hbase错误记录部分总结

2019-03-18 10:21:01,623 [pool-5-thread-1-EventThread] WARN  org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation - This client just lost it‘s session with ZooKeeper, closing it. It will be recreated next time someone needs it
 org.apache.zookeeper.KeeperException$SessionExpiredException: KeeperErrorCode = Session expired
        at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.connectionEvent(ZooKeeperWatcher.java:677)
        at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.process(ZooKeeperWatcher.java:609)
        at org.apache.hadoop.hbase.zookeeper.PendingWatcher.process(PendingWatcher.java:40)
        at org.apache.zookeeper.ClientCnxn$EventThread.processEvent(ClientCnxn.java:522)
        at org.apache.zookeeper.ClientCnxn$EventThread.run(ClientCnxn.java:498)
2019-03-18 10:21:18,758 [pool-5-thread-1-EventThread] INFO  org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation - Closing zookeeper sessionid=0x1697f22c8e70014
 2019-03-18 10:21:18,816 [pool-5-thread-1-EventThread] INFO  org.apache.zookeeper.ClientCnxn - EventThread shut down
 
 分析：往hbase插入大量数据的时候，client连接超时。
 可能原因：
 (1)、hbase内存堆大小设置太小，修改hbase-env.sh文件，把堆大小设置大一些。eg：export HBASE_HEAPSIZE=30720
 (2)、hadoop内存堆设置太小，修改hadoop-env.sh，把堆大小设置大一些。eg：export HBASE_HEAPSIZE=8192。默认是1000m
 (3)、zk最大连接数过小
 默认值是300，在查询量与记录数量特大的集群中，可能会造成相互间通信连接过多从而拒绝连接服务。
<property>
<name>hbase.zookeeper.property.maxClientCnxns</name>
<value>15000</value>
</property>

INFO  [regionserver60020] regionserver.HRegionServer: STOPPED: Unhandled: org.apache.hadoop.hbase.ClockOutOfSyncException: 
Server slave2,60020,1405560498057 has been rejected; Reported time is too far out of sync with master.  Time difference of 28804194ms > max allowed of 30000ms
分析：根据错误日志，可得到slave2和maste机器时间差太多，查看各个系统的时间，果真如此，同步即可。另外一种方法就是配置hbase的配置文件：
解决：
<property>
 <name>hbase.master.maxclockskew</name>
 <value>200000</value>
 <description>Time difference of regionserver from master</description>
</property>
尽量同步时间