这是本节的多页打印视图。 .

Activity 等待

后台进程在主循环中休眠，等待新工作到来。

1: Activity: ArchiverMain
2: Activity: AutovacuumMain
3: Activity: BgwriterHibernate
4: Activity: BgwriterMain
5: Activity: CheckpointerMain
6: Activity: CheckpointerShutdown
7: Activity: IoWorkerMain
8: Activity: LogicalApplyMain
9: Activity: LogicalLauncherMain
10: Activity: LogicalParallelApplyMain
11: Activity: PgStatMain
12: Activity: RecoveryWalStream
13: Activity: ReplicationSlotsyncMain
14: Activity: ReplicationSlotsyncShutdown
15: Activity: SysloggerMain
16: Activity: WalReceiverMain
17: Activity: WalSenderMain
18: Activity: WalSummarizerWal
19: Activity: WalWriterMain

Activity 多数时候只是健康后台进程空闲时的声音。Archiver、checkpointer、WAL writer、autovacuum launcher、复制 worker 等进程在主循环中等待时会报告各自的名称。

按 backend type 解释

这些事件不应进入前台“等待会话比例”的分母。应把事件与 backend_type 对照，并询问该进程此刻是否本来就该有工作。

正常： 一个匹配的后台进程在文档说明的主循环中等待。
关注： 事件出现在错误的后端类型、进程缺失，或工作队列增长但它仍空闲。
紧急： 必需的后台进度停止——归档积压、不再产生检查点、复制不推进，或关闭无法完成。

值得先认出的事件

事件	预期进程
AutovacuumMain	调度周期之间的 autovacuum launcher
CheckpointerMain	等待工作的 checkpointer
WalWriterMain	WAL writer 主循环
ArchiverMain	等待完整 WAL 段的 archiver
WalReceiverMain	WAL receiver 主循环
RecoveryWalStream	startup 进程等待流式 WAL
IoWorkerMain	PG18 异步 I/O worker 等待工作

常见误读

Activity 在所有后端中占比很高，可能只说明集群很空闲。
空闲的 checkpointer 不表示检查点被禁用。
正常的等待名称并不能证明进度正常；还要检查队列、积压与时间戳。
缺少本应存在的后台进程，通常比看到它的 Activity 等待更重要。

1 - Activity: ArchiverMain

在 archiver 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件ArchiverMain 版本PG 13-18 证据2 个源码位置

官方描述译文

在 archiver 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
✓	✓	✓	✓	✓	✓

触发机制

WAIT_EVENT_ARCHIVER_MAIN 位于 src/backend/postmaster/pgarch.c:362，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:54。探针覆盖的操作是：在 archiver 进程的主循环中等待。ArchiverMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'ArchiverMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'ArchiverMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/postmaster/pgarch.c:362 — WAIT_EVENT_ARCHIVER_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:54 — ARCHIVER_MAIN

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

2 - Activity: AutovacuumMain

在 autovacuum launcher 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件AutovacuumMain 版本PG 17-18 证据4 个源码位置

官方描述译文

在 autovacuum launcher 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
—	—	—	—	✓	✓

历史名称：Activity/AutoVacuumMain (PG 13-16)

触发机制

WAIT_EVENT_AUTOVACUUM_MAIN 位于 src/backend/postmaster/autovacuum.c:667，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event.c:216。探针覆盖的操作是：在 autovacuum launcher 进程的主循环中等待。AutovacuumMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'AutovacuumMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'AutovacuumMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 16.15 · src/backend/postmaster/autovacuum.c:667 — WAIT_EVENT_AUTOVACUUM_MAIN
PostgreSQL 16.15 · src/backend/utils/activity/wait_event.c:216 — AutoVacuumMain
PostgreSQL 18.6 · src/backend/postmaster/autovacuum.c:595 — WAIT_EVENT_AUTOVACUUM_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:55 — AUTOVACUUM_MAIN

GUC: [guc:autovacuum_naptime]
指标: [metric:waiting_sessions] · [metric:wait_event_share] · [metric:oldest_transaction_age]

3 - Activity: BgwriterHibernate

在后台写入器进程休眠时等待。

PostgreSQL 等待事件档案

类别Activity 事件BgwriterHibernate 版本PG 17-18 证据4 个源码位置

官方描述译文

在后台写入器进程休眠时等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
—	—	—	—	✓	✓

历史名称：Activity/BgWriterHibernate (PG 13-16)

