[JFR] Compilation queue statistics

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    • Type: Enhancement
    • Resolution: Fixed
    • Priority: P4
    • 22
    • Affects Version/s: 17, 21, 22
    • Component/s: hotspot
    • jfr
    • b24

      The current compilation related events don't show whether you are over/under-utilizing your compilation threads; requiring you to experiment with settings to compile as fast as possible (esp in service startup/warmup)

      Proposing the following periodic event so that you can determine the pressure on the compilation queues

      You will see one event per compiler queue: c1 and c2

      The following event definition is in the form used for metadata.xml

        <Event name="CompilerQueueUtilization" category="Java Virtual Machine, Compiler" label="Compiler Queue Utilization" period="everyChunk">
          <Field type="CompilerType" name="compiler" label="Compiler" />
          <Field type="long" contentType="hertz" name="addedRate" label="Requets Added Rate" description="Requests added per second"/>
          <Field type="long" contentType="hertz" name="removedRate" label="Requests Removed Rate" description="Requests removed per second"/>
          <Field type="long" name="queueSize" label="Queue Size"/>
          <Field type="long" name="peakQueueSize" label="Peak Queue Size"/>
          <Field type="long" name="addedCount" label="Requests Added"/>
          <Field type="long" name="removedCount" label="Requests Removed"/>
          <Field type="long" name="totalAddedCount" label="Total Requests Added"/>
          <Field type="long" name="totalRemovedCount" label="Total Requests Removed"/>
          <Field type="int" name="compilerThreadCount" label="Compiler Thread Count"/>
        </Event>

      The queues already track the size, tracking peak size and added/removed count is a minor change to the compilerBroker.
      Importantly the numberOfThreads should be the current number rather than the configured number for when the dynamic compiler threads option is being used

            Assignee:
            Mat Carter
            Reporter:
            Mat Carter
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              Created:
              Updated:
              Resolved: