Try this: https://httpd.apache.org/docs/2.4/programs/rotatelogs.html <https://httpd.apache.org/docs/2.4/programs/rotatelogs.html>
> On 29 Mar 2021, at 13:45, A.J. Gatlin <ajgat...@gmail.com> wrote: > > Hi there, > > I'm running some PHP-based sites on CentOS 8, which uses version 2.4.37 of > Apache. Apache is set to use MPM Event mode, which is also the default. > > Once per day during a quiet period, logrotate rotates the Apache logs by > doing a graceful restart (reload) as part of a postrotate command: > > /bin/systemctl reload httpd.service > /dev/null 2>/dev/null || true > > This causes the following line to appear in the Apache error log, which I > believe to be normal and expected: > > [mpm_event:notice] [pid 1413:tid 140292271810880] AH00493: SIGUSR1 received. > Doing graceful restart > > The log is then rotated, and in the newly created error log, I see the > following: > > [lbmethod_heartbeat:notice] [pid 1413:tid 140292271810880] AH02282: No > slotmem from mod_heartmonitor > [mpm_event:notice] [pid 1413:tid 140292271810880] AH00489: Apache/2.4.37 > (centos) OpenSSL/1.1.1g configured -- resuming normal operations > [core:notice] [pid 1413:tid 140292271810880] AH00094: Command line: > '/usr/sbin/httpd -D FOREGROUND' > > Then, immediately after, I see this error repeated once per second: > > [mpm_event:error] [pid 1413:tid 140292271810880] AH03490: scoreboard is full, > not at MaxRequestWorkers.Increase ServerLimit. > > The server then becomes unresponsive and will not answer HTTPS requests. It > continues logging the above error and will not begin working again until I > manually restart the Apache process. > > All configs on this server are essentially the default for CentOS 8. I have > not tried making any adjustments to the MPM Event config settings -- mostly > because I'm not sure what setting for ServerLimit would be "correct," and > also because this problem happens *only* when logrotate does its graceful > restart, and not during other periods of high traffic. > > My research on this issue brings up a lot of results about an old Apache bug > related to MPM Event mode, but my version of Apache shouldn't be affected by > this particular bug. I have also seen suggestions that some long-running > processes may hang and eat up all available worker processes, but I don't > understand why this would interrupt the restart. And I don't have any > particularly long-running processes served by Apache -- just quickly > executing PHP scripts. > > Can anyone suggest what might fix this issue, given that it seems to happen > only during a graceful reload? Should I try changing the method that > logrotate uses to restart Apache? > > Is there some other way I can avoid the server hanging, or is it really > necessary to increase the ServerLimit as the error suggests? > > Thank you very much for any insight or help.
