On Tue, Apr 6, 2021 at 12:19 PM Amit Kapila <amit.kapil...@gmail.com> wrote:
>
> On Mon, Apr 5, 2021 at 8:51 PM vignesh C <vignes...@gmail.com> wrote:
> >
>
> Few comments on the latest patches:
> Comments on 0001
> --------------------------------
> 1.
> @@ -659,6 +661,8 @@ ReorderBufferTXNByXid(ReorderBuffer *rb,
> TransactionId xid, bool create,
> dlist_push_tail(&rb->toplevel_by_lsn, &txn->node);
> AssertTXNLsnOrder(rb);
> }
> +
> + rb->totalTxns++;
> }
> else
> txn = NULL; /* not found and not asked to create */
> @@ -3078,6 +3082,7 @@ ReorderBufferChangeMemoryUpdate(ReorderBuffer *rb,
> {
> txn->size += sz;
> rb->size += sz;
> + rb->totalBytes += sz;
>
> I think this will include the txns that are aborted and for which we
> don't send anything. It might be better to update these stats in
> ReorderBufferProcessTXN or ReorderBufferReplay where we are sure we
> have sent the data. We can probably use size/total_size in txn. We
> need to be careful to not double include the totaltxn or totalBytes
> for streaming xacts as we might process the same txn multiple times.
Modified it to update total_byte for spilled transactions and streamed
transactions where spill_bytes and stream_bytes are updated. For
non-stream/spilled transactions, total_bytes is updated in
ReorderBufferProcessTXN.
> 2.
> + Amount of decoded transactions data sent to the decoding output
> plugin
> + while decoding the changes from WAL for this slot. This and
> total_txns
> + for this slot can be used to gauge the total amount of data during
> + logical decoding.
>
> I think we can slightly modify the second line here: "This can be used
> to gauge the total amount of data sent during logical decoding.". Why
> we need to include total_txns along with it.
Modified it.
> 0002
> ----------
> 3.
> + -- we don't want to wait forever; loop will exit after 30 seconds
> + FOR i IN 1 .. 5 LOOP
> +
> ...
> ...
> +
> + -- wait a little
> + perform pg_sleep_for('100 milliseconds');
>
> I think this loop needs to be executed 300 times instead of 5 times,
> if the above comments and code needs to do what is expected here?
>
Modified it.
> 4.
> +# Test to drop one of the subscribers and verify replication statistics data
> is
> +# fine after publisher is restarted.
> +$node->safe_psql('postgres', "SELECT
> pg_drop_replication_slot('regression_slot4')");
> +
> +$node->stop;
> +$node->start;
> +
> +# Verify statistics data present in pg_stat_replication_slots are sane after
> +# publisher is restarted
> +$result = $node->safe_psql('postgres',
> + "SELECT slot_name, total_txns > 0 AS total_txn, total_bytes > 0 AS
> total_bytes
> + FROM pg_stat_replication_slots ORDER BY slot_name"
>
> Various comments in the 0002 refer to publisher/subscriber which is
> not what we are using here.
Removed references to publisher/subscriber.
> 5.
> +# Create table.
> +$node->safe_psql('postgres',
> + "CREATE TABLE test_repl_stat(col1 int)");
> +$node->safe_psql('postgres',
> + "SELECT data FROM
> pg_logical_slot_get_changes('regression_slot1', NULL, NULL,
> 'include-xids', '0', 'skip-empty-xacts', '1')");
> +$node->safe_psql('postgres',
> + "SELECT data FROM
> pg_logical_slot_get_changes('regression_slot2', NULL, NULL,
> 'include-xids', '0', 'skip-empty-xacts', '1')");
> +$node->safe_psql('postgres',
> + "SELECT data FROM
> pg_logical_slot_get_changes('regression_slot3', NULL, NULL,
> 'include-xids', '0', 'skip-empty-xacts', '1')");
> +$node->safe_psql('postgres',
> + "SELECT data FROM
> pg_logical_slot_get_changes('regression_slot4', NULL, NULL,
> 'include-xids', '0', 'skip-empty-xacts', '1')");
>
> I think we can save the above calls to pg_logical_slot_get_changes if
> we create table before creating the slots in this test.
>
Modified it.
> 0003
> ---------
> 6. In the tests/code, publisher is used at multiple places. I think
> that is not required because this can happen via plugin as well.
Removed references to publisher.
> 7.
> + if (max_replication_slots == nReplSlotStats)
> + {
> + ereport(pgStatRunningInCollector ? LOG : WARNING,
> + (errmsg("skipping \"%s\" replication slot statistics as
> pg_stat_replication_slots does not have enough slots",
> + NameStr(replSlotStats[nReplSlotStats].slotname))));
> + memset(&replSlotStats[nReplSlotStats], 0, sizeof(PgStat_ReplSlotStats));
>
> Do we need memset here? Isn't this location is past the max location?
That is not required, I have modified it.
Attached v4 patch has the fixes for the same.
Regards,
Vignesh
From f7ffa65330038e1e41b4385f05a8b20c9ada02e2 Mon Sep 17 00:00:00 2001
From: vignesh <vignes...@gmail.com>
Date: Mon, 5 Apr 2021 19:01:03 +0530
Subject: [PATCH v4 1/3] Added total txns and total txn bytes to replication
statistics.
This adds the statistics about total transactions count and total transaction
data logically replicated to the decoding output plugin from ReorderBuffer.
Users can query the pg_stat_replication_slots view to check these stats.
This also includes changing char datatype to NameData datatype for slotname.
