On Thu, Apr 1, 2021 at 5:58 PM Amit Kapila <amit.kapil...@gmail.com> wrote:
>
> On Thu, Apr 1, 2021 at 3:43 PM vignesh C <vignes...@gmail.com> wrote:
> >
> > On Wed, Mar 31, 2021 at 11:32 AM vignesh C <vignes...@gmail.com> wrote:
> > >
> > > On Tue, Mar 30, 2021 at 11:00 AM Andres Freund <and...@anarazel.de> wrote:
> > > >
> > > > Hi,
> > > >
> > > > On 2021-03-30 10:13:29 +0530, vignesh C wrote:
> > > > > On Tue, Mar 30, 2021 at 6:28 AM Andres Freund <and...@anarazel.de>
> > > > > wrote:
> > > > > > Any chance you could write a tap test exercising a few of these
> > > > > > cases?
> > > > >
> > > > > I can try to write a patch for this if nobody objects.
> > > >
> > > > Cool!
> > > >
> > >
> > > Attached a patch which has the test for the first scenario.
> > >
> > > > > > E.g. things like:
> > > > > >
> > > > > > - create a few slots, drop one of them, shut down, start up, verify
> > > > > > stats are still sane
> > > > > > - create a few slots, shut down, manually remove a slot, lower
> > > > > > max_replication_slots, start up
> > > > >
> > > > > Here by "manually remove a slot", do you mean to remove the slot
> > > > > manually from the pg_replslot folder?
> > > >
> > > > Yep - thereby allowing max_replication_slots after the shutdown/start to
> > > > be lower than the number of slots-stats objects.
> > >
> > > I have not included the 2nd test in the patch as the test fails with
> > > following warnings and also displays the statistics of the removed
> > > slot:
> > > WARNING: problem in alloc set Statistics snapshot: detected write
> > > past chunk end in block 0x55d038b8e410, chunk 0x55d038b8e438
> > > WARNING: problem in alloc set Statistics snapshot: detected write
> > > past chunk end in block 0x55d038b8e410, chunk 0x55d038b8e438
> > >
> > > This happens because the statistics file has an additional slot
> > > present even though the replication slot was removed. I felt this
> > > issue should be fixed. I will try to fix this issue and send the
> > > second test along with the fix.
> >
> > I felt from the statistics collector process, there is no way in which
> > we can identify if the replication slot is present or not because the
> > statistic collector process does not have access to shared memory.
> > Anything that the statistic collector process does independently by
> > traversing and removing the statistics of the replication slot
> > exceeding the max_replication_slot has its drawback of removing some
> > valid replication slot's statistics data.
> > Any thoughts on how we can identify the replication slot which has been
> > dropped?
> > Can someone point me to the shared stats patch link with which message
> > loss can be avoided. I wanted to see a scenario where something like
> > the slot is dropped but the statistics are not updated because of an
> > immediate shutdown or server going down abruptly can occur or not with
> > the shared stats patch.
> >
>
> I don't think it is easy to simulate a scenario where the 'drop'
> message is dropped and I think that is why the test contains the step
> to manually remove the slot. At this stage, you can probably provide a
> test patch and a code-fix patch where it just drops the extra slots
> from the stats file. That will allow us to test it with a shared
> memory stats patch on which Andres and Horiguchi-San are working. If
> we still continue to pursue with current approach then as Andres
> suggested we might send additional information from
> RestoreSlotFromDisk to keep it in sync.
Thanks for your comments, Attached patch has the fix for the same.
Also attached a couple of more patches which addresses the comments
which Andres had listed i.e changing char to NameData type and also to
display the unspilled/unstreamed transaction information in the
replication statistics.
Thoughts?
Regards,
Vignesh
From 53d58eeca5335485aba96b57bea68b5807c7bcc4 Mon Sep 17 00:00:00 2001
From: vignesh <vignes...@gmail.com>
Date: Thu, 1 Apr 2021 21:15:47 +0530
Subject: [PATCH v1 1/4] Changed char datatype to NameData datatype for
slotname.
Changed char datatype to NameData datatype for slotname.
