The jobtracker could log the detailed reason string in blacklistTracker when it logs the task tracker change to blacklisted/graylisted state. Currently it logs the shade (black or gray) and the ReasonForBlackListing. The reason string is already passed into the function so we can just add it to the log message calls.

log message now:
INFO org.apache.hadoop.mapred.JobTracker: Adding new blacklisted tracker : XXX Reason for blacklisting is : NODE_UNHEALTHY

Would become something like:
INFO org.apache.hadoop.mapred.JobTracker: Adding new blacklisted tracker : XXX Reason for blacklisting is : NODE_UNHEALTHY Reason details : Error string returned from healthChecker.script

For the 20.205 branch these are based on branch-0.20-security here are the results of test-patch. The -1 for javadoc and eclipse both exists in the branch-20-security without my change.

I didn't include any tests because this is a trivial change to the log message. Manual test steps are below.

[exec] -1 overall.
[exec]
[exec] +1 @author. The patch does not contain any @author tags.
[exec]
[exec] -1 tests included. The patch doesn't appear to include any new or modified tests.
[exec] Please justify why no tests are needed for this patch.
[exec]
[exec] -1 javadoc. The javadoc tool appears to have generated 1 warning messages.
[exec]
[exec] +1 javac. The applied patch does not increase the total number of javac compiler warnings.
[exec] [exec] +1 findbugs. The patch does not introduce any new Findbugs warnings. [exec]
[exec] -1 Eclipse classpath. The patch causes the Eclipse classpath to differ from the contents of the lib directories. [exec] [exec]
[exec]
[exec]

Manual test steps:

• modify mapred_site.xml to have the mapred.healthChecker.script.path configuration. Have it point to a script like ~/health_check.
• modify ~/health_check to contain just something like:
  #!/bin/bash
  exit 0

• start the cluster and make sure every is running fine.
• modify the ~/health_check script on a tasktracker and insert the a line like: echo -n "ERROR new string" before the exit 0 line.
• wait for tasktracker to send heartbeat back with updated health info
• look in the jobtracker log file and verify the log line looks similar to this. This bug added the "Reason details : ERROR new string" bit.
  2011-05-04 13:30:31,926 INFO org.apache.hadoop.mapred.JobTracker: Blacklisting tracker : yourhost.com Reason for blacklisting is : NODE_UNHEALTHY Reason details : ERROR new string
• also verify the tasktracker got blacklisted.

Attaching trunk patch again to see if hudson build will start

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12478596/MAPREDUCE-2451-trunk.patch
against trunk revision 1100409.

+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 new tests are needed for this patch.
Also please list what manual steps were performed to verify 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 (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 core unit tests:
org.apache.hadoop.mapred.TestDebugScript

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

+1 system test framework. The patch passed system test framework compile.

Test results: https://builds.apache.org/hudson/job/PreCommit-MAPREDUCE-Build/225//testReport/
Findbugs warnings: https://builds.apache.org/hudson/job/PreCommit-MAPREDUCE-Build/225//artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Console output: https://builds.apache.org/hudson/job/PreCommit-MAPREDUCE-Build/225//console

This message is automatically generated.

The TestDebugScript test runs fine when I run it manually:

[junit] Running org.apache.hadoop.mapred.TestDebugScript
[junit] Tests run: 1, Failures: 0, Errors: 0, Time elapsed: 7.571 sec

+1

I committed this. Thanks, Tom!

Integrated in Hadoop-Mapreduce-trunk-Commit #660 (See https://builds.apache.org/hudson/job/Hadoop-Mapreduce-trunk-Commit/660/)
MAPREDUCE-2451. Log the details from health check script at the
JobTracker. Contributed by Thomas Graves

Integrated in Hadoop-Mapreduce-trunk #675 (See https://builds.apache.org/hudson/job/Hadoop-Mapreduce-trunk/675/)
MAPREDUCE-2451. Log the details from health check script at the
JobTracker. Contributed by Thomas Graves

Hadoop 0.20.204.0 was just released.