Agent going into status of CPU WAIT without high CPU usage

Document ID : KB000090469
Last Modified Date : 14/04/2018
Show Technical Document Details
Issue:
Agent going into status of CPU WAIT without high CPU usage
Resolution:

Applicable to Applications Manager Versions:  v7.1, v8.0

Symptoms

The Agent stops working and goes into status of CPU WAIT. This is normal behavior if the CPU usage is higher than the CPU limit setting for the Agent, which is 80 by default. There are cases where the CPU usage is below the limit and the Agent still goes into a CPU WAIT status. This behavior has predominantly been seen in virtual environments.


Cause

The CPU usage is read by a vmstat process that is spawned off on the Remote Agent machine where Applications Manager runs. In a virtual environment, vmstat sometimes reports the usage incorrectly, which can lead to the Agent going into CPU WAIT status although there are resources available on the machine.


Resolution

The CPU limit can be set to 99, which disables the CPU observation feature:

1. Go to Object Admin -> Administration -> open the Agent in question

2. Change the field 'CPU Limit' to 99

3. Save the changes and restart the Agent processes

This means that the Agent will continue to process work even if the CPU limit is at 100%. In cases like the above, this can be beneficial.  However, if the system's CPU usage is actually high, that would require additional investigation.