We had a similar issue with Keep-Alives so I catch USR1 in the application
code and set a flag and then at the end of that request I set connection
closed header and call child_terminate to kill off that child.
IIRC, MaxRequestsPerChild doesn't include the number of keep-alive
requests, so another thing to keep in mind.
Did you try reducing the keep-alive timeout? 60 seconds seems like a long
time to tie up a process.
On Tue, Nov 15, 2016 at 10:59 AM, Alex Kaiser <alextkai...@gmail.com> wrote:
> Hello,
>
> I am having trouble gracefully draining connections from httpd when we
> have KeepAlive turned on. The problem seems specific to idle KeepAlive
> connections. It looks like when a process has an established KeepAlive
> connection and we send the main httpd process a WINCH or a USR1 signal, the
> KeepAlive connection will stay alive until it gets another request, and
> then once it is finished with that request it will shut down. However, if
> it doesn't get another request on the connection, the process will hang
> around fro KeepAliveTimeout since you issued the signal. I would like for
> idle KeepAlive connections to shut down immediately, is this not
> technically possible for some reason? If it is possible, is it a bug that
> the connections stick around?
>
> The problem with them sticking around, is that when I want to fully shut
> down the server some of these KeepAlive connections might finally get a
> request, and thus if I hard kill a server before waiting KeepAliveTimeout,
> browsers can see errors.
>
> When I look at the server-status page, these processes change from K to G
> immediately, but will stay in the G mode the whole time they are waiting.
> When the mode of operation changes the SS column (seconds since last
> requests) doesn't get reset and will keep going up, so this could possibly
> go all the way up to KeepAliveTimeout * 2 if you start the restart process
> when a connection is near the KeepAliveTimeout.
>
> I've done most of my testing using Apache httpd 2.2.31 with mod_jk 1.2.31,
> I also did some testing with Apache httpd 2.4.23 with mod_jk 1.2.42 and saw
> the same behavior. I did most of my testing using the prefork module, but
> I also saw the same behavior when I twas testing with the event module.
> The KeepAlive settings I was using are:
>
> KeepAlive on
> KeepAliveTimeout 60
> MaxKeepAliveRequests 100
>
> The small python script I was using to test keepAlive connections (the
> behavior was the same when I was testing using browsers):
>
> import requests
> import time
>
> s = requests.Session()
> r = s.get("<server address>")
> print("Sleeping")
> time.sleep(500)
>
>
> Thanks,
> Alex Kaiser
>
--
Bill Moseley
mose...@hank.org
