high latency

Arvind.Kumar · ‎06-17-2010

we facing performance issues where we have some server which are behind PIX firewall. The latency to the servers increase at certain times for 2-3 hrs and this goes upto 30-40ms while during other times this remains 1-2 ms. The performance with other server on the same LAN whose traffic is not passed through firewall remains normal. There is nothing abnormal with the server or any performance issues. We checked infrastructure and couldn't see an issue. Is there anyting overlooked and help to resolve the issue.

Ganesh Hariharan · ‎06-18-2010

we facing performance issues where we have some server which are behind PIX firewall. The latency to the servers increase at certain times for 2-3 hrs and this goes upto 30-40ms while during other times this remains 1-2 ms. The performance with other server on the same LAN whose traffic is not passed through firewall remains normal. There is nothing abnormal with the server or any performance issues. We checked infrastructure and couldn't see an issue. Is there anyting overlooked and help to resolve the issue.

Hi,

Just chck whenever your latency goes up at that any specific scehduler is happening on server like backup or any other activity,and also check the process conusme at the time of problem both at pix and server,it will give a hint to toruble shoot the problem.

Hope to Help !!

Ganesh.H

Arvind.Kumar · ‎06-18-2010

We have checked the server and there isn't any batch/schedule jobs running on the server, also PIX memory and CPU utilization is normal.

Brian Beijl · ‎06-18-2010

Hi,

Have you ruled out the possibility that the high latency is caused by more traffic passing through because there are more users on the network surfing the web or something? So, is this happening during peak hours, or very randomly, in which case this could also happen in the middle of the night?

At this point it could still be anything. You mention a server on the same lan segment as the server with the high latency problems. Albeit this server not being behind a PIX, You didn't tell us if that server is hosting the same services as the high latency one. Maybe it's serving completely different services in which case you can't really use it as an comparison.

Heck, it could even be a timed ACL kicking out a few links, so you have more hops to the destination

I'd double check the traffic flow during those high latency times. Chances are you have more traffic because there are more users on the network.

Regards,

Brian Beijl

Arvind.Kumar · ‎06-21-2010

The traffic is definetely not user generated, its happening randomly however with all the servers at the same timings. No ACL kicking in. Is there any tool to capture traffic as the switchport interface shows not much traffic. I have used wireshark and couldn't gather any relevant clue and core device don't support Netflow to capture any report.