*Some* domains on server randomly stop working; reboot to solve

[Ishware]

Recently, I've gotten complaints from a couple of users that their websites have been going offline - Firefox says the connection was reset, and Chrome gives a 3xx error code. Also, Down For Everyone Or Just Me -> Check if your website is down or up? says the site is down when this happens.

So far, rebooting the server solves.

While this is happening, other sites on the same shared IP work perfectly fine.

Can anyone point me on where to *start* figuring out WTF the problem is? heh. Thank you for any advice!

 

[quietFinn]

1st place to check would be /usr/local/apache/logs/error_log

 

[Ishware]

Lots of memory issues - php trying to allocate huge amounts. Most of the entries don't tell me what script, but the ones that have a referrer seem to be spread out over all the server sites...

Now, that makes me worried I've been compromised - so I did several things, including finding all the php files modified within the last month. I've checked them all out - not many, mostly me - and there's absolutely nothing nefarious there.

What would you look at next? Is is possible I'm having hardware issues - real RAM issues - or would you still suspect software. And if the latter - what next?

Thank you for helping; I'm a Windows geek, but still relatively a Linux newbie, though I'm trying to learn as I go.

Typical entry: http://i.imgur.com/344ExIH.png

 

[quietFinn]

That "typical entry" shows that memory_limit in php.ini is 16MB, and that is way too low.

Go to WHM-> Service Configuration-> PHP Configuration Editor
and change memory_limit to 64MB

But that hardly explains why "*Some* domains on server randomly stop working", but you should do that change and see if it helps.

I suggest you use a utility called sys-snap, basic instructions for it you find here:
http://forums.cpanel.net/f5/server-...ull-since-last-update-246452.html#post1019842

 

[Ishware]

Should've mentioned - I'd bumped it to 128MB long ago; dropped to 16M as a part of testing today... (seems to work better after a reboot so far, with 16M limit, but going to play with 64M, maybe even 128M again and see it the failures come back - try to eliminate that as a cause)

I'll give that utility a check - seems like something useful. Thanks!