IIS 7 and Above
IIS 8 Worker Processes Overload Certain Application Pool With Request...
Last post Mar 09, 2018 01:59 AM by Yuk Ding
Mar 07, 2018 06:22 PM|NiamLeeson|LINK
I've been trying to solve this problem for some time now and have only been able to put band-aid style fixes on it, not really fixing the underlying problem. I'm hoping someone here might be able to help.
I work at a college and we use IIS 8 to manage our web server, on which we host over 80 websites, all of them WordPress based. Every other day when we get to the office it seems any one of our sites is down due to a massive amount of worker processes overloading
IIS, and to fix this we go into IIS 8 and stop and restart the web server. Initially we thought this was a recycling issue and so we set the server to recycle requests periodically but eventually that became ineffective and didn't really address the underlying
problem. We believe it may have something to do with our PHP configuration, but again, we cannot seem to narrow it down. We've searched and tried different things, yet nothing seems to solve the problem.
One potential solution I came across was a tutorial explaining how to limit CPU usage after a certain threshold is met but the weird problem here is that on our web server we have sixteen separate
application pools and the CPU is never overloaded, even when the application pool in question is stuck. In other words, the other application pools continue working as they should, so I don't think this is the correct solution.
Does anyone have any idea why this happens or has anyone experienced and solved this before?
Mar 08, 2018 09:04 AM|Yuk Ding|LINK
So what did you see in IIS manager->server level->worker processes->hanged website? It will displaye the stuck module and state? If it stuck in cgi module. Then you need to focus on the PHP application itself. Maybe there is a memory leak in your wordpress
based application. In addition, have you monitored the memeory and CPU usage. In addition, could you see any thing in IIS log or event viewer?
Of course, you could try debug diagnostic to generate and analyze the dump file.
Mar 08, 2018 05:42 PM|NiamLeeson|LINK
When it happens, in the worker processes section of the hanged website there are just hundreds (maybe thousands) of requests just sitting there, piling up. I'm not sure if it is a PHP application issue or CGI module issue, I was just saying both me and
my boss suspect it may be, but we aren't sure where to look specifically. I have monitored the CPU usage of the computer and even when this happens, the CPU is not being taxed, so I don't think that's the issue. The next time it happens I will have to look
at the IIS log, and perhaps I will try the debug diagnostic but I'm not totally sure how to do that. IIS is not my specialty.
Mar 09, 2018 01:59 AM|Yuk Ding|LINK
That's why I suggest you to check the worker processes monitor. You should be able to find the hanged request in it. By the way, dump analysis is the best way to fix IIS hang issue but it require quite technology to achieve this.