Provided that the EM has the appropriate capacity to handle increased load, increase the agent metric limits to allow more new metrics to be reported. The agent metrics limit is defined in the apm-events-thresholds-config.xml by the property "introscope.enterprisemanager.agent.metrics.limit"
Alternatively, modify agent pbd files to reduce instrumentation accordingly hence reducing number of metrics reported.
More details of the "introscope.enterprisemanager.agent.metrics.limit" property can be found in the CA APM Configuration and Administration Guide as follows:
An inappropriately configured agent can create thousands of metrics in quick succession, overloading the Enterprise Manager.
Use this property to prevent metric overload. If an agent generates more than the specified number of metrics, the Enterprise Manager drops them. If this situation occurs, modify the agent configuration to reduce the volume of metrics reported.
This clamp property works with the introscope.agent.metricClamp property located in the Introscope.Agent.profile file.
If introscope.enterprisemanager.agent.metrics.limit clamp value is triggered before the introscope.agent.metricClamp value, then the Enterprise Manager reads agent metrics but does not report them in the Investigator metric browser tree.
If the introscope.agent.metricClamp clamp value is triggered before the introscope.enterprisemanager.agent.metrics.limit clamp value, the agent stops sending metrics to the Enterprise Manager.