今天启动hbase的时候报错：

ERROR: org.apache.hadoop.hbase.ipc.ServerNotRunningYetException: Server is not running yet
  at org.apache.hadoop.hbase.master.HMaster.checkServiceStarted(HMaster.java:2261)
  at org.apache.hadoop.hbase.master.MasterRpcServices.isMasterRunning(MasterRpcServices.java:930)
  at org.apache.hadoop.hbase.protobuf.generated.MasterProtos$MasterService$2.callBlockingMethod(MasterProtos.java:55654)
  at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2180)
  at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:112)
  at org.apache.hadoop.hbase.ipc.RpcExecutor.consumerLoop(RpcExecutor.java:133)
  at org.apache.hadoop.hbase.ipc.RpcExecutor$1.run(RpcExecutor.java:108)
  at java.lang.Thread.run(Thread.java:748)

这种情况是由于不正常的关闭hadoop，从而导致hadoop进入了安全模式产生的原因。

解决方案：让hadoop退出安全模式

hadoop dfsadmin -safemode leave