---
contrib/test_decoding/expected/stats.out | 79 +++++++++++++------
contrib/test_decoding/sql/stats.sql | 48 +++++++----
doc/src/sgml/monitoring.sgml | 23 ++++++
src/backend/catalog/system_views.sql | 2 +
src/backend/postmaster/pgstat.c | 38 +++++----
src/backend/replication/logical/logical.c | 30 ++++---
.../replication/logical/reorderbuffer.c | 18 +++++
src/backend/replication/slot.c | 7 +-
src/backend/utils/adt/pgstatfuncs.c | 10 ++-
src/include/catalog/pg_proc.dat | 6 +-
src/include/pgstat.h | 15 ++--
src/include/replication/reorderbuffer.h | 4 +
src/test/regress/expected/rules.out | 4 +-
13 files changed, 205 insertions(+), 79 deletions(-)
diff --git a/contrib/test_decoding/expected/stats.out b/contrib/test_decoding/expected/stats.out
index bca36fa903..bc8e601eab 100644
--- a/contrib/test_decoding/expected/stats.out
+++ b/contrib/test_decoding/expected/stats.out
@@ -8,7 +8,7 @@ SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot', 'test_d
CREATE TABLE stats_test(data text);
-- function to wait for counters to advance
-CREATE FUNCTION wait_for_decode_stats(check_reset bool) RETURNS void AS $$
+CREATE FUNCTION wait_for_decode_stats(check_reset bool, check_spill_txns bool) RETURNS void AS $$
DECLARE
start_time timestamptz := clock_timestamp();
updated bool;
@@ -16,12 +16,25 @@ BEGIN
-- we don't want to wait forever; loop will exit after 30 seconds
FOR i IN 1 .. 300 LOOP
- -- check to see if all updates have been reset/updated
- SELECT CASE WHEN check_reset THEN (spill_txns = 0)
- ELSE (spill_txns > 0)
- END
- INTO updated
- FROM pg_stat_replication_slots WHERE slot_name='regression_slot';
+ IF check_spill_txns THEN
+
+ -- check to see if all updates have been reset/updated
+ SELECT CASE WHEN check_reset THEN (spill_txns = 0)
+ ELSE (spill_txns > 0)
+ END
+ INTO updated
+ FROM pg_stat_replication_slots WHERE slot_name='regression_slot';
+
+ ELSE
+
+ -- check to see if all updates have been reset/updated
+ SELECT CASE WHEN check_reset THEN (total_txns = 0)
+ ELSE (total_txns > 0)
+ END
+ INTO updated
+ FROM pg_stat_replication_slots WHERE slot_name='regression_slot';
+
+ END IF;
exit WHEN updated;
@@ -51,16 +64,16 @@ SELECT count(*) FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL,
-- Check stats, wait for the stats collector to update. We can't test the
-- exact stats count as that can vary if any background transaction (say by
-- autovacuum) happens in parallel to the main transaction.
-SELECT wait_for_decode_stats(false);
+SELECT wait_for_decode_stats(false, true);
wait_for_decode_stats
-----------------------
(1 row)
-SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count FROM pg_stat_replication_slots;
- slot_name | spill_txns | spill_count
------------------+------------+-------------
- regression_slot | t | t
+SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
+ slot_name | spill_txns | spill_count | total_txns | total_bytes
+-----------------+------------+-------------+------------+-------------
+ regression_slot | t | t | t | t
(1 row)
-- reset the slot stats, and wait for stats collector to reset
@@ -70,16 +83,16 @@ SELECT pg_stat_reset_replication_slot('regression_slot');
(1 row)
-SELECT wait_for_decode_stats(true);
+SELECT wait_for_decode_stats(true, true);
wait_for_decode_stats
-----------------------
(1 row)
-SELECT slot_name, spill_txns, spill_count FROM pg_stat_replication_slots;
- slot_name | spill_txns | spill_count
------------------+------------+-------------
- regression_slot | 0 | 0
+SELECT slot_name, spill_txns, spill_count, total_txns, total_bytes FROM pg_stat_replication_slots;
+ slot_name | spill_txns | spill_count | total_txns | total_bytes
+-----------------+------------+-------------+------------+-------------
+ regression_slot | 0 | 0 | 0 | 0
(1 row)
-- decode and check stats again.
