Apache workers unusual peak

[pagchen]

Hi,
I got many httpd restart this morning due to connections limit and when checking configserver system info looking for any clue I found the apache worker graph showing intance peaking (see joined screenshot).

What would cause a worker peak like such ? I see no specific clue in apache's error_log?

What would you do in my position, just raise my max_client setting (now default to 150)?

Server is quite beefy with 24Gb ram and 4 duo-core Xeon(R) CPU E5606 @ 2.13GHz processors.

Many thanks,

 

[cPanelJamyn]

It's not easy to tell from just the graph. Some potential causes:

- Hung or slow sub-processes,
- DDOS attack,
- poorly optimized site/page,
- overloaded DB server delaying everything else.

What was the site traffic like around that time? Did any virtual hosts have a larger than normal amount of activity?

 

[pagchen]

Hi Jamyn,
That is the only sign of abnormal activity I found, Mysql connections/load were fine.
Which log could tell me the traffic at that time? Do I need to go through all domlogs for each host?
Is there any guide to help troubleshoot server problems?
Thanks

 

[JamesOakley]

Are you on 11.36? Did you enable e-mail auto-discovery for Outlook / Thunderbird?