[ 
https://issues.apache.org/jira/browse/HBASE-6311?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13406881#comment-13406881
 ] 

Hadoop QA commented on HBASE-6311:
----------------------------------

-1 overall.  Here are the results of testing the latest attachment 
  http://issues.apache.org/jira/secure/attachment/12535148/HBASE-6311v2.patch
  against trunk revision .

    +1 @author.  The patch does not contain any @author tags.

    +1 tests included.  The patch appears to include 4 new or modified tests.

    +1 hadoop2.0.  The patch compiles against the hadoop 2.0 profile.

    +1 javadoc.  The javadoc tool did not generate any warning messages.

    -1 javac.  The applied patch generated 5 javac compiler warnings (more than 
the trunk's current 4 warnings).

    -1 findbugs.  The patch appears to introduce 7 new Findbugs (version 1.3.9) 
warnings.

    +1 release audit.  The applied patch does not increase the total number of 
release audit warnings.

     -1 core tests.  The patch failed these unit tests:
                       org.apache.hadoop.hbase.regionserver.TestAtomicOperation
                  org.apache.hadoop.hbase.replication.TestReplication

Test results: 
https://builds.apache.org/job/PreCommit-HBASE-Build/2325//testReport/
Findbugs warnings: 
https://builds.apache.org/job/PreCommit-HBASE-Build/2325//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-common.html
Findbugs warnings: 
https://builds.apache.org/job/PreCommit-HBASE-Build/2325//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-server.html
Console output: 
https://builds.apache.org/job/PreCommit-HBASE-Build/2325//console

This message is automatically generated.
                
> Data error after majorCompaction caused by keeping MVCC for opened scanners
> ---------------------------------------------------------------------------
>
>                 Key: HBASE-6311
>                 URL: https://issues.apache.org/jira/browse/HBASE-6311
>             Project: HBase
>          Issue Type: Bug
>          Components: regionserver
>    Affects Versions: 0.94.0
>            Reporter: chunhui shen
>            Assignee: chunhui shen
>            Priority: Blocker
>             Fix For: 0.96.0, 0.94.1
>
>         Attachments: HBASE-6311-test.patch, HBASE-6311v1.patch, 
> HBASE-6311v2.patch
>
>
> It is a big problem we found in 0.94, and you could reproduce the problem in 
> Trunk using the test case I uploaded.
> When we do compaction, we will use region.getSmallestReadPoint() to keep MVCC 
> for opened scanners;
> However,It will make data mistake after majorCompaction because we will skip 
> delete type KV but keep the put type kv in the compacted storefile.
> The following is the reason from code:
> In StoreFileScanner, enforceMVCC is false when compaction, so we could read 
> the delete type KV,
> However, we will skip this delete type KV in ScanQueryMatcher because 
> following code
> {code}
> if (kv.isDelete())
> {
> ...
>  if (includeDeleteMarker
>             && kv.getMemstoreTS() <= maxReadPointToTrackVersions) {
>           System.out.println("add deletes,maxReadPointToTrackVersions="
>               + maxReadPointToTrackVersions);
>           this.deletes.add(bytes, offset, qualLength, timestamp, type);
>         }
> ...
> }
> {code}
> Here maxReadPointToTrackVersions = region.getSmallestReadPoint();
> and kv.getMemstoreTS() > maxReadPointToTrackVersions 
> So we won't add this to DeleteTracker.
> Why test case passed if remove the line 
> MultiVersionConsistencyControl.setThreadReadPoint(smallestReadPoint);
> Because in the StoreFileScanner#skipKVsNewerThanReadpoint
> {code}
> if (cur.getMemstoreTS() <= readPoint) {
>       cur.setMemstoreTS(0);
>     }
> {code}
> So if we remove the line 
> MultiVersionConsistencyControl.setThreadReadPoint(smallestReadPoint);
> Here readPoint is LONG.MAX_VALUE, we will set memStore ts as 0, so we will 
> add it to DeleteTracker in ScanQueryMatcher 
> Solution:
> We use smallestReadPoint of region when compaction to keep MVCC for OPENED 
> scanner, So we should retain delete type kv in output in the case(Already 
> deleted KV is retained in output to make old opened scanner could read this 
> KV) even if it is a majorcompaction.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: 
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Reply via email to