Server "Crashing" (no connect) During Traffic Spikes w/o increase in load

I’m somewhat puzzled.

I’m used to getting traffic spikes and seeing my load spike to 70+ and therefore my server struggle. It sometimes will go down, but i can at least see it coming with load.

Lately, however, if my server takes a massive spike in traffic it goes down (or at least loses connection) without ever increasing in load. I do see the ram come close to maxing out during this time, and that’s my only real indicator that we’re about to go down. But I can’t really call it crashing, as the server reports no interference in up time.

So strange. If it gets hit hard, it just refuses to accept any more traffic and remains unable to connect until the spike has diminished.

I think I have some setting in apache telling it to not accept any more connections rather than increase its load.

What should I look for on the onset of the next spike? What could be causing this?

All suggestions appreciated.

Cheers
Ryan

Ryan,

Some information about a problem there but nothing telling us you’re even using Apache, the OS, the type of account you have, etc. Not that much of that matters (and you are in the Apache forum) as I suspect that it’s a hosting limit which is causing your server to terminate services (including your http daemon - at least limiting new child processes) as your CPU/RAM is approaching your limits.

Is that what your host is telling you (or are you on an unmanaged VPS/Dedicated server?)

Regards,

DK

I’m on a dedicated server.

Dual 54xx series, 8GB ram, Raid-1 SAS SCSI.

Using Apache. CentOS 5.x

I have no hosting limit, save for my 1Gbps port.

If there’s something holding it up, there’s got to be a setting in httpd.conf or my.cnf that I can play with.

Thanks
Ryan

Ryan,

I’d look at the Apache child limits. Apache spawns child processes to sit ready to handle new requests. With a limit on those, it will not be able to handle spikes like you’re describing. Raise the limit and see if the problem lessens (or, hopefully, goes away).

Regards,

DK

Thanks.

I’ll definitely have a look at that.

Is there a command in SHH to show how many child processes are currently running? Just so I can compare to limit.

Cheers
Ryan

Ryan,

There probably is but that’s a Linux thing and I’ll admit to being weak there.

Regards,

DK