Change default for initial block report to 0 sec and document it in hadoop-defaults.xml

• Key: HADOOP-3486
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Sanjay Radia
• Reporter: Sanjay Radia
• Fix Version/s: 0.18.0

Description

HADOOP-2326 added a new config parameter for the initial block report that gets sent after DataNode registration.
The default value for this parameter was 60 sec.

This Jira changes the default to 0 sec - the approriate default for 1 node or small clusters (say less than 50 nodes)
This Jira also documents the config parameter in hadoop-defaults.xml

Comments

[Owen O'Malley]

There is a reasonable case to be made for setting this to 0 secs in the default.

In particular, now hdfs on a single node configuration takes much much longer to come up than before.

[Sanjay Radia]

I had set the default for common mid sized cluster (100-400 nodes).
Looks like we should really do HADOOP-2444 which automates the backoff parameter.
I guess the argument is that the person running the one node cluster needs to right default value and that only one running a larger cluster is smart enough to configure the
appropriate delay parameter.

Jira description and patch has been updated to set the default to 0.

[Hairong Kuang]

+1. The change looks good.

[Hadoop QA]

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12383333/hadoopDefaults4Delay2.patch
against trunk revision 662913.

+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 patch. The patch command could not apply the patch.

Console output: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2559/console

This message is automatically generated.

[Hadoop QA]

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12383333/hadoopDefaults4Delay2.patch
against trunk revision 662976.

+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/2568/testReport/
Findbugs warnings: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2568/artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Checkstyle results: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2568/artifact/trunk/build/test/checkstyle-errors.html
Console output: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2568/console

This message is automatically generated.

[Owen O'Malley]

I just committed this. Thanks, Sanjay!