Hbase集群搭建最常见的问题及解决办法
问题一：使用自己搭建的zookeeper集群而不使用hbase自带的zookeeper解决办法？
首先：在hbase-env.sh中修改如下参数:
屏蔽hbase自带的zookeeper
问题二：通过start-abase.sh启动hbase集群发现从节点报如下错误：
30 14:02:05,999 FATAL [regionserver60020] regionserver.HRegionServer: Master rejected startup because clock is out of sync
org.apache.hadoop.hbase.ClockOutOfSyncException: org.apache.hadoop.hbase.ClockOutOfSyncException: Server heres01,60020,1493532120370 has been rejected; Reported time i
s too far out of sync with master. Time difference of 2421573ms>max allowed of 30000ms
at org.apache.hadoop.hbase.master.ServerManager.checkClockSkew(ServerManager.java:314)
at org.apache.hadoop.hbase.master.ServerManager.regionServerStartup(ServerManager.java:215)
at org.apache.hadoop.hbase.master.HMaster.regionServerStartup(HMaster.java:1292)
at org.apache.hadoop.hbase.protobuf.generated.RegionServerStatusProtos$RegionServerStatusService$2.callBlockingMethod(RegionServerStatusProtos.java:5085)
at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2185)
at org.apache.hadoop.hbase.ipc.RpcServer$Handler.run(RpcServer.java:1889)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at org.apache.hadoop.ipc.RemoteException.instantiateException(RemoteException.java:106)
at org.apache.hadoop.ipc.RemoteException.unwrapRemoteException(RemoteException.java:95)
at org.apache.hadoop.hbase.protobuf.ProtobufUtil.getRemoteException(ProtobufUtil.java:277)
at org.apache.hadoop.hbase.regionserver.HRegionServer.reportForDuty(HRegionServer.java:1955)
at org.apache.hadoop.hbase.regionserver.HRegionServer.run(HRegionServer.java:794)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.hadoop.hbase.ipc.RemoteWithExtrasException(org.apache.hadoop.hbase.ClockOutOfSyncException): org.apache.hadoop.hbase.ClockOutOfSyncException: Ser
ver heres01,60020,1493532120370 has been rejected; Reported time is too far out of sync with master. Time difference of 2421573ms>max allowed of 30000ms
at org.apache.hadoop.hbase.master.ServerManager.checkClockSkew(ServerManager.java:314)
at org.apache.hadoop.hbase.master.ServerManager.regionServerStartup(ServerManager.java:215)
at org.apache.hadoop.hbase.master.HMaster.regionServerStartup(HMaster.java:1292)
at org.apache.hadoop.hbase.protobuf.generated.RegionServerStatusProtos$RegionServerStatusService$2.callBlockingMethod(RegionServerStatusProtos.java:5085)
at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2185)
at org.apache.hadoop.hbase.ipc.RpcServer$Handler.run(RpcServer.java:1889)
at org.apache.hadoop.hbase.ipc.RpcClient.call(RpcClient.java:1454)
at org.apache.hadoop.hbase.ipc.RpcClient.callBlockingMethod(RpcClient.java:1658)
at org.apache.hadoop.hbase.ipc.RpcClient$BlockingRpcChannelImplementation.callBlockingMethod(RpcClient.java:1716)
at org.apache.hadoop.hbase.protobuf.generated.RegionServerStatusProtos$RegionServerStatusService$BlockingStub.regionServerStartup(RegionServerStatusProtos.java
:5402)
at org.apache.hadoop.hbase.regionserver.HRegionServer.reportForDuty(HRegionServer.java:1953)
... 2 more
出现该问题的原因：因为整个集群时间没有统一，导致master连接slave超时，所以导致从节点的HRegionServer进程没有正常启动，
解决办法：
1⃣️.在hbase-site.xml文件中 修改增加 ，将时间改大点
<property>
<name>hbase.master.maxclockskew</name>
<value>150000</value>
</property>
2⃣️.修改日期
date -s 11/23/2013
修改时间
date -s 15:14:00
检查硬件（CMOS）时间
clock -r
这个修改在系统重启后就失效了，因此为了将这个时间永久生效，需要将修改的时间写入CMOS。
clock -w