---
src/backend/postmaster/pgstat.c | 15 ++++++++-------
src/backend/utils/adt/pgstatfuncs.c | 2 +-
src/include/pgstat.h | 6 +++---
3 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 4b9bcd2b41..132fdef78c 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -64,6 +64,7 @@
#include "storage/procsignal.h"
#include "storage/sinvaladt.h"
#include "utils/ascii.h"
+#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/memutils.h"
#include "utils/ps_status.h"
@@ -1555,7 +1556,7 @@ 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
@@ -1782,7 +1783,7 @@ pgstat_report_replslot(const char *slotname, int spilltxns, int spillcount,
* Prepare and send the message
*/
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_REPLSLOT);
- strlcpy(msg.m_slotname, slotname, NAMEDATALEN);
+ namestrcpy(&msg.m_slotname, slotname);
msg.m_drop = false;
msg.m_spill_txns = spilltxns;
msg.m_spill_count = spillcount;
@@ -1805,7 +1806,7 @@ 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));
}
@@ -6758,7 +6759,7 @@ 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(msg->m_slotname.data, false);
/*
* Nothing to do if the given slot entry is not found. This could
@@ -7056,7 +7057,7 @@ 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(msg->m_slotname.data, !msg->m_drop);
/*
* The slot entry is not found or there is no space to accommodate the new
@@ -7325,7 +7326,7 @@ 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 */
}
@@ -7338,7 +7339,7 @@ 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++;
}
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 5102227a60..2ce8e1fd2d 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -2323,7 +2323,7 @@ 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] = PointerGetDatum(cstring_to_text(s->slotname.data));
values[1] = Int64GetDatum(s->spill_txns);
values[2] = Int64GetDatum(s->spill_count);
values[3] = Int64GetDatum(s->spill_bytes);
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index d699502cd9..10784f947e 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -379,7 +379,7 @@ typedef struct PgStat_MsgResetslrucounter
typedef struct PgStat_MsgResetreplslotcounter
{
PgStat_MsgHdr m_hdr;
- char m_slotname[NAMEDATALEN];
+ NameData m_slotname;
bool clearall;
} PgStat_MsgResetreplslotcounter;
@@ -507,7 +507,7 @@ 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;
@@ -872,7 +872,7 @@ 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;
--
2.25.1
From 2a0e168194fa446600e84301f94d8ee2b4b39221 Mon Sep 17 00:00:00 2001
From: vignesh <vignes...@gmail.com>
Date: Thu, 1 Apr 2021 19:47:01 +0530
Subject: [PATCH v1 2/4] Added tests for verification of logical replication
statistics.
Added tests for verification of logical replication statistics after
restart of server.
---
src/test/subscription/t/020_repl_stats.pl | 161 ++++++++++++++++++++++
1 file changed, 161 insertions(+)
create mode 100644 src/test/subscription/t/020_repl_stats.pl
diff --git a/src/test/subscription/t/020_repl_stats.pl b/src/test/subscription/t/020_repl_stats.pl
new file mode 100644
index 0000000000..4be58d417a
--- /dev/null
+++ b/src/test/subscription/t/020_repl_stats.pl
@@ -0,0 +1,161 @@
+# Test replication statistics data gets updated in pg_stat_replication_slots
+# view for logical replication.
+use strict;
+use warnings;
+use PostgresNode;
+use TestLib;
+use Test::More tests => 5;
+
+# Create publisher node.
+my $node_publisher = get_new_node('publisher');
+$node_publisher->init(allows_streaming => 'logical');
+$node_publisher->append_conf('postgresql.conf', 'logical_decoding_work_mem = 64kB');
+$node_publisher->start;
+
+# Create subscriber nodes.
+my $node_subscriber1 = get_new_node('subscriber1');
+$node_subscriber1->init(allows_streaming => 'logical');
+$node_subscriber1->start;
+
+my $node_subscriber2 = get_new_node('subscriber2');
+$node_subscriber2->init(allows_streaming => 'logical');
+$node_subscriber2->start;
+
+my $node_subscriber3 = get_new_node('subscriber3');
+$node_subscriber3->init(allows_streaming => 'logical');
+$node_subscriber3->start;
+
+# Create table on publisher.
+$node_publisher->safe_psql('postgres',
+ "CREATE TABLE test_tab (a int primary key, b varchar)");
+
+# Create table on subscribers.
+$node_subscriber1->safe_psql('postgres', "CREATE TABLE test_tab (a int primary key, b text, c timestamptz DEFAULT now(), d bigint DEFAULT 999)");
+$node_subscriber2->safe_psql('postgres', "CREATE TABLE test_tab (a int primary key, b text, c timestamptz DEFAULT now(), d bigint DEFAULT 999)");
+$node_subscriber3->safe_psql('postgres', "CREATE TABLE test_tab (a int primary key, b text, c timestamptz DEFAULT now(), d bigint DEFAULT 999)");
+
+# Setup logical replication.
