@Override
    public void publish(ClusterMetrics cs) {
      LOG.info("PUBLISH {}", cs);
      channel.writeAndFlush(cs).syncUninterruptibly();
    }
Get the servers which died since a given timestamp. protected because it can be subclassed by
the tests.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/ClusterStatusPublisher.java