We're having issues with a MW installation that gets very slow when multiple users are logged in simultaneously. After a while the wiki becomes unresponsive and in some cases gives HTTP error 500. This has occurred with as few as three users logged in at once.
The wiki was installed on a Windows server 2016-server, following this guide: https://www.mediawiki.org/wiki/Manual:Installing_MediaWiki_on_Windows_Server.... My first thought was that there was too little server resources, but when I looked at the task manager, CPU was fairly consistently between 5 and 25% (there were a few spikes) and the RAM was steady at around 50%. MW version is 1.30.0.
I have turned on logging (following these instructions: https://www.mediawiki.org/wiki/Manual:How_to_debug#Logging), but I can't find any obvious cause for this behaviour. I have compiled a list of messages that looks suspicious here: https://phabricator.wikimedia.org/P6814. I didn't want to post the whole log since the logging instructions had security warnings about this.
Any help with how to proceed finding the cause for this and fixing it would be much appreciated.
All the best,
*Sebastian Berlin* Utvecklare/*Developer* Wikimedia Sverige (WMSE)
E-post/*E-Mail*: sebastian.berlin@wikimedia.se Telefon/*Phone*: (+46) 0707 - 92 03 84