bug: The recommended value for worker_shutdown_timeout is 240 seconds.

[Miss-you]

Issue description

current

  worker_shutdown_timeout: 3s     # timeout for a graceful shutdown of worker processes

https://github.com/apache/incubator-apisix/blob/master/conf/config.yaml#L104

recommendation

  worker_shutdown_timeout: 240s     # timeout for a graceful shutdown of worker processes

reasons:

1. 3 seconds is too short, once a graceful restart will quickly disconnect the long connection
2. The default value for nginx ingress is 240 seconds.

Environment

• apisix version (cmd: apisix version):
• OS:

Minimal test code / Steps to reproduce the issue

What's the actual result? (including assertion message & call stack if applicable)

What's the expected result?

[moonming]

@Miss-you agreed , welcome PR

[shuaijinchao]

the problem has been fixed, I will close this issue.