@Override
    public void afterStart() {
      if (numProcessorsToStart.decrementAndGet() == 0) {
        appStatus = ApplicationStatus.Running;
      }
      userDefinedProcessorLifecycleListener.afterStart();
    }
Defines a specific implementation of {@link ProcessorLifecycleListener} for local {@link StreamProcessor}s.
samza-core/src/main/java/org/apache/samza/runtime/LocalApplicationRunner.java