@@ -89,16 +102,36 @@ SELECT count(*) FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL,
5002
(1 row)
-SELECT wait_for_decode_stats(false);
+SELECT wait_for_decode_stats(false, true);
+ wait_for_decode_stats
+-----------------------
+
+(1 row)
+
+SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
+ slot_name | spill_txns | spill_count | total_txns | total_bytes
+-----------------+------------+-------------+------------+-------------
+ regression_slot | t | t | t | t
+(1 row)
+
+SELECT pg_stat_reset_replication_slot('regression_slot');
+ pg_stat_reset_replication_slot
+--------------------------------
+
+(1 row)
+
+-- non-spilled xact
+INSERT INTO stats_test values(generate_series(1, 10));
+SELECT wait_for_decode_stats(false, false);
wait_for_decode_stats
-----------------------
(1 row)
-SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count FROM pg_stat_replication_slots;
- slot_name | spill_txns | spill_count
------------------+------------+-------------
- regression_slot | t | t
+SELECT slot_name, spill_txns = 0 AS spill_txns, spill_count = 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
+ slot_name | spill_txns | spill_count | total_txns | total_bytes
+-----------------+------------+-------------+------------+-------------
+ regression_slot | f | f | t | t
(1 row)
-- Ensure stats can be repeatedly accessed using the same stats snapshot. See
@@ -117,7 +150,7 @@ SELECT slot_name FROM pg_stat_replication_slots;
(1 row)
COMMIT;
-DROP FUNCTION wait_for_decode_stats(bool);
+DROP FUNCTION wait_for_decode_stats(bool, bool);
DROP TABLE stats_test;
SELECT pg_drop_replication_slot('regression_slot');
pg_drop_replication_slot
diff --git a/contrib/test_decoding/sql/stats.sql b/contrib/test_decoding/sql/stats.sql
index 51294e48e8..8c34aeced1 100644
--- a/contrib/test_decoding/sql/stats.sql
+++ b/contrib/test_decoding/sql/stats.sql
@@ -6,7 +6,7 @@ SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot', 'test_d
CREATE TABLE stats_test(data text);
-- function to wait for counters to advance
-CREATE FUNCTION wait_for_decode_stats(check_reset bool) RETURNS void AS $$
+CREATE FUNCTION wait_for_decode_stats(check_reset bool, check_spill_txns bool) RETURNS void AS $$
DECLARE
start_time timestamptz := clock_timestamp();
updated bool;
@@ -14,12 +14,25 @@ BEGIN
-- we don't want to wait forever; loop will exit after 30 seconds
FOR i IN 1 .. 300 LOOP
- -- check to see if all updates have been reset/updated
- SELECT CASE WHEN check_reset THEN (spill_txns = 0)
- ELSE (spill_txns > 0)
- END
- INTO updated
- FROM pg_stat_replication_slots WHERE slot_name='regression_slot';
+ IF check_spill_txns THEN
+
+ -- check to see if all updates have been reset/updated
+ SELECT CASE WHEN check_reset THEN (spill_txns = 0)
+ ELSE (spill_txns > 0)
+ END
+ INTO updated
+ FROM pg_stat_replication_slots WHERE slot_name='regression_slot';
+
+ ELSE
+
+ -- check to see if all updates have been reset/updated
+ SELECT CASE WHEN check_reset THEN (total_txns = 0)
+ ELSE (total_txns > 0)
+ END
+ INTO updated
+ FROM pg_stat_replication_slots WHERE slot_name='regression_slot';
+
+ END IF;
exit WHEN updated;
@@ -46,18 +59,25 @@ SELECT count(*) FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL,
-- Check stats, wait for the stats collector to update. We can't test the
-- exact stats count as that can vary if any background transaction (say by
-- autovacuum) happens in parallel to the main transaction.
-SELECT wait_for_decode_stats(false);
-SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count FROM pg_stat_replication_slots;
+SELECT wait_for_decode_stats(false, true);
+SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
-- reset the slot stats, and wait for stats collector to reset
SELECT pg_stat_reset_replication_slot('regression_slot');
-SELECT wait_for_decode_stats(true);
-SELECT slot_name, spill_txns, spill_count FROM pg_stat_replication_slots;
+SELECT wait_for_decode_stats(true, true);
+SELECT slot_name, spill_txns, spill_count, total_txns, total_bytes FROM pg_stat_replication_slots;
-- decode and check stats again.
SELECT count(*) FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL, 'skip-empty-xacts', '1');
-SELECT wait_for_decode_stats(false);
-SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count FROM pg_stat_replication_slots;
+SELECT wait_for_decode_stats(false, true);
+SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
+
+SELECT pg_stat_reset_replication_slot('regression_slot');
+
+-- non-spilled xact
+INSERT INTO stats_test values(generate_series(1, 10));
+SELECT wait_for_decode_stats(false, false);
+SELECT slot_name, spill_txns = 0 AS spill_txns, spill_count = 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
-- Ensure stats can be repeatedly accessed using the same stats snapshot. See
-- https://postgr.es/m/20210317230447.c7uc4g3vbs4wi32i%40alap3.anarazel.de
@@ -66,6 +86,6 @@ SELECT slot_name FROM pg_stat_replication_slots;
SELECT slot_name FROM pg_stat_replication_slots;
COMMIT;
-DROP FUNCTION wait_for_decode_stats(bool);
+DROP FUNCTION wait_for_decode_stats(bool, bool);
DROP TABLE stats_test;
SELECT pg_drop_replication_slot('regression_slot');
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 56018745c8..a727f32fb2 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -2689,6 +2689,29 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
</entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>total_txns</structfield> <type>bigint</type>
+ </para>
+ <para>
+ Number of decoded transactions sent to the decoding output plugin for
+ this slot. This counter is used to maintain the top level transactions,
+ so the counter is not incremented for subtransactions.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>total_bytes</structfield><type>bigint</type>
+ </para>
+ <para>
+ Amount of decoded transactions data sent to the decoding output plugin
+ while decoding the changes from WAL for this slot. This can be used to
+ gauge the total amount of data sent during logical decoding.
