[HBASE-1314] master sees HRS znode expire and splits log while the HRS is still running and accepting edits

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 0.20.0
• Fix Version/s: 0.20.0
• Assignee: Unassigned
• Reporter: Andrew Kyle Purtell
• Created: 07/Apr/09 04:48
• Updated: 13/Sep/09 22:24
• Resolved: 09/Jun/09 23:01

Description

ZK session expiration related problem. HRS loses its ephemeral node while it is still up and running and accepting edits. Master sees it go away and starts splitting its logs while edits are still being written. After this, all reconstruction logs have to be manually removed from the region directories or the regions will never deploy (CRC errors). I think on HDFS edits would be lost, not corrupted. (I am using a HBase root on local file system.)

HRS ZK session expires, causing its znode to go away:

2009-04-07 03:50:39,953 INFO org.apache.hadoop.hbase.master.ServerManager: localhost.localdomain_1239068648333_60020 znode expired
2009-04-07 03:50:40,565 DEBUG org.apache.hadoop.hbase.master.HMaster: Processing todo: ProcessServerShutdown of localhost.localdomain_1239068648333_60020
2009-04-07 03:50:40,637 INFO org.apache.hadoop.hbase.master.RegionServerOperation: process shutdown of server localhost.localdomain_1239068648333_60020: logSplit: false, rootRescanned: false, numberOfMetaRegions: 1, onlineMetaRegions.size(): 1

But here we have the HRS still reporting in, triggering a LeaseStillHeldException:

2009-04-07 03:50:40,826 INFO org.apache.hadoop.ipc.HBaseServer: IPC Server handler 2 on 60000, call regionServerReport(address: 127.0.0.1:60020, startcode: 1239068648333, load: (requests=14, regions=7, usedHeap=582, maxHeap=888), [Lorg.apache.hadoop.hbase.HMsg;@6da21389, [Lorg.apache.hadoop.hbase.HRegionInfo;@2bb0bf9a) from 127.0.0.1:39238: error: org.apache.hadoop.hbase.Leases$LeaseStillHeldException
org.apache.hadoop.hbase.Leases$LeaseStillHeldException
at org.apache.hadoop.hbase.master.ServerManager.regionServerReport(ServerManager.java:198)
at org.apache.hadoop.hbase.master.HMaster.regionServerReport(HMaster.java:601)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.hbase.ipc.HBaseRPC$Server.call(HBaseRPC.java:632)
at org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:909)

And log splitting starts anyway:

2009-04-07 03:50:41,139 INFO org.apache.hadoop.hbase.regionserver.HLog: Splitting 3 log(s) in file:/data/hbase/log_localhost.localdomain_1239068648333_60020
2009-04-07 03:50:41,139 DEBUG org.apache.hadoop.hbase.regionserver.HLog: Splitting 1 of 3: file:/data/hbase/log_localhost.localdomain_1239068648333_60020/hlog.dat.1239075060711
[...]

Issue Links

• relates to: HBASE-1315 when HRS znode expires while HRS is still running, HRS enters infinite loop
• relates to: HBASE-1439 race between master and regionserver after missed heartbeat