[SAC] xblade14 distress


We have suffered problems on xblade14 again this morning.

The load average was through the roof and swap space was exhausted.
Thankfully John was able to power cycle the system and we regained control.

We saw some more weird web traffic spikes after reboot, and I managed
to catch the following server status during one odd jerk.


It appears like there was a sudden storm of connection requests which
never proceeded past the initial connection step.

I had already set the maximum number of servers down from 256 to 32 in this
block of the conf:

<IfModule prefork.c>
StartServers 8
MinSpareServers 5
MaxSpareServers 20
ServerLimit 32
MaxClients 256
MaxRequestsPerChild 4000

And there was no serious problems with load on the system. I suspect
(without much real evidence) that this sort of connection storm was previously
causes lots of servers to fire up and this lead to system overload. Perhaps
we will now handle them better albiet with the risk of refusing valid
connections due to lack of servers. Those with better understanding of apache
than me are encouraged to review my opinions and correct me.

I'll try to keep an eye on the system.

Best regards,
I set the clouds in motion - turn up | Frank Warmerdam, warmerdam@pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush | Geospatial Programmer for Rent