+ </para>
+ </entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>stats_reset</structfield> <type>timestamp with time zone</type>
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 5f2541d316..e3991eb6f6 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -874,6 +874,8 @@ CREATE VIEW pg_stat_replication_slots AS
s.stream_txns,
s.stream_count,
s.stream_bytes,
+ s.total_txns,
+ s.total_bytes,
s.stats_reset
FROM pg_stat_get_replication_slots() AS s;
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 5ba776e789..89b9315af6 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -62,6 +62,7 @@
#include "storage/pg_shmem.h"
#include "storage/proc.h"
#include "storage/procsignal.h"
+#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/memutils.h"
#include "utils/ps_status.h"
@@ -1525,7 +1526,7 @@ pgstat_reset_replslot_counter(const char *name)
if (SlotIsPhysical(slot))
return;
- strlcpy(msg.m_slotname, name, NAMEDATALEN);
+ namestrcpy(&msg.m_slotname, name);
msg.clearall = false;
}
else
@@ -1743,10 +1744,7 @@ pgstat_report_tempfile(size_t filesize)
* ----------
*/
void
-pgstat_report_replslot(const char *slotname, PgStat_Counter spilltxns,
- PgStat_Counter spillcount, PgStat_Counter spillbytes,
- PgStat_Counter streamtxns, PgStat_Counter streamcount,
- PgStat_Counter streambytes)
+pgstat_report_replslot(const PgStat_ReplSlotStats *repSlotStat)
{
PgStat_MsgReplSlot msg;
@@ -1754,14 +1752,16 @@ pgstat_report_replslot(const char *slotname, PgStat_Counter spilltxns,
* Prepare and send the message
*/
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_REPLSLOT);
- strlcpy(msg.m_slotname, slotname, NAMEDATALEN);
+ namestrcpy(&msg.m_slotname, NameStr(repSlotStat->slotname));
msg.m_drop = false;
- msg.m_spill_txns = spilltxns;
- msg.m_spill_count = spillcount;
- msg.m_spill_bytes = spillbytes;
- msg.m_stream_txns = streamtxns;
- msg.m_stream_count = streamcount;
- msg.m_stream_bytes = streambytes;
+ msg.m_spill_txns = repSlotStat->spill_txns;
+ msg.m_spill_count = repSlotStat->spill_count;;
+ msg.m_spill_bytes = repSlotStat->spill_bytes;
+ msg.m_stream_txns = repSlotStat->stream_txns;
+ msg.m_stream_count = repSlotStat->stream_count;
+ msg.m_stream_bytes = repSlotStat->stream_bytes;
+ msg.m_total_txns = repSlotStat->total_txns;
+ msg.m_total_bytes = repSlotStat->total_bytes;
pgstat_send(&msg, sizeof(PgStat_MsgReplSlot));
}
@@ -1777,7 +1777,7 @@ pgstat_report_replslot_drop(const char *slotname)
PgStat_MsgReplSlot msg;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_REPLSLOT);
- strlcpy(msg.m_slotname, slotname, NAMEDATALEN);
+ namestrcpy(&msg.m_slotname, slotname);
msg.m_drop = true;
pgstat_send(&msg, sizeof(PgStat_MsgReplSlot));
}
@@ -5049,7 +5049,7 @@ pgstat_recv_resetreplslotcounter(PgStat_MsgResetreplslotcounter *msg,
else
{
/* Get the index of replication slot statistics to reset */
- idx = pgstat_replslot_index(msg->m_slotname, false);
+ idx = pgstat_replslot_index(NameStr(msg->m_slotname), false);
/*
* Nothing to do if the given slot entry is not found. This could
@@ -5347,7 +5347,7 @@ pgstat_recv_replslot(PgStat_MsgReplSlot *msg, int len)
* Get the index of replication slot statistics. On dropping, we don't
* create the new statistics.
*/
- idx = pgstat_replslot_index(msg->m_slotname, !msg->m_drop);
+ idx = pgstat_replslot_index(NameStr(msg->m_slotname), !msg->m_drop);
/*
* The slot entry is not found or there is no space to accommodate the new
@@ -5379,6 +5379,8 @@ pgstat_recv_replslot(PgStat_MsgReplSlot *msg, int len)
replSlotStats[idx].stream_txns += msg->m_stream_txns;
replSlotStats[idx].stream_count += msg->m_stream_count;
replSlotStats[idx].stream_bytes += msg->m_stream_bytes;
+ replSlotStats[idx].total_txns += msg->m_total_txns;
+ replSlotStats[idx].total_bytes += msg->m_total_bytes;
}
}
@@ -5572,7 +5574,7 @@ pgstat_replslot_index(const char *name, bool create_it)
Assert(nReplSlotStats <= max_replication_slots);
for (i = 0; i < nReplSlotStats; i++)
{
- if (strcmp(replSlotStats[i].slotname, name) == 0)
+ if (namestrcmp(&replSlotStats[i].slotname, name) == 0)
return i; /* found */
}
@@ -5585,7 +5587,7 @@ pgstat_replslot_index(const char *name, bool create_it)
/* Register new slot */
memset(&replSlotStats[nReplSlotStats], 0, sizeof(PgStat_ReplSlotStats));
- strlcpy(replSlotStats[nReplSlotStats].slotname, name, NAMEDATALEN);
+ namestrcpy(&replSlotStats[nReplSlotStats].slotname, name);
return nReplSlotStats++;
}
@@ -5606,6 +5608,8 @@ pgstat_reset_replslot(int i, TimestampTz ts)
replSlotStats[i].stream_txns = 0;
replSlotStats[i].stream_count = 0;
replSlotStats[i].stream_bytes = 0;
+ replSlotStats[i].total_txns = 0;
+ replSlotStats[i].total_bytes = 0;
replSlotStats[i].stat_reset_timestamp = ts;
}
diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c
index 2f6803637b..d0ad694477 100644
--- a/src/backend/replication/logical/logical.c
+++ b/src/backend/replication/logical/logical.c
@@ -1763,30 +1763,42 @@ void
UpdateDecodingStats(LogicalDecodingContext *ctx)
{
ReorderBuffer *rb = ctx->reorder;
+ PgStat_ReplSlotStats repSlotStat;
/*
- * Nothing to do if we haven't spilled or streamed anything since the last
- * time the stats has been sent.
+ * Nothing to do if we don't have any replication stats to be sent.
