private ExecutorService getShutdownAllExecutorService(int size) {
    int poolSize = shutdownAllPoolSize == -1 ? size : shutdownAllPoolSize;
    return newFixedThreadPool(poolSize, "ShutdownAll-", true);
  }
Close the distributed system, cache servers, and gateways. Clears the rootRegions and
partitionedRegions map. Marks the cache as closed.

@see SystemFailure#emergencyClose()
geode-core/src/main/java/org/apache/geode/internal/cache/GemFireCacheImpl.java