https://bz.apache.org/bugzilla/show_bug.cgi?id=53555
--- Comment #49 from Valentin Gjorgjioski <[email protected]> --- Hi, This started happening after recent upgrade of Ubuntu. Apache was the same, and now it is the same. Ubuntu is 14.04.5 LTS, Apache is 2.4.7. This is high load, production server. Working for 1.5 year without any problems so far. Here is some log of that update, when the problem started: [UPGRADE] apache2:amd64 2.4.7-1ubuntu4.9 -> 2.4.7-1ubuntu4.13 [UPGRADE] apache2-bin:amd64 2.4.7-1ubuntu4.9 -> 2.4.7-1ubuntu4.13 [UPGRADE] apache2-data:amd64 2.4.7-1ubuntu4.9 -> 2.4.7-1ubuntu4.13 [UPGRADE] apache2-mpm-worker:amd64 2.4.7-1ubuntu4.9 -> 2.4.7-1ubuntu4.13 [UPGRADE] apache2-utils:amd64 2.4.7-1ubuntu4.9 -> 2.4.7-1ubuntu4.13 [INSTALL] php5-mysqlnd:amd64 [UPGRADE] php5-cli:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-common:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-curl:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-fpm:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-gd:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-intl:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-pgsql:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-pspell:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-readline:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-recode:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-sqlite:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-tidy:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-xmlrpc:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5-xsl:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 [UPGRADE] php5:amd64 5.5.9+dfsg-1ubuntu4.14 -> 5.5.9+dfsg-1ubuntu4.19 Here is what I nailed it down to: 1. After this upgrade I needed to DISABLE the opcache in PHP, because problems started with fatal errors and segmentation faults with wordpress. 2. Because of the 1. the server got even higher load. 3. Higher load caused full scoreboard, and maxRequestWorkersk. What I found were two problems: 1. When high load occurs and MaxReqeustWorkers is hit, the apache stops responding (dies). It should slow down, should not accept new requests until free slot, but it shouldn't stop responding. I think I saw this reported somewhere else, e.g.: https://www.digitalocean.com/community/questions/apache2-crash-on-ubuntu-14-04-maxrequestworkers-issue 2. When I found a way to solve the problem with high load (enable wp cache plugins), now the second problem started, mainly on apache reload (log rotation) or even on regular basis WHEN MaxConnectionsPerChild is different from 0, and/or when pm.max_requests is different from 0. Why this is a problem - because children are dying after certain numbers of requests, and then they get stuck into "G" state, and never completing. This is filling your scoreboard and you are ending with that error. Once you set these to 0, problem more or less disappears. Workaround is setting these to 0, and hoping all scripts are good, no memory leaks, lowering memory usage in php.ini, and restaring the server each day (on logrotate restart and not reload). Very important trick that I learned in during this is also this one: ALWAYS restart php-fpm and apache together. Failing to do so leads to some instabilities. For me that workaround work, but I would like to hear why this happens, and how we can prevent it (especially the problem when Apache dies when MaxRequestWorkers is readched). -- You are receiving this mail because: You are the assignee for the bug. --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