*/
- if (rb->spillBytes <= 0 && rb->streamBytes <= 0)
+ if (rb->spillBytes <= 0 && rb->streamBytes <= 0 && rb->totalBytes <= 0)
return;
- elog(DEBUG2, "UpdateDecodingStats: updating stats %p %lld %lld %lld %lld %lld %lld",
+ elog(DEBUG2, "UpdateDecodingStats: updating stats %p %lld %lld %lld %lld %lld %lld %lld %lld",
rb,
(long long) rb->spillTxns,
(long long) rb->spillCount,
(long long) rb->spillBytes,
(long long) rb->streamTxns,
(long long) rb->streamCount,
- (long long) rb->streamBytes);
-
- pgstat_report_replslot(NameStr(ctx->slot->data.name),
- rb->spillTxns, rb->spillCount, rb->spillBytes,
- rb->streamTxns, rb->streamCount, rb->streamBytes);
+ (long long) rb->streamBytes,
+ (long long) rb->totalTxns,
+ (long long) rb->totalBytes);
+
+ namestrcpy(&repSlotStat.slotname, NameStr(ctx->slot->data.name));
+ repSlotStat.spill_txns = rb->spillTxns;
+ repSlotStat.spill_count = rb->spillCount;
+ repSlotStat.spill_bytes = rb->spillBytes;
+ repSlotStat.stream_txns = rb->streamTxns;
+ repSlotStat.stream_count = rb->streamCount;
+ repSlotStat.stream_bytes = rb->streamBytes;
+ repSlotStat.total_txns = rb->totalTxns;
+ repSlotStat.total_bytes = rb->totalBytes;
+
+ pgstat_report_replslot(&repSlotStat);
rb->spillTxns = 0;
rb->spillCount = 0;
rb->spillBytes = 0;
rb->streamTxns = 0;
rb->streamCount = 0;
rb->streamBytes = 0;
+ rb->totalTxns = 0;
+ rb->totalBytes = 0;
}
diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index 52d06285a2..7899060f02 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -350,6 +350,8 @@ ReorderBufferAllocate(void)
buffer->streamTxns = 0;
buffer->streamCount = 0;
buffer->streamBytes = 0;
+ buffer->totalTxns = 0;
+ buffer->totalBytes = 0;
buffer->current_restart_decoding_lsn = InvalidXLogRecPtr;
@@ -659,6 +661,7 @@ ReorderBufferTXNByXid(ReorderBuffer *rb, TransactionId xid, bool create,
dlist_push_tail(&rb->toplevel_by_lsn, &txn->node);
AssertTXNLsnOrder(rb);
}
+
}
else
txn = NULL; /* not found and not asked to create */
@@ -2051,6 +2054,17 @@ ReorderBufferProcessTXN(ReorderBuffer *rb, ReorderBufferTXN *txn,
rb->begin(rb, txn);
}
+ /*
+ * Update total transaction count and total transaction bytes, if
+ * transaction is streamed or spilled it will be updated while the
+ * transaction gets spilled or streamed.
+ */
+ if (!rb->streamBytes && !rb->spillBytes)
+ {
+ rb->totalTxns++;
+ rb->totalBytes += rb->size;
+ }
+
ReorderBufferIterTXNInit(rb, txn, &iterstate);
while ((change = ReorderBufferIterTXNNext(rb, iterstate)) != NULL)
{
@@ -3524,9 +3538,11 @@ ReorderBufferSerializeTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
{
rb->spillCount += 1;
rb->spillBytes += size;
+ rb->totalBytes += size;
/* don't consider already serialized transactions */
rb->spillTxns += (rbtxn_is_serialized(txn) || rbtxn_is_serialized_clear(txn)) ? 0 : 1;
+ rb->totalTxns += (rbtxn_is_serialized(txn) || rbtxn_is_serialized_clear(txn)) ? 0 : 1;
}
Assert(spilled == txn->nentries_mem);
@@ -3892,9 +3908,11 @@ ReorderBufferStreamTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
rb->streamCount += 1;
rb->streamBytes += stream_bytes;
+ rb->totalBytes += stream_bytes;
/* Don't consider already streamed transaction. */
rb->streamTxns += (txn_is_streamed) ? 0 : 1;
+ rb->totalTxns += (txn_is_streamed) ? 0 : 1;
Assert(dlist_is_empty(&txn->changes));
Assert(txn->nentries == 0);
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index 75a087c2f9..f61b163f78 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -328,7 +328,12 @@ ReplicationSlotCreate(const char *name, bool db_specific,
* ReplicationSlotAllocationLock.
