void onJobResultProcessingStart() {
    jobResultProcessingStartTimeMs = System.currentTimeMillis();
    if (jobCallbackProcessingCompleteTimeMs != UNINITIATED) {
      cryptoJobMetrics.jobResultProcessingWaitTimeMs.update(
          jobResultProcessingStartTimeMs - jobCallbackProcessingCompleteTimeMs);
    }
  }
Signifies that the job result processing has started
ambry-router/src/main/java/com/github/ambry/router/NonBlockingRouterMetrics.java