python network_error ai_generated true

sqlalchemy.exc.TimeoutError: QueuePool limit of size 5 overflow 10 reached, connection timed out, timeout 30

ID: python/sqlalchemy-connection-timeout

Also available as: JSON · Markdown · 中文
80%Fix Rate
86%Confidence
0Evidence
2024-08-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

The connection pool is exhausted because too many connections are in use, and the timeout is exceeded waiting for a free connection.

generic

中文

连接池已耗尽，因为太多连接正在使用中，等待空闲连接超时。

Workarounds

  1. 85% success Increase pool_size and overflow, and ensure connections are closed 
    engine = create_engine('postgresql://user:pass@localhost/db', pool_size=20, max_overflow=40, pool_timeout=60)
  2. 95% success Use context managers for sessions to ensure closure 
    with Session() as session:
    session.query(User).all()

Dead Ends

Common approaches that don't work:

  1. Increasing pool_size without monitoring usage 50% fail

    This may mask the underlying issue of connection leaks.

  2. Restarting the application 70% fail

    Connections may leak again if not properly closed.