*/
if (SlotIsLogical(slot))
- pgstat_report_replslot(NameStr(slot->data.name), 0, 0, 0, 0, 0, 0);
+ {
+ PgStat_ReplSlotStats repSlotStat;
+ MemSet(&repSlotStat, 0, sizeof(PgStat_ReplSlotStats));
+ namestrcpy(&repSlotStat.slotname, NameStr(slot->data.name));
+ pgstat_report_replslot(&repSlotStat);
+ }
/*
* Now that the slot has been marked as in_use and active, it's safe to
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 9ffbca685c..54eb3d1538 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -2279,7 +2279,7 @@ pg_stat_get_archiver(PG_FUNCTION_ARGS)
Datum
pg_stat_get_replication_slots(PG_FUNCTION_ARGS)
{
-#define PG_STAT_GET_REPLICATION_SLOT_COLS 8
+#define PG_STAT_GET_REPLICATION_SLOT_COLS 10
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
TupleDesc tupdesc;
Tuplestorestate *tupstore;
@@ -2323,18 +2323,20 @@ pg_stat_get_replication_slots(PG_FUNCTION_ARGS)
MemSet(values, 0, sizeof(values));
MemSet(nulls, 0, sizeof(nulls));
- values[0] = PointerGetDatum(cstring_to_text(s->slotname));
+ values[0] = CStringGetTextDatum(NameStr(s->slotname));
values[1] = Int64GetDatum(s->spill_txns);
values[2] = Int64GetDatum(s->spill_count);
values[3] = Int64GetDatum(s->spill_bytes);
values[4] = Int64GetDatum(s->stream_txns);
values[5] = Int64GetDatum(s->stream_count);
values[6] = Int64GetDatum(s->stream_bytes);
+ values[7] = Int64GetDatum(s->total_txns);
+ values[8] = Int64GetDatum(s->total_bytes);
if (s->stat_reset_timestamp == 0)
- nulls[7] = true;
+ nulls[9] = true;
else
- values[7] = TimestampTzGetDatum(s->stat_reset_timestamp);
+ values[9] = TimestampTzGetDatum(s->stat_reset_timestamp);
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 4309fa40dd..95be4db2b2 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5311,9 +5311,9 @@
proname => 'pg_stat_get_replication_slots', prorows => '10',
proisstrict => 'f', proretset => 't', provolatile => 's', proparallel => 'r',
prorettype => 'record', proargtypes => '',
- proallargtypes => '{text,int8,int8,int8,int8,int8,int8,timestamptz}',
- proargmodes => '{o,o,o,o,o,o,o,o}',
- proargnames => '{slot_name,spill_txns,spill_count,spill_bytes,stream_txns,stream_count,stream_bytes,stats_reset}',
+ proallargtypes => '{text,int8,int8,int8,int8,int8,int8,int8,int8,timestamptz}',
+ proargmodes => '{o,o,o,o,o,o,o,o,o,o}',
+ proargnames => '{slot_name,spill_txns,spill_count,spill_bytes,stream_txns,stream_count,stream_bytes,total_txns,total_bytes,stats_reset}',
prosrc => 'pg_stat_get_replication_slots' },
{ oid => '6118', descr => 'statistics: information about subscription',
proname => 'pg_stat_get_subscription', prorows => '10', proisstrict => 'f',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 7cd137506e..63b740ab40 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -378,7 +378,7 @@ typedef struct PgStat_MsgResetslrucounter
typedef struct PgStat_MsgResetreplslotcounter
{
PgStat_MsgHdr m_hdr;
- char m_slotname[NAMEDATALEN];
+ NameData m_slotname;
bool clearall;
} PgStat_MsgResetreplslotcounter;
@@ -506,7 +506,7 @@ typedef struct PgStat_MsgSLRU
typedef struct PgStat_MsgReplSlot
{
PgStat_MsgHdr m_hdr;
- char m_slotname[NAMEDATALEN];
+ NameData m_slotname;
bool m_drop;
PgStat_Counter m_spill_txns;
PgStat_Counter m_spill_count;
@@ -514,6 +514,8 @@ typedef struct PgStat_MsgReplSlot
PgStat_Counter m_stream_txns;
PgStat_Counter m_stream_count;
PgStat_Counter m_stream_bytes;
+ PgStat_Counter m_total_txns;
+ PgStat_Counter m_total_bytes;
} PgStat_MsgReplSlot;
@@ -871,13 +873,15 @@ typedef struct PgStat_SLRUStats
*/
typedef struct PgStat_ReplSlotStats
{
- char slotname[NAMEDATALEN];
+ NameData slotname;
PgStat_Counter spill_txns;
PgStat_Counter spill_count;
PgStat_Counter spill_bytes;
PgStat_Counter stream_txns;
PgStat_Counter stream_count;
PgStat_Counter stream_bytes;
+ PgStat_Counter total_txns;
+ PgStat_Counter total_bytes;
TimestampTz stat_reset_timestamp;
} PgStat_ReplSlotStats;
@@ -980,10 +984,7 @@ extern void pgstat_report_recovery_conflict(int reason);
extern void pgstat_report_deadlock(void);
extern void pgstat_report_checksum_failures_in_db(Oid dboid, int failurecount);
extern void pgstat_report_checksum_failure(void);
-extern void pgstat_report_replslot(const char *slotname, PgStat_Counter spilltxns,
- PgStat_Counter spillcount, PgStat_Counter spillbytes,
- PgStat_Counter streamtxns, PgStat_Counter streamcount,
- PgStat_Counter streambytes);
+extern void pgstat_report_replslot(const PgStat_ReplSlotStats *repSlotStat);
extern void pgstat_report_replslot_drop(const char *slotname);
extern void pgstat_initialize(void);
diff --git a/src/include/replication/reorderbuffer.h b/src/include/replication/reorderbuffer.h
index 565a961d6a..a372b70b7d 100644
--- a/src/include/replication/reorderbuffer.h
+++ b/src/include/replication/reorderbuffer.h
@@ -618,6 +618,10 @@ struct ReorderBuffer
int64 streamTxns; /* number of transactions streamed */
int64 streamCount; /* streaming invocation counter */
int64 streamBytes; /* amount of data streamed */
+
+ /* Statistics about all the replicated transactions */
+ int64 totalTxns; /* total number of transactions replicated */
+ int64 totalBytes; /* total amount of data replicated */
};
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 9b59a7b4a5..f0eea8b18f 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2056,8 +2056,10 @@ pg_stat_replication_slots| SELECT s.slot_name,
s.stream_txns,
s.stream_count,
s.stream_bytes,
+ s.total_txns,
+ s.total_bytes,
s.stats_reset
- FROM pg_stat_get_replication_slots() s(slot_name, spill_txns, spill_count, spill_bytes, stream_txns, stream_count, stream_bytes, stats_reset);
+ FROM pg_stat_get_replication_slots() s(slot_name, spill_txns, spill_count, spill_bytes, stream_txns, stream_count, stream_bytes, total_txns, total_bytes, stats_reset);
pg_stat_slru| SELECT s.name,
s.blks_zeroed,
s.blks_hit,
--
2.25.1
From a616512f2d30d9211f21f5405485a6848d529381 Mon Sep 17 00:00:00 2001
From: vignesh <vignes...@gmail.com>
Date: Mon, 5 Apr 2021 18:17:21 +0530
Subject: [PATCH v4 2/3] Added tests for verification of logical replication
statistics.
