From b1a9bad9e744857291c7d5516080527da8219854 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Thu, 7 Jan 2016 16:21:19 -0300 Subject: [PATCH] pgstat: add WAL receiver status view & SRF This new view provides insight into the state of a running WAL receiver in a HOT standby node. The information returned includes the PID of the WAL receiver process, its status (stopped, starting, streaming, etc), start LSN and TLI, last received LSN and TLI, timestamp of last message send and receipt, latest end-of-WAL LSN and time, and the name of the slot (if any). Access to the detailed data is only granted to superusers; others only get the PID. Author: Michael Paquier Reviewer: Haribabu Kommi --- doc/src/sgml/monitoring.sgml | 91 +++++++++++++++ src/backend/catalog/system_views.sql | 16 +++ src/backend/replication/walreceiver.c | 154 ++++++++++++++++++++++++++ src/include/catalog/catversion.h | 2 +- src/include/catalog/pg_proc.h | 2 + src/include/replication/walreceiver.h | 2 + src/test/regress/expected/rules.out | 13 +++ 7 files changed, 279 insertions(+), 1 deletion(-) diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index c503636a88..85459d04b4 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -300,6 +300,14 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser + + pg_stat_wal_receiverpg_stat_wal_receiver + Only one row, showing statistics about the WAL receiver from + that receiver's connected server. + See for details. + + + pg_stat_sslpg_stat_ssl One row per connection (regular and replication), showing information about @@ -833,6 +841,89 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser listed; no information is available about downstream standby servers. + + <structname>pg_stat_wal_receiver</structname> View + + + + Column + Type + Description + + + + + + pid + integer + Process ID of the WAL receiver process + + + status + text + Activity status of the WAL receiver process + + + receive_start_lsn + pg_lsn + First transaction log position used when WAL receiver is + started + + + receive_start_tli + integer + First timeline number used when WAL receiver is started + + + received_lsn + pg_lsn + Last transaction log position already received and flushed to + disk, the initial value of this field being the first log position used + when WAL receiver is started + + + received_tli + integer + Timeline number of last transaction log position received and + flushed to disk, the initial value of this field being the timeline + number of the first log position used when WAL receiver is started + + + + last_msg_send_time + timestamp with time zone + Send time of last message received from origin WAL sender + + + last_msg_receipt_time + timestamp with time zone + Receipt time of last message received from origin WAL sender + + + latest_end_lsn + pg_lsn + Last transaction log position reported to origin WAL sender + + + latest_end_time + timestamp with time zone + Time of last transaction log position reported to origin WAL sender + + + slot_name + text + Replication slot name used by this WAL receiver + + + +
+ + + The pg_stat_wal_receiver view will contain only + one row, showing statistics about the WAL receiver from that receiver's + connected server. + + <structname>pg_stat_ssl</structname> View diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 2052afdc8d..506a884e33 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -662,6 +662,22 @@ CREATE VIEW pg_stat_replication AS WHERE S.usesysid = U.oid AND S.pid = W.pid; +CREATE VIEW pg_stat_wal_receiver AS + SELECT + s.pid, + s.status, + s.receive_start_lsn, + s.receive_start_tli, + s.received_lsn, + s.received_tli, + s.last_msg_send_time, + s.last_msg_receipt_time, + s.latest_end_lsn, + s.latest_end_time, + s.slot_name + FROM pg_stat_get_wal_receiver() s + WHERE s.pid IS NOT NULL; + CREATE VIEW pg_stat_ssl AS SELECT S.pid, diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c index 81f152940d..7b36e02faa 100644 --- a/src/backend/replication/walreceiver.c +++ b/src/backend/replication/walreceiver.c @@ -46,9 +46,12 @@ #include #include +#include "access/htup_details.h" #include "access/timeline.h" #include "access/transam.h" #include "access/xlog_internal.h" +#include "catalog/pg_type.h" +#include "funcapi.h" #include "libpq/pqformat.h" #include "libpq/pqsignal.h" #include "miscadmin.h" @@ -57,7 +60,9 @@ #include "storage/ipc.h" #include "storage/pmsignal.h" #include "storage/procarray.h" +#include "utils/builtins.h" #include "utils/guc.h" +#include "utils/pg_lsn.h" #include "utils/ps_status.h" #include "utils/resowner.h" #include "utils/timestamp.h" @@ -1215,3 +1220,152 @@ ProcessWalSndrMessage(XLogRecPtr walEnd, TimestampTz sendTime) pfree(receipttime); } } + +/* + * Return a string constant representing the state. This is used + * in system functions and views, and should *not* be translated. + */ +static const char * +WalRcvGetStateString(WalRcvState state) +{ + switch (state) + { + case WALRCV_STOPPED: + return "stopped"; + case WALRCV_STARTING: + return "starting"; + case WALRCV_STREAMING: + return "streaming"; + case WALRCV_WAITING: + return "waiting"; + case WALRCV_RESTARTING: + return "restarting"; + case WALRCV_STOPPING: + return "stopping"; + } + return "UNKNOWN"; +} + +/* + * Returns activity of WAL receiver, including pid, state and xlog locations + * received from the WAL sender of another server. + */ +Datum +pg_stat_get_wal_receiver(PG_FUNCTION_ARGS) +{ +#define PG_STAT_GET_WAL_RECEIVER_COLS 11 + TupleDesc tupdesc; + Datum values[PG_STAT_GET_WAL_RECEIVER_COLS]; + bool nulls[PG_STAT_GET_WAL_RECEIVER_COLS]; + WalRcvData *walrcv = WalRcv; + WalRcvState state; + XLogRecPtr receive_start_lsn; + TimeLineID receive_start_tli; + XLogRecPtr received_lsn; + TimeLineID received_tli; + TimestampTz last_send_time; + TimestampTz last_receipt_time; + XLogRecPtr latest_end_lsn; + TimestampTz latest_end_time; + char *slotname; + + /* No WAL receiver, just return a tuple with NULL values */ + if (walrcv->pid == 0) + PG_RETURN_NULL(); + + /* Initialise values and NULL flags arrays */ + MemSet(values, 0, sizeof(values)); + MemSet(nulls, 0, sizeof(nulls)); + + /* Initialise attributes information in the tuple descriptor */ + tupdesc = CreateTemplateTupleDesc(PG_STAT_GET_WAL_RECEIVER_COLS, false); + TupleDescInitEntry(tupdesc, (AttrNumber) 1, "pid", + INT4OID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 2, "status", + TEXTOID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 3, "receive_start_lsn", + LSNOID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 4, "receive_start_tli", + INT4OID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 5, "received_lsn", + LSNOID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 6, "received_tli", + INT4OID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 7, "last_msg_send_time", + TIMESTAMPTZOID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 8, "last_msg_receipt_time", + TIMESTAMPTZOID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 9, "latest_end_lsn", + LSNOID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 10, "latest_end_time", + TIMESTAMPTZOID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 11, "slot_name", + TEXTOID, -1, 0); + + BlessTupleDesc(tupdesc); + + /* Take a lock to ensure value consistency */ + SpinLockAcquire(&walrcv->mutex); + state = walrcv->walRcvState; + receive_start_lsn = walrcv->receiveStart; + receive_start_tli = walrcv->receiveStartTLI; + received_lsn = walrcv->receivedUpto; + received_tli = walrcv->receivedTLI; + last_send_time = walrcv->lastMsgSendTime; + last_receipt_time = walrcv->lastMsgReceiptTime; + latest_end_lsn = walrcv->latestWalEnd; + latest_end_time = walrcv->latestWalEndTime; + slotname = pstrdup(walrcv->slotname); + SpinLockRelease(&walrcv->mutex); + + /* Fetch values */ + values[0] = Int32GetDatum(walrcv->pid); + + if (!superuser()) + { + /* + * Only superusers can see details. Other users only get the pid + * value to know whether it is a WAL receiver, but no details. + */ + MemSet(&nulls[1], true, PG_STAT_GET_WAL_RECEIVER_COLS - 1); + } + else + { + values[1] = CStringGetTextDatum(WalRcvGetStateString(state)); + + if (XLogRecPtrIsInvalid(receive_start_lsn)) + nulls[2] = true; + else + values[2] = LSNGetDatum(receive_start_lsn); + values[3] = Int32GetDatum(receive_start_tli); + if (XLogRecPtrIsInvalid(received_lsn)) + nulls[4] = true; + else + values[4] = LSNGetDatum(received_lsn); + values[5] = Int32GetDatum(received_tli); + if (last_send_time == 0) + nulls[6] = true; + else + values[6] = TimestampTzGetDatum(last_send_time); + if (last_receipt_time == 0) + nulls[7] = true; + else + values[7] = TimestampTzGetDatum(last_receipt_time); + if (XLogRecPtrIsInvalid(latest_end_lsn)) + nulls[8] = true; + else + values[8] = LSNGetDatum(latest_end_lsn); + if (latest_end_time == 0) + nulls[9] = true; + else + values[9] = TimestampTzGetDatum(latest_end_time); + if (*slotname == '\0') + nulls[10] = true; + else + values[10] = CStringGetTextDatum(slotname); + } + + /* Returns the record as Datum */ + PG_RETURN_DATUM(HeapTupleGetDatum( + heap_form_tuple(tupdesc, values, nulls))); +} diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h index 31a132ea98..eaa7a51891 100644 --- a/src/include/catalog/catversion.h +++ b/src/include/catalog/catversion.h @@ -53,6 +53,6 @@ */ /* yyyymmddN */ -#define CATALOG_VERSION_NO 201601052 +#define CATALOG_VERSION_NO 201601071 #endif diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h index 9250545d3b..86b09a15ea 100644 --- a/src/include/catalog/pg_proc.h +++ b/src/include/catalog/pg_proc.h @@ -2787,6 +2787,8 @@ DATA(insert OID = 2022 ( pg_stat_get_activity PGNSP PGUID 12 1 100 0 0 f f f DESCR("statistics: information about currently active backends"); DATA(insert OID = 3099 ( pg_stat_get_wal_senders PGNSP PGUID 12 1 10 0 0 f f f f f t s r 0 0 2249 "" "{23,25,3220,3220,3220,3220,23,25}" "{o,o,o,o,o,o,o,o}" "{pid,state,sent_location,write_location,flush_location,replay_location,sync_priority,sync_state}" _null_ _null_ pg_stat_get_wal_senders _null_ _null_ _null_ )); DESCR("statistics: information about currently active replication"); +DATA(insert OID = 3317 ( pg_stat_get_wal_receiver PGNSP PGUID 12 1 0 0 0 f f f f f f s r 0 0 2249 "" "{23,25,3220,23,3220,23,1184,1184,3220,1184,25}" "{o,o,o,o,o,o,o,o,o,o,o}" "{pid,status,receive_start_lsn,receive_start_tli,received_lsn,received_tli,last_msg_send_time,last_msg_receipt_time,latest_end_lsn,latest_end_time,slot_name}" _null_ _null_ pg_stat_get_wal_receiver _null_ _null_ _null_ )); +DESCR("statistics: information about WAL receiver"); DATA(insert OID = 2026 ( pg_backend_pid PGNSP PGUID 12 1 0 0 0 f f f f t f s r 0 0 23 "" _null_ _null_ _null_ _null_ _null_ pg_backend_pid _null_ _null_ _null_ )); DESCR("statistics: current backend PID"); DATA(insert OID = 1937 ( pg_stat_get_backend_pid PGNSP PGUID 12 1 0 0 0 f f f f t f s r 1 0 23 "23" _null_ _null_ _null_ _null_ _null_ pg_stat_get_backend_pid _null_ _null_ _null_ )); diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h index db40d9d760..6eacb095d1 100644 --- a/src/include/replication/walreceiver.h +++ b/src/include/replication/walreceiver.h @@ -14,6 +14,7 @@ #include "access/xlog.h" #include "access/xlogdefs.h" +#include "fmgr.h" #include "storage/latch.h" #include "storage/spin.h" #include "pgtime.h" @@ -148,6 +149,7 @@ extern PGDLLIMPORT walrcv_disconnect_type walrcv_disconnect; /* prototypes for functions in walreceiver.c */ extern void WalReceiverMain(void) pg_attribute_noreturn(); +extern Datum pg_stat_get_wal_receiver(PG_FUNCTION_ARGS); /* prototypes for functions in walreceiverfuncs.c */ extern Size WalRcvShmemSize(void); diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 80374e4d50..28b061f9d5 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1848,6 +1848,19 @@ pg_stat_user_tables| SELECT pg_stat_all_tables.relid, pg_stat_all_tables.autoanalyze_count FROM pg_stat_all_tables WHERE ((pg_stat_all_tables.schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (pg_stat_all_tables.schemaname !~ '^pg_toast'::text)); +pg_stat_wal_receiver| SELECT s.pid, + s.status, + s.receive_start_lsn, + s.receive_start_tli, + s.received_lsn, + s.received_tli, + s.last_msg_send_time, + s.last_msg_receipt_time, + s.latest_end_lsn, + s.latest_end_time, + s.slot_name + FROM pg_stat_get_wal_receiver() s(pid, status, receive_start_lsn, receive_start_tli, received_lsn, received_tli, last_msg_send_time, last_msg_receipt_time, latest_end_lsn, latest_end_time, slot_name) + WHERE (s.pid IS NOT NULL); pg_stat_xact_all_tables| SELECT c.oid AS relid, n.nspname AS schemaname, c.relname, -- 2.40.0