[
https://issues.apache.org/jira/browse/HBASE-13970?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14602704#comment-14602704
]
Duo Zhang commented on HBASE-13970:
-----------------------------------
No, counter can not be same for 2 threads. For a given value of counter, only
one CAS operation can succeed. The failed thread will try another round and the
value of counter will be changed.
This is the getAndIncrement methods in AtomicInteger. The only difference is
how to calculate the next value.
{code}
/**
* Atomically increments by one the current value.
*
* @return the previous value
*/
public final int getAndIncrement() {
for (;;) {
int current = get();
int next = current + 1;
if (compareAndSet(current, next))
return current;
}
}
{code}
> NPE during compaction in trunk
> ------------------------------
>
> Key: HBASE-13970
> URL: https://issues.apache.org/jira/browse/HBASE-13970
> Project: HBase
> Issue Type: Bug
> Affects Versions: 2.0.0, 0.98.13, 1.2.0, 1.1.1
> Reporter: ramkrishna.s.vasudevan
> Assignee: ramkrishna.s.vasudevan
> Fix For: 2.0.0, 0.98.14, 1.2.0, 1.1.2
>
> Attachments: HBASE-13970-v1.patch, HBASE-13970.patch
>
>
> Updated the trunk.. Loaded the table with PE tool. Trigger a flush to ensure
> all data is flushed out to disk. When the first compaction is triggered we
> get an NPE and this is very easy to reproduce
> {code}
> 015-06-25 21:33:46,041 INFO [main-EventThread]
> procedure.ZKProcedureMemberRpcs: Received procedure start children changed
> event: /hbase/flush-table-proc/acquired
> 2015-06-25 21:33:46,051 INFO
> [rs(stobdtserver3,16040,1435248182301)-flush-proc-pool3-thread-1]
> regionserver.HRegion: Flushing 1/1 column families, memstore=76.91 MB
> 2015-06-25 21:33:46,159 ERROR
> [regionserver/stobdtserver3/10.224.54.70:16040-longCompactions-1435248183945]
> regionserver.CompactSplitThread: Compaction failed Request =
> regionName=TestTable,00000000000000000000283887,1435248198798.028fb0324cd6eb03d5022eb8c147b7c4.,
> storeName=info, fileCount=3, fileSize=343.4 M (114.5 M, 114.5 M, 114.5 M),
> priority=3, time=7536968291719985
> java.lang.NullPointerException
> at
> org.apache.hadoop.hbase.regionserver.compactions.PressureAwareCompactionThroughputController$ActiveCompaction.access$700(PressureAwareCompactionThroughputController.java:79)
> at
> org.apache.hadoop.hbase.regionserver.compactions.PressureAwareCompactionThroughputController.finish(PressureAwareCompactionThroughputController.java:238)
> at
> org.apache.hadoop.hbase.regionserver.compactions.Compactor.performCompaction(Compactor.java:306)
> at
> org.apache.hadoop.hbase.regionserver.compactions.DefaultCompactor.compact(DefaultCompactor.java:106)
> at
> org.apache.hadoop.hbase.regionserver.DefaultStoreEngine$DefaultCompactionContext.compact(DefaultStoreEngine.java:112)
> at
> org.apache.hadoop.hbase.regionserver.HStore.compact(HStore.java:1202)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.compact(HRegion.java:1792)
> at
> org.apache.hadoop.hbase.regionserver.CompactSplitThread$CompactionRunner.run(CompactSplitThread.java:524)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
> at java.lang.Thread.run(Thread.java:745)
> 2015-06-25 21:33:46,745 INFO
> [rs(stobdtserver3,16040,1435248182301)-flush-proc-pool3-thread-1]
> regionserver.DefaultStoreFlusher: Flushed, sequenceid=1534, memsize=76.9 M,
> hasBloomFilter=true, into tmp file
> hdfs://stobdtserver3:9010/hbase/data/default/TestTable/028fb0324cd6eb03d5022eb8c147b7c4/.tmp/942ba0831a0047a08987439e34361a0c
> 2015-06-25 21:33:46,772 INFO
> [rs(stobdtserver3,16040,1435248182301)-flush-proc-pool3-thread-1]
> regionserver.HStore: Added
> hdfs://stobdtserver3:9010/hbase/data/default/TestTable/028fb0324cd6eb03d5022eb8c147b7c4/info/942ba0831a0047a08987439e34361a0c,
> entries=68116, sequenceid=1534, filesize=68.7 M
> 2015-06-25 21:33:46,773 INFO
> [rs(stobdtserver3,16040,1435248182301)-flush-proc-pool3-thread-1]
> regionserver.HRegion: Finished memstore flush of ~76.91 MB/80649344,
> currentsize=0 B/0 for region
> TestTable,00000000000000000000283887,1435248198798.028fb0324cd6eb03d5022eb8c147b7c4.
> in 723ms, sequenceid=1534, compaction requested=true
> 2015-06-25 21:33:46,780 INFO [main-EventThread]
> procedure.ZKProcedureMemberRpcs: Received created
> event:/hbase/flush-table-proc/reached/TestTable
> 2015-06-25 21:33:46,790 INFO [main-EventThread]
> procedure.ZKProcedureMemberRpcs: Received created
> event:/hbase/flush-table-proc/abort/TestTable
> 2015-06-25 21:33:46,791 INFO [main-EventThread]
> procedure.ZKProcedureMemberRpcs: Received procedure abort children changed
> event: /hbase/flush-table-proc/abort
> 2015-06-25 21:33:46,803 INFO [main-EventThread]
> procedure.ZKProcedureMemberRpcs: Received procedure start children changed
> event: /hbase/flush-table-proc/acquired
> 2015-06-25 21:33:46,818 INFO [main-EventThread]
> procedure.ZKProcedureMemberRpcs: Received procedure abort children changed
> event: /hbase/flush-table-proc/abort
> {code}
> Will check this on what is the reason behind it.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
