Issue #4047 Graceful Cleanup

[gregw]

Initially created to just address #4047, this PR has now started addressing other graceful shutdown issues (in preparation for HTTP/2 graceful). See also #4100 for the core fix

Signed-off-by: Greg Wilkins gregw@webtide.com

[gregw]

I've taken this out of 9.4.22... I'm not even sure it should be in 9.4.x

[gregw]

I'm going to rebase this on jetty-10

[alefab]

I've taken this out of 9.4.22... I'm not even sure it should be in 9.4.x

I was searching a way to wait for requests to be handled during shutdown and I find this ticket.
Is there any issue for this ticket not being fixed in the 9.4.x branches ?

[gregw]

@alefab There is graceful shutdown support in both 9 and 10. This issue is about cleaning up the implementation.

If you install the stats handler and set the stopTimeout then you'll get graceful shutdown behaviour.

[alefab]

@gregw Thanks ! After adding a stats handler, the graceful shutdown is working like a charm (9.4.31) :)

[gregw]

I know that is kind of counter intuitive..... but counting request can be expensive and cause contention. So if we have to do it, we only want to do it once, hence we make it optional in the stats handler and then hang graceful shutdown off that.

@sbordet in Jetty-10 I guess we could add a graceful-shutdown.mod that depends on the stats.mod ?