We are sporadically experiencing high CPU with our Apache instances. The CPU averages about 5% utilization normally and has run fine for over a year without an issue but over the past month we see spikes up to 100% utilization that never drop until the instance is bounced. We can go up to a week before we see the issue but we've also seen it happen multiple times in a day. The logs are not indicating any errors for further investigation and we only have this issue in our Production environment. Things we've tried: -We've searched numerous topics on Apache HTTPD and high CPU and with regards to tuning parameters but considering we haven't had an increase in usage and our average CPU utilization is normally low we are reluctant to make tuning changes without understanding what else we may impact. -We ran prstat and the one anomaly we've seen is the Involuntary Context Switching (ICX) seems to be high when the CPU spikes. Normally ICS is in the single digits but when the CPU spikes we see thousands. From observation it appears that the ICX value and CPU utilization increase and drop simultaneously. Information regarding our environment: - Apache HTTPD 2.2.20 - MOD_PROXY as a reverse proxy - Solaris 10 - 2 servers for high availability and have experienced the issue on both servers One other note is that we are using CA's SiteMinder (authentication and authorization) agent for Apache. We've exhausted all of the support CA will give us regarding this issue and they have no other known issues from their customer base. Thanks, Bill --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
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