mongodb resource_error ai_generated partial

MongoServerError: OplogSlotNotAvailable: Cannot allocate oplog entry due to replication lag

ID: mongodb/oplog-slot-not-available

Also available as: JSON · Markdown · 中文
80%Fix Rate
85%Confidence
1Evidence
2024-03-15First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
MongoDB 6.0.5 active — — —
MongoDB 7.0.1 active — — —

Root Cause

Secondary replication lag caused the primary to exhaust oplog slots, preventing new writes.

generic

中文

从节点复制延迟导致主节点oplog槽位耗尽，无法处理新写入请求。

Official Documentation

https://www.mongodb.com/docs/manual/reference/errors/

Workarounds

  1. 75% success Temporarily reduce write load by throttling application writes or pausing batch jobs. Use db.setProfilingLevel(0) to disable profiling if enabled. 
    Temporarily reduce write load by throttling application writes or pausing batch jobs. Use db.setProfilingLevel(0) to disable profiling if enabled.
  2. 85% success Increase secondary's priority or add more secondaries to distribute replication load. Use rs.add('host:port') to add a new secondary. 
    Increase secondary's priority or add more secondaries to distribute replication load. Use rs.add('host:port') to add a new secondary.

中文步骤

  1. Temporarily reduce write load by throttling application writes or pausing batch jobs. Use db.setProfilingLevel(0) to disable profiling if enabled.
  2. Increase secondary's priority or add more secondaries to distribute replication load. Use rs.add('host:port') to add a new secondary.

Dead Ends

Common approaches that don't work:

  1. 60% fail

    Increasing oplog size doesn't fix the underlying replication delay; it only delays exhaustion.

  2. 80% fail

    Restarting the primary resets the oplog but doesn't resolve secondary lag; issue recurs quickly.