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Cisco Bug: CSCvh68007 - High CPU after upgrade to version 10.0.2-020

Last Modified

Sep 14, 2018

Products (1)

  • Cisco Email Security Appliance

Known Affected Releases

10.0.2-020

Description (partial)

Symptom:
After upgrade to AsyncOS version 10.0.2-020, customer noticed high CPU utilization, upon troubleshooting we confirmed there is actually no high CPU utilization detected. The state of the ESA was up and working , processing emails correctly with no delays , no emails stuck in queue, no errors generated, no feature consuming excessive CPU, and from the logs there is no indication of high CPU load. 
We even cannot predict any CPU Utilization value to the incoming traffic. That is because the actual CPU Utilization comes from a variety of tasks, of which many are recurring/scheduled background tasks. Hence the value showing is not an accurate representation of the status of the CPU utilization. 

As an example, the security service updates (Anti Spam, Anti Virus etc.), which are typically running in 5 minute intervals, cause a CPU Utilization spike for a few seconds. When the machine is in that state already using swap memory, we will see an increased utilization due to memory transitions, and increase response time. 

Also, we see ESA in production hovering at about 50-70% CPU Utilization in the Reporting graphs. Much of the load displayed with these numbers (50-70% in the Reporting graphs) comes from recurring background tasks, like security service updates. Depending on the model, its possible that a machine with no or limited incoming mail load has this CPU consumption, just because of recurring background tasks. but this does not give an actual representation of the CPU status.

Conditions:
Running AsyncOS version 10.0.2-020

Related Community Discussions

<key>CSCvh68007</key> - High CPU after upgrade to version 10.0.2-020
Do someone knows what's the fixed version according with TAC? Or anyone that has opened a TAC case for this issue could give me the workaround that they were given?
Latest activity: Jun 12, 2018
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