At least one evidence of possible race condition has been seen in the Hudson build
Integrated in Hdfs-Patch-h2.grid.sp2.yahoo.net #81 (See http://hudson.zones.apache.org/hudson/job/Hdfs-Patch-h2.grid.sp2.yahoo.net/81/)
Integrated in Hdfs-Patch-h5.grid.sp2.yahoo.net #118 (See http://hudson.zones.apache.org/hudson/job/Hdfs-Patch-h5.grid.sp2.yahoo.net/118/)
Integrated in Hadoop-Hdfs-trunk #145 (See http://hudson.zones.apache.org/hudson/job/Hadoop-Hdfs-trunk/145/)
Integrated in Hadoop-Hdfs-trunk-Commit #112 (See http://hudson.zones.apache.org/hudson/job/Hadoop-Hdfs-trunk-Commit/112/)
. Intermittent race condition in TestFiPipelines. Contributed by Konstantin Boudnik
Thanks for the review, Nicholas.
The patch affects branch 0.21 as well.
I've just committed this.
+1 overall. Here are the results of testing the latest attachment
against trunk revision 880630.
+1 @author. The patch does not contain any @author tags.
+1 tests included. The patch appears to include 3 new or modified tests.
+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/Hdfs-Patch-h2.grid.sp2.yahoo.net/76/testReport/
Findbugs warnings: http://hudson.zones.apache.org/hudson/job/Hdfs-Patch-h2.grid.sp2.yahoo.net/76/artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Checkstyle results: http://hudson.zones.apache.org/hudson/job/Hdfs-Patch-h2.grid.sp2.yahoo.net/76/artifact/trunk/build/test/checkstyle-errors.html
Console output: http://hudson.zones.apache.org/hudson/job/Hdfs-Patch-h2.grid.sp2.yahoo.net/76/console
This message is automatically generated.
I've ran the patched code a number of times and it seems to be Ok.
Making shutdown() method to be synchronized should address the issue
The issue is seems to be caused by a concurrent attempt to shutdown mini cluster.