触发机制

WAIT_EVENT_BGWRITER_HIBERNATE 位于 src/backend/postmaster/bgwriter.c:339，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event.c:219。探针覆盖的操作是：在后台写入器进程休眠时等待。BgwriterHibernate 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'BgwriterHibernate'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'BgwriterHibernate'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 16.15 · src/backend/postmaster/bgwriter.c:339 — WAIT_EVENT_BGWRITER_HIBERNATE
PostgreSQL 16.15 · src/backend/utils/activity/wait_event.c:219 — BgWriterHibernate
PostgreSQL 18.6 · src/backend/postmaster/bgwriter.c:337 — WAIT_EVENT_BGWRITER_HIBERNATE
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:56 — BGWRITER_HIBERNATE

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

4 - Activity: BgwriterMain

在后台写入器进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件BgwriterMain 版本PG 17-18 证据4 个源码位置

官方描述译文

在后台写入器进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
—	—	—	—	✓	✓

历史名称：Activity/BgWriterMain (PG 13-16)

触发机制

WAIT_EVENT_BGWRITER_MAIN 位于 src/backend/postmaster/bgwriter.c:311，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event.c:222。探针覆盖的操作是：在后台写入器进程的主循环中等待。BgwriterMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'BgwriterMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'BgwriterMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 16.15 · src/backend/postmaster/bgwriter.c:311 — WAIT_EVENT_BGWRITER_MAIN
PostgreSQL 16.15 · src/backend/utils/activity/wait_event.c:222 — BgWriterMain
PostgreSQL 18.6 · src/backend/postmaster/bgwriter.c:309 — WAIT_EVENT_BGWRITER_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:57 — BGWRITER_MAIN

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

5 - Activity: CheckpointerMain

在 checkpointer 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件CheckpointerMain 版本PG 13-18 证据2 个源码位置

官方描述译文

在 checkpointer 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
✓	✓	✓	✓	✓	✓

触发机制

WAIT_EVENT_CHECKPOINTER_MAIN 位于 src/backend/postmaster/checkpointer.c:583，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:58。探针覆盖的操作是：在 checkpointer 进程的主循环中等待。CheckpointerMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'CheckpointerMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'CheckpointerMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/postmaster/checkpointer.c:583 — WAIT_EVENT_CHECKPOINTER_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:58 — CHECKPOINTER_MAIN

GUC: [guc:checkpoint_timeout] · [guc:max_wal_size]
指标: [metric:waiting_sessions] · [metric:wait_event_share] · [metric:checkpoint_time]

6 - Activity: CheckpointerShutdown

等待 checkpointer 进程终止。

PostgreSQL 等待事件档案

类别Activity 事件CheckpointerShutdown 版本PG 18 证据2 个源码位置

官方描述译文

等待 checkpointer 进程终止。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
—	—	—	—	—	✓

触发机制

WAIT_EVENT_CHECKPOINTER_SHUTDOWN 位于 src/backend/postmaster/checkpointer.c:631，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:59。探针覆盖的操作是：等待 checkpointer 进程终止。CheckpointerShutdown 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'CheckpointerShutdown'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'CheckpointerShutdown'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/postmaster/checkpointer.c:631 — WAIT_EVENT_CHECKPOINTER_SHUTDOWN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:59 — CHECKPOINTER_SHUTDOWN

GUC: [guc:checkpoint_timeout] · [guc:max_wal_size]
指标: [metric:waiting_sessions] · [metric:wait_event_share] · [metric:checkpoint_time]

7 - Activity: IoWorkerMain

在 I/O worker 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件IoWorkerMain 版本PG 18 证据2 个源码位置

官方描述译文

在 I/O worker 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
—	—	—	—	—	✓

触发机制

WAIT_EVENT_IO_WORKER_MAIN 位于 src/backend/storage/aio/method_worker.c:573，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:60。探针覆盖的操作是：在 I/O worker 进程的主循环中等待。IoWorkerMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'IoWorkerMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'IoWorkerMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/storage/aio/method_worker.c:573 — WAIT_EVENT_IO_WORKER_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:60 — IO_WORKER_MAIN

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

8 - Activity: LogicalApplyMain

在逻辑复制 apply 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件LogicalApplyMain 版本PG 13-18 证据2 个源码位置

