hbase中对deadserver处理的困扰
hbase在一个regionServer死掉后，即使重启了这个server，deadlist中也不会去掉原先死去的deadserver。
例如：
hbase shell>status5 servers, 0 dead, 6.2000 average load
hbase-daemon.sh stop regionserver
hbase shell>status4 servers, 1 dead, 6.2000 average load
hbase-daemon.sh start regionserver
hbase shell>status5 servers, 1 dead, 6.2000 average load
public synchronized boolean add(String e) { this.numProcessing++; // Check to see if we are at capacity for dead servers if (deadServerList.size() == this.maxDeadServers) { deadServers.remove(deadServerList.remove(0)); } deadServerList.add(e); return deadServers.add(e); }