Hi ,all I deploy Hbase0.98.6-cdh5.2.0 on 3 machine:
l-hbase1.dev.dba.cn0(hadoop namenode active, HMaster active) l-hbase2.dev.dba.cn0(hadoop namenode standby, HMaster standby, hadoop datanode) l-hbase3.dev.dba.cn0(regionserver, hadoop datanode) Then I shutdown the l-hbase1.dev.dba.cn0, But HBase can not work until about 15mins later. I check the log and find the following log in the region server’s log: 2014-12-05 12:03:19,169 WARN [regionserver60020-WAL.AsyncSyncer0] hdfs.DFSClient: Slow waitForAckedSeqno took 927762ms (threshold=30000ms) 2014-12-05 12:03:19,186 INFO [regionserver60020-WAL.AsyncSyncer0] wal.FSHLog: Slow sync cost: 927779 ms, current pipeline: [10.86.36.219:50010] 2014-12-05 12:03:19,186 DEBUG [regionserver60020.logRoller] regionserver.LogRoller: HLog roll requested 2014-12-05 12:03:19,236 WARN [regionserver60020-WAL.AsyncSyncer1] hdfs.DFSClient: Slow waitForAckedSeqno took 867706ms (threshold=30000ms) It seems the WAL Asysnc took too long time for region server recovery? I don’t know if the log matters ? Can any body explain the reason? and how to reduce the time for recovery?