+my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
+$node_publisher->safe_psql('postgres', "CREATE PUBLICATION tap_pub FOR TABLE test_tab");
+
+my $appname1 = 'tap_sub1';
+$node_subscriber1->safe_psql('postgres',
+ "CREATE SUBSCRIPTION tap_sub1
+ CONNECTION '$publisher_connstr
+ application_name=$appname1'
+ PUBLICATION tap_pub WITH (streaming = on)"
+);
+
+my $appname2 = 'tap_sub2';
+$node_subscriber2->safe_psql('postgres',
+ "CREATE SUBSCRIPTION tap_sub2
+ CONNECTION '$publisher_connstr
+ application_name=$appname2'
+ PUBLICATION tap_pub WITH (streaming = off)"
+);
+
+my $appname3 = 'tap_sub3';
+$node_subscriber3->safe_psql('postgres',
+ "CREATE SUBSCRIPTION tap_sub3
+ CONNECTION '$publisher_connstr
+ application_name=$appname3'
+ PUBLICATION tap_pub WITH (streaming = off)"
+);
+
+$node_publisher->wait_for_catchup($appname1);
+$node_publisher->wait_for_catchup($appname2);
+$node_publisher->wait_for_catchup($appname3);
+
+# Interleave a pair of transactions, each exceeding the 64kB limit.
+my $in = '';
+my $out = '';
+
+my $timer = IPC::Run::timeout(180);
+
+my $h = $node_publisher->background_psql('postgres', \$in, \$out, $timer,
+ on_error_stop => 0);
+
+$in .= q{
+BEGIN;
+INSERT INTO test_tab SELECT i, md5(i::text) FROM generate_series(3, 5000) s(i);
+UPDATE test_tab SET b = md5(b) WHERE mod(a,2) = 0;
+DELETE FROM test_tab WHERE mod(a,3) = 0;
+};
+$h->pump_nb;
+
+$node_publisher->safe_psql(
+ 'postgres', q{
+BEGIN;
+INSERT INTO test_tab SELECT i, md5(i::text) FROM generate_series(5001, 9999) s(i);
+DELETE FROM test_tab WHERE a > 5000;
+COMMIT;
+});
+
+$in .= q{
+COMMIT;
+\q
+};
+$h->finish; # errors make the next test fail, so ignore them here
+
+$node_publisher->wait_for_catchup($appname1);
+$node_publisher->wait_for_catchup($appname2);
+$node_publisher->wait_for_catchup($appname3);
+
+# Verify data is replicated to the subscribers.
+my $result =
+ $node_subscriber1->safe_psql('postgres', "SELECT count(*), count(c), count(d = 999) FROM test_tab");
+is($result, qq(3332|3332|3332), 'check publisher data is replicated to the subscriber');
+
+$result =
+ $node_subscriber2->safe_psql('postgres', "SELECT count(*), count(c), count(d = 999) FROM test_tab");
+is($result, qq(3332|3332|3332), 'check publisher data is replicated to the subscriber');
+
+$result =
+ $node_subscriber3->safe_psql('postgres', "SELECT count(*), count(c), count(d = 999) FROM test_tab");
+is($result, qq(3332|3332|3332), 'check publisher data is replicated to the subscriber');
+
+# Test to verify replication statistics data is updated in
+# pg_stat_replication_slots statistics view.
+$result = $node_publisher->safe_psql('postgres',
+ "SELECT slot_name,
+ spill_txns > 0 AS spill_txns,
+ spill_count > 0 AS spill_count,
+ spill_bytes > 0 AS spill_bytes,
+ stream_txns > 0 AS stream_txns,
+ stream_count > 0 AS stream_count,
+ stream_bytes > 0 AS stream_bytes,
+ stats_reset
+ FROM pg_stat_replication_slots ORDER BY slot_name"
+);
+is($result, qq(tap_sub1|f|f|f|t|t|t|
+tap_sub2|t|t|t|f|f|f|
+tap_sub3|t|t|t|f|f|f|), 'check replication statistics are updated');
+
+# Test to drop one of the subscribers and verify replication statistics data is
+# fine after publisher is restarted.
