chunhui shen created HBASE-9810:
-----------------------------------

             Summary: Global memstore size will be calculated wrongly if 
replaying recovered edits throws exception
                 Key: HBASE-9810
                 URL: https://issues.apache.org/jira/browse/HBASE-9810
             Project: HBase
          Issue Type: Bug
            Reporter: chunhui shen
            Assignee: chunhui shen
            Priority: Critical


Recently we encountered such a case in 0.94-version:

Flush is triggered frequently because:

{format}DEBUG org.apache.hadoop.hbase.regionserver.MemStoreFlusher: Flush 
thread woke up because memory above low water=14.4g
{format}

But, the real global memstore size is about 1g.

It seems the global memstore size has been calculated wrongly.


Through the logs, I find the following root cause log:
{format}
ERROR org.apache.hadoop.hbase.regionserver.handler.OpenRegionHandler: Failed 
open of region=notifysub2_index,\x83\xDC^\xCD\xA3\x8A<\x
E2\x8E\xE6\xAD!\xDC\xE8t\xED,1379148697072.46be7c2d71c555379278a7494df3015e., 
starting to roll back the global memstore size.
java.lang.NegativeArraySizeException
        at org.apache.hadoop.hbase.KeyValue.getFamily(KeyValue.java:1096)
        at 
org.apache.hadoop.hbase.regionserver.HRegion.replayRecoveredEdits(HRegion.java:2933)
        at 
org.apache.hadoop.hbase.regionserver.HRegion.replayRecoveredEditsIfAny(HRegion.java:2811)
        at 
org.apache.hadoop.hbase.regionserver.HRegion.initializeRegionInternals(HRegion.java:583)
        at 
org.apache.hadoop.hbase.regionserver.HRegion.initialize(HRegion.java:499)
        at 
org.apache.hadoop.hbase.regionserver.HRegion.openHRegion(HRegion.java:3939)
        at 
org.apache.hadoop.hbase.regionserver.HRegion.openHRegion(HRegion.java:3887)
        at 
org.apache.hadoop.hbase.regionserver.handler.OpenRegionHandler.openRegion(OpenRegionHandler.java:332)
        at 
org.apache.hadoop.hbase.regionserver.handler.OpenRegionHandler.process(OpenRegionHandler.java:108)
        at 
org.apache.hadoop.hbase.executor.EventHandler.run(EventHandler.java:169)
        at 
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:662)
{format}



Browse the code of this part, seems a critial bug about global memstore size 
when replaying recovered edits.

(RegionServerAccounting#clearRegionReplayEditsSize is called  for each edit 
file, it means the roll back size is smaller than actual when calling 
RegionServerAccounting#rollbackRegionReplayEditsSize)

Anyway,  the solution is easy as the patch.



--
This message was sent by Atlassian JIRA
(v6.1#6144)

Reply via email to