官方描述译文

在逻辑复制 apply 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
✓	✓	✓	✓	✓	✓

触发机制

WAIT_EVENT_LOGICAL_APPLY_MAIN 位于 src/backend/replication/logical/worker.c:3766，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:61。探针覆盖的操作是：在逻辑复制 apply 进程的主循环中等待。LogicalApplyMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'LogicalApplyMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'LogicalApplyMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/replication/logical/worker.c:3766 — WAIT_EVENT_LOGICAL_APPLY_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:61 — LOGICAL_APPLY_MAIN

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

9 - Activity: LogicalLauncherMain

在逻辑复制 launcher 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件LogicalLauncherMain 版本PG 13-18 证据2 个源码位置

官方描述译文

在逻辑复制 launcher 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
✓	✓	✓	✓	✓	✓

触发机制

WAIT_EVENT_LOGICAL_LAUNCHER_MAIN 位于 src/backend/replication/logical/launcher.c:1242，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:62。探针覆盖的操作是：在逻辑复制 launcher 进程的主循环中等待。LogicalLauncherMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'LogicalLauncherMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'LogicalLauncherMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/replication/logical/launcher.c:1242 — WAIT_EVENT_LOGICAL_LAUNCHER_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:62 — LOGICAL_LAUNCHER_MAIN

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

10 - Activity: LogicalParallelApplyMain

在逻辑复制并行 apply 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件LogicalParallelApplyMain 版本PG 16-18 证据2 个源码位置

官方描述译文

在逻辑复制并行 apply 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
—	—	—	✓	✓	✓

触发机制

WAIT_EVENT_LOGICAL_PARALLEL_APPLY_MAIN 位于 src/backend/replication/logical/applyparallelworker.c:810，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:63。探针覆盖的操作是：在逻辑复制并行 apply 进程的主循环中等待。LogicalParallelApplyMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'LogicalParallelApplyMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'LogicalParallelApplyMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/replication/logical/applyparallelworker.c:810 — WAIT_EVENT_LOGICAL_PARALLEL_APPLY_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:63 — LOGICAL_PARALLEL_APPLY_MAIN

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

11 - Activity: PgStatMain

在统计收集器进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件PgStatMain 版本PG 13-14 证据2 个源码位置

官方描述译文

在统计收集器进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
✓	✓	—	—	—	—

触发机制

WAIT_EVENT_PGSTAT_MAIN 位于 src/backend/postmaster/pgstat.c:3425，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event.c:234。探针覆盖的操作是：在统计收集器进程的主循环中等待。PgStatMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'PgStatMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'PgStatMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 14.24 · src/backend/postmaster/pgstat.c:3425 — WAIT_EVENT_PGSTAT_MAIN
PostgreSQL 14.24 · src/backend/utils/activity/wait_event.c:234 — PgStatMain

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

12 - Activity: RecoveryWalStream

流式恢复期间，在 startup 进程的主循环中等待 WAL 到达。

PostgreSQL 等待事件档案

类别Activity 事件RecoveryWalStream 版本PG 13-18 证据2 个源码位置

官方描述译文

流式恢复期间，在 startup 进程的主循环中等待 WAL 到达。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
✓	✓	✓	✓	✓	✓

触发机制

WAIT_EVENT_RECOVERY_WAL_STREAM 位于 src/backend/access/transam/xlogrecovery.c:4038，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:64。探针覆盖的操作是：流式恢复期间，在 startup 进程的主循环中等待 WAL 到达。RecoveryWalStream 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'RecoveryWalStream'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'RecoveryWalStream'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/access/transam/xlogrecovery.c:4038 — WAIT_EVENT_RECOVERY_WAL_STREAM
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:64 — RECOVERY_WAL_STREAM

GUC: [guc:wal_buffers] · [guc:synchronous_commit]
指标: [metric:waiting_sessions] · [metric:wait_event_share] · [metric:wal_bytes] · [metric:wal_write_time]

13 - Activity: ReplicationSlotsyncMain

在复制槽同步 worker 的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件ReplicationSlotsyncMain 版本PG 17-18 证据2 个源码位置

