附录A
常见问题
本附录将汇总一些HBase集群线上环境可能遇到的常见问题，分析问题产生的原因，并给出解决方案，开发人员或者运维人员在线上遇到类似问题时可以直接将其作为参考。
A.1
垃圾回收超时导致分区服务器宕机
根据我多年的一线经验，该问题是HBase线上出现最频繁的问题之一。HBase分区服务器启动一段时间后自动宕机，HBase日志文件输出如下日志：
2018-02-23 08:55:35,026 WARN [JvmPauseMonitor] util.JvmPauseMonitor: Detected pause in JVM or host machine (eg GC): pause of approximately 25883ms
GC pool 'ParNew' had collection(s): count=1 time=26192ms..................2018-02-23 08:55:55,205 WARN [B.defaultRpcServer.handler=157,queue=17,port=16020]regionserver.MultiVersionConcurrencyControl: STUCK: MultiVersionConcurrencyControl{readPoint=38025361, writePoint=38025365}2018-02-23 08:55:55,205 WARN [B.defaultRpcServer.handler=27,queue=7,port=16020]regionserver.MultiVersionConcurrencyControl: STUCK: MultiVersionConcurrencyControl{readPoint=38025361, writePoint=38025365}2018-02-23 08:55:55,271 WARN [hconnection-0x66ef393c-shared--pool3-t3738200]client.AsyncProcess: #3, table=s_call, attempt=4/4 failed=20ops, last exception:org.apache.hadoop.hbase.regionserver.RegionServerAbortedException: org.apache.hadoop.hbase.regionserver.RegionServerAbortedException: Server slave7,16020,1506416633339 aborting at org.apache.hadoop.hbase.regionserver.RSRpcServices.checkOpen(RSRpcServices.java:1093) at org.apache.hadoop.hbase.regionserver.RSRpcServices.multi(RSRpcServices.java:2078) at org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ClientService$2.callBlockingMethod(ClientProtos.java:33656) 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:745) on slave7,16020,1506416633339, tracking started Fri Feb 23 08:55:54 CST 2018;not retrying 20 - final failure2018-02-23 08:55:55,414 FATAL [regionserver/slave7/172.168.0.7:16020] regionserver.HRegionServer: ABORTING region server slave7,16020,1506416633339: org.apache.hadoop.hbase.YouAreDeadException: Server REPORT rejected; currently processing slave7,16020,1506416633339 as dead server