Regarding the number of metrics actually clamped by the Java agent property "introscope.agent.metricClamp"

Products

• CA Application Performance Management (APM / Wily / Introscope)
• DX Application Performance Management

Issue/Introduction

Using a java agent with the following settings for Java agent property "introscope.agent.metricClamp"

It was actually clamped at 6512 metrics although property was set at "introscope.agent.metricClamp=6520"

The manual says "Approximate number of metric clamps sent by the agent to the Enterprise Manager."

Is it possible to guess how many are actually clamped? For example, is there a rule that it will always be 8 metrics less than the set value?

 

Can see in IntroscopeAgent.log

5/18/23 02:06:32 午後 JST [DEBUG] [IntroscopeAgent.JMX Service] DIAG: setContextAndPoll exit called - fCanRunForcedDiscovery = false(0 uS)
5/18/23 02:06:33 午後 JST [WARN] [IntroscopeAgent.Agent] Absolute metric clamp of 6520 reached, no more metrics can be created.  Instrumentation on this application should be reduced.

 

Environment

Release : 10.7.0 SP2

Resolution

So the root cause is the APM agent sometimes allocates metrics to some tracers but they don't get any data and not reported to EM

So when this happens we see some difference in metric count in investigator and metric clamp configured in agent. This will not have any impact on functionality