Added tests for verification of logical replication statistics after
restart of server.
---
contrib/test_decoding/Makefile | 2 +
contrib/test_decoding/t/001_repl_stats.pl | 113 ++++++++++++++++++++++
2 files changed, 115 insertions(+)
create mode 100644 contrib/test_decoding/t/001_repl_stats.pl
diff --git a/contrib/test_decoding/Makefile b/contrib/test_decoding/Makefile
index c5e28ce5cc..9a31e0b879 100644
--- a/contrib/test_decoding/Makefile
+++ b/contrib/test_decoding/Makefile
@@ -17,6 +17,8 @@ ISOLATION_OPTS = --temp-config $(top_srcdir)/contrib/test_decoding/logical.conf
# typical installcheck users do not have (e.g. buildfarm clients).
NO_INSTALLCHECK = 1
+TAP_TESTS = 1
+
ifdef USE_PGXS
PG_CONFIG = pg_config
PGXS := $(shell $(PG_CONFIG) --pgxs)
diff --git a/contrib/test_decoding/t/001_repl_stats.pl b/contrib/test_decoding/t/001_repl_stats.pl
new file mode 100644
index 0000000000..11ffe0ca3e
--- /dev/null
+++ b/contrib/test_decoding/t/001_repl_stats.pl
@@ -0,0 +1,113 @@
+# Test replication statistics data in pg_stat_replication_slots is sane after
+# drop replication slot and restart.
+use strict;
+use warnings;
+use File::Path qw(rmtree);
+use PostgresNode;
+use TestLib;
+use Test::More tests => 2;
+
+# Test set-up
+my $node = get_new_node('test');
+$node->init(allows_streaming => 'logical');
+$node->append_conf('postgresql.conf', 'synchronous_commit = on');
+$node->start;
+
+$node->safe_psql('postgres', q(CREATE FUNCTION wait_for_decode_stats(check_slot_name text) RETURNS void AS $$
+DECLARE
+ start_time timestamptz := clock_timestamp();
+ txn_count bool;
+BEGIN
+ -- we don't want to wait forever; loop will exit after 30 seconds
+ FOR i IN 1 .. 300 LOOP
+
+ -- check to see if all updates have been reset/updated
+ SELECT (total_txns > 0) INTO txn_count
+ FROM pg_stat_replication_slots WHERE slot_name=check_slot_name;
+
+ exit WHEN txn_count;
+
+ -- wait a little
+ perform pg_sleep_for('100 milliseconds');
+
+ -- reset stats snapshot so we can test again
+ perform pg_stat_clear_snapshot();
+
+ END LOOP;
+
+ -- report time waited in postmaster log (where it won't change test output)
+ RAISE LOG 'wait_for_decode_stats delayed % seconds',
+ extract(epoch from clock_timestamp() - start_time);
+END
+$$ LANGUAGE plpgsql;
+));
+
+# Create table.
+$node->safe_psql('postgres',
+ "CREATE TABLE test_repl_stat(col1 int)");
+
+# Create replication slots.
+$node->safe_psql('postgres',
+ "SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot1', 'test_decoding')");
+$node->safe_psql('postgres',
+ "SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot2', 'test_decoding')");
+$node->safe_psql('postgres',
+ "SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot3', 'test_decoding')");
+$node->safe_psql('postgres',
+ "SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot4', 'test_decoding')");
+
+# Insert some data.
+$node->safe_psql('postgres', "INSERT INTO test_repl_stat values(generate_series(1, 5));");
+
+$node->safe_psql('postgres',
+ "SELECT data FROM pg_logical_slot_get_changes('regression_slot1', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1')");
+$node->safe_psql('postgres',
+ "SELECT data FROM pg_logical_slot_get_changes('regression_slot2', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1')");
+$node->safe_psql('postgres',
+ "SELECT data FROM pg_logical_slot_get_changes('regression_slot3', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1')");
+$node->safe_psql('postgres',
+ "SELECT data FROM pg_logical_slot_get_changes('regression_slot4', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1')");
+
+# Wait for the statistics to be updated.
+$node->safe_psql('postgres', "SELECT wait_for_decode_stats('regression_slot1')");
+$node->safe_psql('postgres', "SELECT wait_for_decode_stats('regression_slot2')");
+$node->safe_psql('postgres', "SELECT wait_for_decode_stats('regression_slot3')");
+$node->safe_psql('postgres', "SELECT wait_for_decode_stats('regression_slot4')");
+
+# Test to verify replication statistics data is updated in
+# pg_stat_replication_slots statistics view.
