mongodb resource_error ai_generated true

MongoServerError: connection pool exhausted: maxPoolSize of 100 reached

ID: mongodb/atlas-connection-pool-exhausted

Also available as: JSON · Markdown · 中文
85%Fix Rate
86%Confidence
1Evidence
2023-09-12First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
mongodb 7.0 active — — —
mongodb 6.0 active — — —
mongodb 5.0 active — — —
mongodb 4.4 active — — —
mongodb-atlas 1.0 active — — —

Root Cause

The application opened more connections than the maxPoolSize limit, often due to unclosed cursors or connection leaks.

generic

中文

应用程序打开的连接数超过了maxPoolSize限制，通常是由于未关闭的游标或连接泄漏。

Official Documentation

https://www.mongodb.com/docs/manual/reference/connection-string-options/#maxPoolSize

Workarounds

  1. 90% success Ensure all cursors are closed in a try-finally block: try { cursor = collection.find(); ... } finally { cursor.close(); } 
    Ensure all cursors are closed in a try-finally block: try { cursor = collection.find(); ... } finally { cursor.close(); }
  2. 75% success Set a lower maxPoolSize and monitor connections: MongoClient.connect(uri, { maxPoolSize: 50, minPoolSize: 10 }) 
    Set a lower maxPoolSize and monitor connections: MongoClient.connect(uri, { maxPoolSize: 50, minPoolSize: 10 })

中文步骤

  1. 确保所有游标在try-finally块中关闭：try { cursor = collection.find(); ... } finally { cursor.close(); }
  2. 设置较低的maxPoolSize并监控连接：MongoClient.connect(uri, { maxPoolSize: 50, minPoolSize: 10 })

Dead Ends

Common approaches that don't work:

  1. 80% fail

    Leaks will still exhaust the pool eventually, and high connections may overwhelm the server.

  2. 90% fail

    The leak will reoccur and exhaust the pool again.