Software Interup Issues

davec at davec at
Fri Dec 15 18:08:03 GMT 2006

Dear LVS Community,

I have having an issue with Software Interupts on my implementation of ipvsadm.

Here is the error:

Losing some ticks... checking if CPU frequency changed.
warning: many lost ticks.
Your time source seems to be instable or some driver is hogging interupts
rip _spin_unlock_irqrestore+0x2f/0x30
Falling back to HPET

When this happens, packets begin to drop and communication of any kinda with the server becomes quite slow.

I am running the following:

Dell 1850 - Dual Xeon 3.0GHZ (HyperThreading disabled) - 3GB RAM
RedHat EL4 ES
Linux upstream 2.6.9-42.0.3.ELsmp #1 SMP Mon Sep 25 17:24:31 EDT 2006 x86_64 x86_64 x86_64 GNU/Linux
ipvsadm v1.24 2005/12/10 (compiled with getopt_long and IPVS v1.2.0)

I am doing transparent proxy on this machine.  Core routers direct all port 80 traffic to this box.  This box has iptables rules that mark filterd IPS with a 1.  IPVSADM then load balances marked packets to 5 squid proxy machines.  (More information available upon request).  

This load takes a few days to build up b4 it causes a failure and above error.

Any help would be greatly appreciated.


Dave Cunningham
Systems Administrator

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