官方描述译文

在复制槽同步 worker 的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
—	—	—	—	✓	✓

触发机制

WAIT_EVENT_REPLICATION_SLOTSYNC_MAIN 位于 src/backend/replication/logical/slotsync.c:1369，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:65。探针覆盖的操作是：在复制槽同步 worker 的主循环中等待。ReplicationSlotsyncMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'ReplicationSlotsyncMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'ReplicationSlotsyncMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/replication/logical/slotsync.c:1369 — WAIT_EVENT_REPLICATION_SLOTSYNC_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:65 — REPLICATION_SLOTSYNC_MAIN

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

14 - Activity: ReplicationSlotsyncShutdown

等待复制槽同步 worker 停止运行。

PostgreSQL 等待事件档案

类别Activity 事件ReplicationSlotsyncShutdown 版本PG 17-18 证据2 个源码位置

官方描述译文

等待复制槽同步 worker 停止运行。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
—	—	—	—	✓	✓

触发机制

WAIT_EVENT_REPLICATION_SLOTSYNC_SHUTDOWN 位于 src/backend/replication/logical/slotsync.c:1732，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:66。探针覆盖的操作是：等待复制槽同步 worker 停止运行。ReplicationSlotsyncShutdown 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'ReplicationSlotsyncShutdown'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'ReplicationSlotsyncShutdown'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/replication/logical/slotsync.c:1732 — WAIT_EVENT_REPLICATION_SLOTSYNC_SHUTDOWN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:66 — REPLICATION_SLOTSYNC_SHUTDOWN

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

15 - Activity: SysloggerMain

在 syslogger 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件SysloggerMain 版本PG 17-18 证据4 个源码位置

官方描述译文

在 syslogger 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
—	—	—	—	✓	✓

历史名称：Activity/SysLoggerMain (PG 13-16)

触发机制

WAIT_EVENT_SYSLOGGER_MAIN 位于 src/backend/postmaster/syslogger.c:487，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event.c:240。探针覆盖的操作是：在 syslogger 进程的主循环中等待。SysloggerMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'SysloggerMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'SysloggerMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 16.15 · src/backend/postmaster/syslogger.c:487 — WAIT_EVENT_SYSLOGGER_MAIN
PostgreSQL 16.15 · src/backend/utils/activity/wait_event.c:240 — SysLoggerMain
PostgreSQL 18.6 · src/backend/postmaster/syslogger.c:513 — WAIT_EVENT_SYSLOGGER_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:67 — SYSLOGGER_MAIN

GUC: 无直接关联项。
指标: [metric:waiting_sessions] · [metric:wait_event_share]

16 - Activity: WalReceiverMain

在 WAL receiver 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件WalReceiverMain 版本PG 13-18 证据2 个源码位置

官方描述译文

在 WAL receiver 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
✓	✓	✓	✓	✓	✓

触发机制

WAIT_EVENT_WAL_RECEIVER_MAIN 位于 src/backend/replication/walreceiver.c:600，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:68。探针覆盖的操作是：在 WAL receiver 进程的主循环中等待。WalReceiverMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'WalReceiverMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'WalReceiverMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/replication/walreceiver.c:600 — WAIT_EVENT_WAL_RECEIVER_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:68 — WAL_RECEIVER_MAIN

GUC: [guc:wal_buffers] · [guc:synchronous_commit]
指标: [metric:waiting_sessions] · [metric:wait_event_share] · [metric:wal_bytes] · [metric:wal_write_time]

17 - Activity: WalSenderMain

在 WAL sender 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件WalSenderMain 版本PG 13-18 证据2 个源码位置

官方描述译文

在 WAL sender 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
✓	✓	✓	✓	✓	✓

触发机制

WAIT_EVENT_WAL_SENDER_MAIN 位于 src/backend/replication/walsender.c:2963，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:69。探针覆盖的操作是：在 WAL sender 进程的主循环中等待。WalSenderMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'WalSenderMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'WalSenderMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/replication/walsender.c:2963 — WAIT_EVENT_WAL_SENDER_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:69 — WAL_SENDER_MAIN

GUC: [guc:wal_buffers] · [guc:synchronous_commit]
指标: [metric:waiting_sessions] · [metric:wait_event_share] · [metric:wal_bytes] · [metric:wal_write_time]

18 - Activity: WalSummarizerWal

在 WAL summarizer 中等待生成更多 WAL。

PostgreSQL 等待事件档案

类别Activity 事件WalSummarizerWal 版本PG 17-18 证据2 个源码位置

官方描述译文

在 WAL summarizer 中等待生成更多 WAL。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
—	—	—	—	✓	✓

