跳转到主要内容

Timeout: WalSummarizerError

WAL summarizer 出错后等待。
PostgreSQL 等待事件档案
类别Timeout 事件WalSummarizerError 版本PG 17-18 证据2 个源码位置

官方描述译文

WAL summarizer 出错后等待。

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

触发机制

WAIT_EVENT_WAL_SUMMARIZER_ERROR 位于 src/backend/postmaster/walsummarizer.c:337,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:184。探针覆盖的操作是:WAL summarizer 出错后等待。WalSummarizerError 路径有意等待计时器、重试间隔、节流或安全退避;latch 超时后才重新评估工作。

正常还是麻烦?

  • 正常: 当配置策略是有意的,而且有效工作按预期速率推进时,这项等待正常。
  • 需要调查: 策略导致维护、恢复、备份或延迟目标无法达成,或者 spin delay 持续时,应当调查。

诊断 SQL

正在等待 Timeout/WalSummarizerError 的会话
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 = 'Timeout'
  AND wait_event = 'WalSummarizerError'
ORDER BY query_age DESC NULLS LAST;
当前 Timeout 等待分布
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 = 'Timeout'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;
这些会话的锁与关系上下文
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 = 'Timeout'
  AND a.wait_event = 'WalSummarizerError'
ORDER BY a.pid, l.granted, l.locktype, l.mode;

处置建议

  1. 确认拥有该计时器的 GUC 或函数。
  2. 比较有效工作量与延迟时间。
  3. 先检查它原本要控制的 CPU、I/O 与持久性压力,再调整策略。

源码证据