+$node_subscriber3->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub3;");
+
+$node_publisher->stop;
+$node_publisher->start;
+
+# Verify statistics data present in pg_stat_replication_slots are sane after
+# publisher is restarted
+$result = $node_publisher->safe_psql('postgres',
+ "SELECT slot_name,
+ spill_txns > 0 AS spill_txns,
+ spill_count > 0 AS spill_count,
+ spill_bytes > 0 AS spill_bytes,
+ stream_txns > 0 AS stream_txns,
+ stream_count > 0 AS stream_count,
+ stream_bytes > 0 AS stream_bytes,
+ stats_reset
+ FROM pg_stat_replication_slots ORDER BY slot_name"
+);
+is($result, qq(tap_sub1|f|f|f|t|t|t|
+tap_sub2|t|t|t|f|f|f|), 'check replication statistics are updated');
+
+# shutdown
+$node_subscriber1->stop;
+$node_subscriber2->stop;
+$node_subscriber3->stop;
+$node_publisher->stop;
--
2.25.1
From 93c65c7e942e60c1b4f8363cb2fc521c49e47ee7 Mon Sep 17 00:00:00 2001
From: vignesh <vignes...@gmail.com>
Date: Thu, 1 Apr 2021 11:02:54 +0530
Subject: [PATCH v1 3/4] Add total txns and total txn bytes for 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.
---
doc/src/sgml/monitoring.sgml | 24 +++++++++++++++++++
src/backend/catalog/system_views.sql | 2 ++
src/backend/postmaster/pgstat.c | 9 ++++++-
src/backend/replication/logical/logical.c | 16 ++++++++-----
.../replication/logical/reorderbuffer.c | 5 ++++
src/backend/replication/slot.c | 2 +-
src/backend/utils/adt/pgstatfuncs.c | 8 ++++---
src/include/catalog/pg_proc.dat | 6 ++---
src/include/pgstat.h | 7 +++++-
src/include/replication/reorderbuffer.h | 4 ++++
src/test/regress/expected/rules.out | 4 +++-
11 files changed, 71 insertions(+), 16 deletions(-)
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index af540fb02f..d816c0525a 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -2689,6 +2689,30 @@ 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 in-progress transactions replicated to the decoding output
+ plugin. 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 in-progress transaction data replicated to the decoding
+ output plugin while decoding changes from WAL for this slot. This and other
+ counters for this slot can be used to gauge the network I/O which occurred
+ during logical decoding and allow tuning <literal>logical_decoding_work_mem</literal>.
+ </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 132fdef78c..b497fbed37 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -1775,7 +1775,8 @@ pgstat_report_tempfile(size_t filesize)
*/
void
pgstat_report_replslot(const char *slotname, int spilltxns, int spillcount,
- int spillbytes, int streamtxns, int streamcount, int streambytes)
+ int spillbytes, int streamtxns, int streamcount,
+ int streambytes, int totaltxns, int totalbytes)
{
PgStat_MsgReplSlot msg;
@@ -1791,6 +1792,8 @@ pgstat_report_replslot(const char *slotname, int spilltxns, int spillcount,
msg.m_stream_txns = streamtxns;
msg.m_stream_count = streamcount;
msg.m_stream_bytes = streambytes;
+ msg.m_total_txns = totaltxns;
+ msg.m_total_bytes = totalbytes;
pgstat_send(&msg, sizeof(PgStat_MsgReplSlot));
}
@@ -7089,6 +7092,8 @@ 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;
}
}
@@ -7360,6 +7365,8 @@ 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..3a178bfc3d 100644
--- a/src/backend/replication/logical/logical.c
+++ b/src/backend/replication/logical/logical.c
@@ -1765,28 +1765,32 @@ UpdateDecodingStats(LogicalDecodingContext *ctx)
ReorderBuffer *rb = ctx->reorder;
/*
- * 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);
+ (long long) rb->streamBytes,
+ (long long) rb->totalTxns,
+ (long long) rb->totalBytes);
pgstat_report_replslot(NameStr(ctx->slot->data.name),
rb->spillTxns, rb->spillCount, rb->spillBytes,
- rb->streamTxns, rb->streamCount, rb->streamBytes);
+ rb->streamTxns, rb->streamCount, rb->streamBytes,
+ rb->totalTxns, rb->totalBytes);
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..5bc0b05a0e 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 +661,8 @@ 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;
/* Update the total size in the top transaction. */
if (toptxn)
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index 75a087c2f9..7dba2298b4 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -328,7 +328,7 @@ 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_report_replslot(NameStr(slot->data.name), 0, 0, 0, 0, 0, 0, 0, 0);
/*
* 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 2ce8e1fd2d..c229b37abd 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;
@@ -2330,11 +2330,13 @@ pg_stat_get_replication_slots(PG_FUNCTION_ARGS)
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 69ffd0c3f4..8b2071c77b 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5296,9 +5296,9 @@
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 10784f947e..46445c3cee 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -515,6 +515,8 @@ 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;
@@ -879,6 +881,8 @@ typedef struct PgStat_ReplSlotStats
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;
@@ -1451,7 +1455,8 @@ 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, int spilltxns, int spillcount,
- int spillbytes, int streamtxns, int streamcount, int streambytes);
+ int spillbytes, int streamtxns, int streamcount,
+ int streambytes, int totaltxns, int totalbytes);
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 1924142ec8194dc661fd1f230e77bed6d3f9d201 Mon Sep 17 00:00:00 2001
From: vignesh <vignes...@gmail.com>
Date: Thu, 1 Apr 2021 20:50:10 +0530
Subject: [PATCH v1 4/4] 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 publisher 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.
