DatanodeDescriptor objects stored in FSImage may be out dated.

• Key: HADOOP-3329
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: dhruba borthakur
• Reporter: Tsz Wo (Nicholas), SZE
• Fix Version/s: 0.18.0

Description

INodeFileUnderConstruction.targets is a DatanodeDescriptor array which stores the locations for last block. These DatanodeDescriptors are serialized and stored in the FSImage. However, a DatanodeDescriptor contains information like IP address and ports. These information may be out dated after a datanode restart.

We should probably only stored the storageID of a DatanodeDescriptor in FSImage and then lookup the DatanodeDescriptor object from the datanodeMap.

Comments

[dhruba borthakur]

I think it is worthwhile to not store the DatanodeDescriptor in the fsimage at all. The "append" code needs the location of the last block of the file to do lease recovery. In the case when the namenode restarts and before it does lease recovery, it will get the block locations of the last block from datanodes as part of block reports.

[dhruba borthakur]

This patch removes the last block locations that were earlier stored in each persistent lease record.

[Hadoop QA]

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12381486/lastBlockLocations.patch
against trunk revision 653749.

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

-1 tests included. The patch doesn't appear to include any new or modified tests.
Please justify why no tests are needed for this patch.

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

+1 javac. The applied patch does not increase the total number of javac compiler warnings.

+1 findbugs. The patch does not introduce any new Findbugs warnings.

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

+1 core tests. The patch passed core unit tests.

+1 contrib tests. The patch passed contrib unit tests.

Test results: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2411/testReport/
Findbugs warnings: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2411/artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Checkstyle results: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2411/artifact/trunk/build/test/checkstyle-errors.html
Console output: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2411/console

This message is automatically generated.

[Tsz Wo (Nicholas), SZE]

+1 codes look good

[dhruba borthakur]

I just committed this.

[Hudson]

Integrated in Hadoop-trunk #486 (See http://hudson.zones.apache.org/hudson/job/Hadoop-trunk/486/)