'Strategy' \gset
+SELECT :io_sum_strategy_extends_after > :io_sum_strategy_extends_before;
+DROP TABLE test_io_strategy_extend;
+
+SELECT sum(alloc) + sum(extend) + sum(fsync) + sum(read) + sum(write) AS io_stats_pre_reset FROM pg_stat_io \gset
+SELECT pg_stat_reset_shared('io');
+SELECT sum(alloc) + sum(extend) + sum(fsync) + sum(read) + sum(write) AS io_stats_post_reset FROM pg_stat_io \gset
+SELECT :io_stats_post_reset < :io_stats_pre_reset;
+
-- End of Stats Test
--
2.34.1
From 2c869d7c48ddcedf52d61b2c18173c19e588c48b Mon Sep 17 00:00:00 2001
From: Melanie Plageman <melanieplage...@gmail.com>
Date: Tue, 12 Jul 2022 19:53:23 -0400
Subject: [PATCH v26 2/4] Remove unneeded call to pgstat_report_wal()
pgstat_report_stat() will be called before shutdown so an explicit call
to pgstat_report_wal() is wasted.
---
src/backend/postmaster/walwriter.c | 11 -----------
1 file changed, 11 deletions(-)
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index e926f8c27c..beb46dcb55 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -293,18 +293,7 @@ HandleWalWriterInterrupts(void)
}
if (ShutdownRequestPending)
- {
- /*
- * Force reporting remaining WAL statistics at process exit.
- *
- * Since pgstat_report_wal is invoked with 'force' is false in main
- * loop to avoid overloading the cumulative stats system, there may
- * exist unreported stats counters for the WAL writer.
- */
- pgstat_report_wal(true);
-
proc_exit(0);
- }
/* Perform logging of memory contexts of this process */
if (LogMemoryContextPending)
--
2.34.1
From 49251edea9c1d02420ae358db5d78cf0ef36504b Mon Sep 17 00:00:00 2001
From: Melanie Plageman <melanieplage...@gmail.com>
Date: Tue, 28 Jun 2022 11:33:04 -0400
Subject: [PATCH v26 1/4] Add BackendType for standalone backends
All backends should have a BackendType to enable statistics reporting
per BackendType.
Add a new BackendType for standalone backends, B_STANDALONE_BACKEND (and
alphabetize the BackendTypes). Both the bootstrap backend and single
user mode backends will have BackendType B_STANDALONE_BACKEND.
Author: Melanie Plageman <melanieplage...@gmail.com>
Discussion: https://www.postgresql.org/message-id/CAAKRu_aaq33UnG4TXq3S-OSXGWj1QGf0sU%2BECH4tNwGFNERkZA%40mail.gmail.com
---
src/backend/utils/init/miscinit.c | 17 +++++++++++------
src/include/miscadmin.h | 5 +++--
2 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c
index eb43b2c5e5..07e6db1a1c 100644
--- a/src/backend/utils/init/miscinit.c
+++ b/src/backend/utils/init/miscinit.c
@@ -176,6 +176,8 @@ InitStandaloneProcess(const char *argv0)
{
Assert(!IsPostmasterEnvironment);
+ MyBackendType = B_STANDALONE_BACKEND;
+
/*
* Start our win32 signal implementation
*/
@@ -255,6 +257,9 @@ GetBackendTypeDesc(BackendType backendType)
case B_INVALID:
backendDesc = "not initialized";
break;
+ case B_ARCHIVER:
+ backendDesc = "archiver";
+ break;
case B_AUTOVAC_LAUNCHER:
backendDesc = "autovacuum launcher";
break;
@@ -273,6 +278,12 @@ GetBackendTypeDesc(BackendType backendType)
case B_CHECKPOINTER:
backendDesc = "checkpointer";
break;
+ case B_LOGGER:
+ backendDesc = "logger";
+ break;
+ case B_STANDALONE_BACKEND:
+ backendDesc = "standalone backend";
+ break;
case B_STARTUP:
backendDesc = "startup";
break;
@@ -285,12 +296,6 @@ GetBackendTypeDesc(BackendType backendType)
case B_WAL_WRITER:
backendDesc = "walwriter";
break;
- case B_ARCHIVER:
- backendDesc = "archiver";
- break;
- case B_LOGGER:
- backendDesc = "logger";
- break;
}
return backendDesc;
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index ea9a56d395..5276bf25a1 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -316,18 +316,19 @@ extern void SwitchBackToLocalLatch(void);
typedef enum BackendType
{
B_INVALID = 0,
+ B_ARCHIVER,
B_AUTOVAC_LAUNCHER,
B_AUTOVAC_WORKER,
B_BACKEND,
B_BG_WORKER,
B_BG_WRITER,
B_CHECKPOINTER,
+ B_LOGGER,
+ B_STANDALONE_BACKEND,
B_STARTUP,
B_WAL_RECEIVER,
B_WAL_SENDER,
B_WAL_WRITER,
- B_ARCHIVER,
- B_LOGGER,
} BackendType;
extern PGDLLIMPORT BackendType MyBackendType;
--
2.34.1
