private Executor getSerialExecutor(InternalDistributedMember sender) {
    if (MULTI_SERIAL_EXECUTORS) {
      return serialQueuedExecutorPool.getThrottledSerialExecutor(sender);
    } else {
      return serialThread;
    }
  }
Returns the executor for the given type of processor.
geode-core/src/main/java/org/apache/geode/distributed/internal/ClusterOperationExecutors.java