python system_error ai_generated true

RuntimeError: Lifespan protocol error: received 'lifespan.shutdown' before 'lifespan.startup.complete'

ID: python/starlette-asgi-lifespan-error

Also available as: JSON · Markdown · 中文
80%Fix Rate
81%Confidence
0Evidence
2024-09-14First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

The ASGI server sent a shutdown signal before the startup completed, often due to an error in the startup handler.

generic

中文

ASGI服务器在启动完成前发送了关闭信号，通常是由于启动处理器中出现错误。

Workarounds

  1. 90% success Fix the error in the startup handler 
    @app.on_event('startup')
async def startup():
    try:
        # initialization code
    except Exception as e:
        print(f"Startup error: {e}")
  2. 85% success Use try-except in lifespan context manager 
    @asynccontextmanager
async def lifespan(app):
    try:
        await startup()
        yield
    finally:
        await shutdown()

Dead Ends

Common approaches that don't work:

  1. Ignoring the error and restarting the server 70% fail

    Error will recur if the startup handler still fails.

  2. Removing the lifespan handler entirely 60% fail

    Removes startup/shutdown functionality, but may hide important initialization.