@Override
    public String toString() {
      return "min worker threads=" + minWorkerThreads + ", max worker threads=" + maxWorkerThreads
        + ", max queued requests=" + maxQueuedRequests;
    }
Time to wait after interrupting all worker threads. This is after a clean shutdown has been
attempted.
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift/TBoundedThreadPoolServer.java