+my $result = $node->safe_psql('postgres',
+ "SELECT slot_name, total_txns > 0 AS total_txn, total_bytes > 0 AS total_bytes
+ FROM pg_stat_replication_slots ORDER BY slot_name"
+);
+is($result, qq(regression_slot1|t|t
+regression_slot2|t|t
+regression_slot3|t|t
+regression_slot4|t|t), 'check replication statistics are updated');
+
+# Test to drop one of the replication slot and verify replication statistics data is
+# fine after restart.
+$node->safe_psql('postgres', "SELECT pg_drop_replication_slot('regression_slot4')");
+
+$node->stop;
+$node->start;
+
+# Verify statistics data present in pg_stat_replication_slots are sane after
+# restart.
+$result = $node->safe_psql('postgres',
+ "SELECT slot_name, total_txns > 0 AS total_txn, total_bytes > 0 AS total_bytes
+ FROM pg_stat_replication_slots ORDER BY slot_name"
+);
+is($result, qq(regression_slot1|t|t
+regression_slot2|t|t
+regression_slot3|t|t), 'check replication statistics are updated');
+
+# cleanup
+$node->safe_psql('postgres', "DROP TABLE test_repl_stat");
+$node->safe_psql('postgres', "DROP FUNCTION wait_for_decode_stats(TEXT)");
+$node->safe_psql('postgres', "SELECT pg_drop_replication_slot('regression_slot1')");
+$node->safe_psql('postgres', "SELECT pg_drop_replication_slot('regression_slot2')");
+$node->safe_psql('postgres', "SELECT pg_drop_replication_slot('regression_slot3')");
+
+# shutdown
+$node->stop;
--
2.25.1
From d3d93d7a604102d77b4e220a6453d39686eb271d Mon Sep 17 00:00:00 2001
From: vignesh <vignes...@gmail.com>
Date: Wed, 7 Apr 2021 13:07:26 +0530
Subject: [PATCH v4 3/3] Handle overwriting of replication slot statistic
issue.
There is a remote scenario where one of the replication slots is dropped and
the drop slot statistics message is not received by the statistic collector
process, now if the max_replication_slots is reduced to the actual number of
replication slots that are in use and the server is re-started then the
statistics process will not be aware of this and the statistic collector
process will write beyond the slots available, fixed it by skipping the
replication slot statistic that are after max_replication_slot.
---
contrib/test_decoding/t/001_repl_stats.pl | 24 +++++++++++++++++++++--
src/backend/postmaster/pgstat.c | 18 +++++++++++++++++
2 files changed, 40 insertions(+), 2 deletions(-)
diff --git a/contrib/test_decoding/t/001_repl_stats.pl b/contrib/test_decoding/t/001_repl_stats.pl
index 11ffe0ca3e..4a1b113c41 100644
--- a/contrib/test_decoding/t/001_repl_stats.pl
+++ b/contrib/test_decoding/t/001_repl_stats.pl
@@ -5,7 +5,7 @@ use warnings;
use File::Path qw(rmtree);
use PostgresNode;
use TestLib;
-use Test::More tests => 2;
+use Test::More tests => 3;
# Test set-up
my $node = get_new_node('test');
@@ -102,12 +102,32 @@ is($result, qq(regression_slot1|t|t
regression_slot2|t|t
regression_slot3|t|t), 'check replication statistics are updated');
+# Test to remove one of the replication slots and adjust max_replication_slots
+# accordingly to the number of slots and verify replication statistics data is
+# fine after restart.
+$node->stop;
+my $datadir = $node->data_dir;
+my $slot3_replslotdir = "$datadir/pg_replslot/regression_slot3";
+
+rmtree($slot3_replslotdir);
+
+$node->append_conf('postgresql.conf', 'max_replication_slots = 2');
+$node->start;
+
+# Verify statistics data present in pg_stat_replication_slots are sane after
+# restart.
+$result = $node->safe_psql('postgres',
+ "SELECT slot_name, total_txns > 0 AS total_txn, total_bytes > 0 AS total_bytes
+ FROM pg_stat_replication_slots ORDER BY slot_name"
+);
+is($result, qq(regression_slot1|t|t
+regression_slot2|t|t), 'check replication statistics are updated');
+
# cleanup
$node->safe_psql('postgres', "DROP TABLE test_repl_stat");
$node->safe_psql('postgres', "DROP FUNCTION wait_for_decode_stats(TEXT)");
$node->safe_psql('postgres', "SELECT pg_drop_replication_slot('regression_slot1')");
$node->safe_psql('postgres', "SELECT pg_drop_replication_slot('regression_slot2')");
-$node->safe_psql('postgres', "SELECT pg_drop_replication_slot('regression_slot3')");
# shutdown
$node->stop;
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 89b9315af6..c292d4ab94 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -4069,6 +4069,24 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
* slot follows.
*/
case 'R':
+ /*
+ * There is a remote scenario where one of the replication slots
+ * is dropped and the drop slot statistics message is not
+ * received by the statistic collector process, now if the
+ * max_replication_slots is reduced to the actual number of
+ * replication slots that are in use and the server is
+ * re-started then the statistics process will not be aware of
+ * this. To avoid writing beyond the max_replication_slots
+ * this replication slot statistic information will be skipped.
+ */
+ if (max_replication_slots == nReplSlotStats)
+ {
+ ereport(pgStatRunningInCollector ? LOG : WARNING,
+ (errmsg("skipping \"%s\" replication slot statistics as pg_stat_replication_slots does not have enough slots",
+ NameStr(replSlotStats[nReplSlotStats].slotname))));
+ goto done;
+ }
+
if (fread(&replSlotStats[nReplSlotStats], 1, sizeof(PgStat_ReplSlotStats), fpin)
!= sizeof(PgStat_ReplSlotStats))
{
--
2.25.1