---
src/backend/postmaster/pgstat.c | 24 +++++++++-
src/test/subscription/t/020_repl_stats.pl | 57 +++++++++++++++++++++--
2 files changed, 76 insertions(+), 5 deletions(-)
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index b497fbed37..c65f57889e 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -5699,6 +5699,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
*/
for (;;)
{
+ PgStat_ReplSlotStats replSlotStat;
switch (fgetc(fpin))
{
/*
@@ -5787,15 +5788,34 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
* slot follows.
*/
case 'R':
- if (fread(&replSlotStats[nReplSlotStats], 1, sizeof(PgStat_ReplSlotStats), fpin)
+ if (fread(&replSlotStat, 1, sizeof(PgStat_ReplSlotStats), fpin)
!= sizeof(PgStat_ReplSlotStats))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted statistics file \"%s\"",
statfile)));
- memset(&replSlotStats[nReplSlotStats], 0, sizeof(PgStat_ReplSlotStats));
goto done;
}
+
+ /*
+ * 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 publisher is
+ * re-started then the statistics process will not be aware of
+ * this, to avoid writing beyond the max_replication_slots
+ * these replication slot statistic information will be skipped.
+ */
+ if (max_replication_slots == nReplSlotStats)
+ {
+ ereport(pgStatRunningInCollector ? LOG : WARNING,
+ (errmsg("skipping \"%s\" replication slot's statistic as the statistic collector process does not have enough statistic slots",
+ replSlotStat.slotname)));
+ goto done;
+ }
+
+ memcpy(&replSlotStats[nReplSlotStats], &replSlotStat, sizeof(PgStat_ReplSlotStats));
nReplSlotStats++;
break;
diff --git a/src/test/subscription/t/020_repl_stats.pl b/src/test/subscription/t/020_repl_stats.pl
index 4be58d417a..b0674f2d41 100644
--- a/src/test/subscription/t/020_repl_stats.pl
+++ b/src/test/subscription/t/020_repl_stats.pl
@@ -2,9 +2,10 @@
# view for logical replication.
use strict;
use warnings;
+use File::Path qw(rmtree);
use PostgresNode;
use TestLib;
-use Test::More tests => 5;
+use Test::More tests => 7;
# Create publisher node.
my $node_publisher = get_new_node('publisher');
@@ -25,6 +26,10 @@ my $node_subscriber3 = get_new_node('subscriber3');
$node_subscriber3->init(allows_streaming => 'logical');
$node_subscriber3->start;
+my $node_subscriber4 = get_new_node('subscriber4');
+$node_subscriber4->init(allows_streaming => 'logical');
+$node_subscriber4->start;