触发机制

WAIT_EVENT_WAL_SUMMARIZER_WAL 位于 src/backend/postmaster/walsummarizer.c:1798，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:70。探针覆盖的操作是：在 WAL summarizer 中等待生成更多 WAL。WalSummarizerWal 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'WalSummarizerWal'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'WalSummarizerWal'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/postmaster/walsummarizer.c:1798 — WAIT_EVENT_WAL_SUMMARIZER_WAL
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:70 — WAL_SUMMARIZER_WAL

GUC: [guc:wal_buffers] · [guc:synchronous_commit]
指标: [metric:waiting_sessions] · [metric:wait_event_share] · [metric:wal_bytes] · [metric:wal_write_time]

19 - Activity: WalWriterMain

在 WAL writer 进程的主循环中等待。

PostgreSQL 等待事件档案

类别Activity 事件WalWriterMain 版本PG 13-18 证据2 个源码位置

官方描述译文

在 WAL writer 进程的主循环中等待。

PG 13	PG 14	PG 15	PG 16	PG 17	PG 18
✓	✓	✓	✓	✓	✓

触发机制

WAIT_EVENT_WAL_WRITER_MAIN 位于 src/backend/postmaster/walwriter.c:271，是经 grep 核验的报告路径。公共身份/资源映射位于 src/backend/utils/activity/wait_event_names.txt:71。探针覆盖的操作是：在 WAL writer 进程的主循环中等待。WalWriterMain 后台路径在主循环暂时无事可做、进入 latch wait 前报告此事件；信号、计时器或新工作会唤醒进程并进入下一轮循环。

正常还是麻烦？

正常: 对匹配的后台进程而言，这通常是预期空闲。
需要调查: 只有工作队列、关闭或故障切换时限没有推进但进程一直停在这里，或事件出现在不匹配的后端类型上时，才需要调查。

诊断 SQL

SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
  AND wait_event = 'WalWriterMain'
ORDER BY query_age DESC NULLS LAST;

SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Activity'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;

SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Activity'
  AND a.wait_event = 'WalWriterMain'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

先与 backend_type 对照。
检查该进程专属的积压与最后进展时间。
修复缺失的工作信号或停滞的上游阶段，不要终止正常空闲的 worker。

源码证据

PostgreSQL 18.6 · src/backend/postmaster/walwriter.c:271 — WAIT_EVENT_WAL_WRITER_MAIN
PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:71 — WAL_WRITER_MAIN

GUC: [guc:wal_buffers] · [guc:synchronous_commit]
指标: [metric:waiting_sessions] · [metric:wait_event_share] · [metric:wal_bytes] · [metric:wal_write_time]

Activity 等待

按 backend type 解释

值得先认出的事件

常见误读

1 - Activity: ArchiverMain

官方描述译文

触发机制

正常还是麻烦？

诊断 SQL

处置建议

源码证据

关联控制项与信号

2 - Activity: AutovacuumMain

官方描述译文

触发机制

正常还是麻烦？

诊断 SQL

处置建议

源码证据

关联控制项与信号

3 - Activity: BgwriterHibernate

官方描述译文

触发机制

正常还是麻烦？

诊断 SQL

处置建议

源码证据

关联控制项与信号

4 - Activity: BgwriterMain

官方描述译文

触发机制

正常还是麻烦？

诊断 SQL

处置建议

源码证据

关联控制项与信号

5 - Activity: CheckpointerMain

官方描述译文

触发机制

正常还是麻烦？

诊断 SQL

处置建议

源码证据

关联控制项与信号

6 - Activity: CheckpointerShutdown

官方描述译文

触发机制

正常还是麻烦？

诊断 SQL

处置建议

源码证据

关联控制项与信号

7 - Activity: IoWorkerMain

官方描述译文

触发机制

正常还是麻烦？

诊断 SQL

处置建议

源码证据

关联控制项与信号

8 - Activity: LogicalApplyMain

官方描述译文

触发机制

正常还是麻烦？

诊断 SQL

处置建议

源码证据

关联控制项与信号

9 - Activity: LogicalLauncherMain

官方描述译文

触发机制

正常还是麻烦？

诊断 SQL

处置建议

源码证据

关联控制项与信号

10 - Activity: LogicalParallelApplyMain

官方描述译文

触发机制

正常还是麻烦？