+
# Create table on publisher.
$node_publisher->safe_psql('postgres',
"CREATE TABLE test_tab (a int primary key, b varchar)");
@@ -33,6 +38,7 @@ $node_publisher->safe_psql('postgres',
$node_subscriber1->safe_psql('postgres', "CREATE TABLE test_tab (a int primary key, b text, c timestamptz DEFAULT now(), d bigint DEFAULT 999)");
$node_subscriber2->safe_psql('postgres', "CREATE TABLE test_tab (a int primary key, b text, c timestamptz DEFAULT now(), d bigint DEFAULT 999)");
$node_subscriber3->safe_psql('postgres', "CREATE TABLE test_tab (a int primary key, b text, c timestamptz DEFAULT now(), d bigint DEFAULT 999)");
+$node_subscriber4->safe_psql('postgres', "CREATE TABLE test_tab (a int primary key, b text, c timestamptz DEFAULT now(), d bigint DEFAULT 999)");
# Setup logical replication.
my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
@@ -62,9 +68,18 @@ $node_subscriber3->safe_psql('postgres',
PUBLICATION tap_pub WITH (streaming = off)"
);
+my $appname4 = 'tap_sub4';
+$node_subscriber4->safe_psql('postgres',
+ "CREATE SUBSCRIPTION tap_sub4
+ CONNECTION '$publisher_connstr
+ application_name=$appname4'
+ PUBLICATION tap_pub WITH (streaming = off)"
+);
+
$node_publisher->wait_for_catchup($appname1);
$node_publisher->wait_for_catchup($appname2);
$node_publisher->wait_for_catchup($appname3);
+$node_publisher->wait_for_catchup($appname4);
# Interleave a pair of transactions, each exceeding the 64kB limit.
my $in = '';
@@ -100,6 +115,7 @@ $h->finish; # errors make the next test fail, so ignore them here
$node_publisher->wait_for_catchup($appname1);
$node_publisher->wait_for_catchup($appname2);
$node_publisher->wait_for_catchup($appname3);
+$node_publisher->wait_for_catchup($appname4);
# Verify data is replicated to the subscribers.
my $result =
@@ -114,6 +130,10 @@ $result =
$node_subscriber3->safe_psql('postgres', "SELECT count(*), count(c), count(d = 999) FROM test_tab");
is($result, qq(3332|3332|3332), 'check publisher data is replicated to the subscriber');
+$result =
+ $node_subscriber4->safe_psql('postgres', "SELECT count(*), count(c), count(d = 999) FROM test_tab");
+is($result, qq(3332|3332|3332), 'check publisher data is replicated to the subscriber');
+
# Test to verify replication statistics data is updated in
# pg_stat_replication_slots statistics view.
$result = $node_publisher->safe_psql('postgres',
@@ -129,13 +149,43 @@ $result = $node_publisher->safe_psql('postgres',
);
is($result, qq(tap_sub1|f|f|f|t|t|t|
tap_sub2|t|t|t|f|f|f|
-tap_sub3|t|t|t|f|f|f|), 'check replication statistics are updated');
+tap_sub3|t|t|t|f|f|f|
+tap_sub4|t|t|t|f|f|f|), 'check replication statistics are updated');
# Test to drop one of the subscribers and verify replication statistics data is
# fine after publisher is restarted.
-$node_subscriber3->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub3;");
+$node_subscriber4->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub4;");
+
+$node_publisher->stop;
+$node_publisher->start;
+
+# Verify statistics data present in pg_stat_replication_slots are sane after
+# publisher is restarted
+$result = $node_publisher->safe_psql('postgres',
+ "SELECT slot_name,
+ spill_txns > 0 AS spill_txns,
+ spill_count > 0 AS spill_count,
+ spill_bytes > 0 AS spill_bytes,
+ stream_txns > 0 AS stream_txns,
+ stream_count > 0 AS stream_count,
+ stream_bytes > 0 AS stream_bytes,
+ stats_reset
+ FROM pg_stat_replication_slots ORDER BY slot_name"
+);
+is($result, qq(tap_sub1|f|f|f|t|t|t|
+tap_sub2|t|t|t|f|f|f|
+tap_sub3|t|t|t|f|f|f|), '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 publisher is restarted.
$node_publisher->stop;
+my $publisher_data = $node_publisher->data_dir;
+my $subscriber3_replslotdir = "$publisher_data/pg_replslot/tap_sub3";
+
+rmtree($subscriber3_replslotdir);
+
+$node_publisher->append_conf('postgresql.conf', 'max_replication_slots = 2');
$node_publisher->start;
# Verify statistics data present in pg_stat_replication_slots are sane after
@@ -158,4 +208,5 @@ tap_sub2|t|t|t|f|f|f|), 'check replication statistics are updated');
$node_subscriber1->stop;
$node_subscriber2->stop;
$node_subscriber3->stop;
+$node_subscriber4->stop;
$node_publisher->stop;
--
2.25.1
