getRollingUpgradeStatus doesn't have to take FSNamesystem's read lock.

Also fix the unit test so that any new metrics will be covered automatically.

The patch looks good to me. +1 (non-binding) pending Jenkins.

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12672609/HDFS-7182.patch
against trunk revision 29f5200.

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

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

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

+1 javadoc. There were no new javadoc warning messages.

+1 eclipse:eclipse. The patch built with eclipse:eclipse.

-1 findbugs. The patch appears to introduce 1 new Findbugs (version 2.0.3) 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 in hadoop-hdfs-project/hadoop-hdfs:

org.apache.hadoop.hdfs.server.namenode.TestEditLogRace
org.apache.hadoop.hdfs.TestEncryptionZonesWithKMS
org.apache.hadoop.hdfs.TestCrcCorruption
org.apache.hadoop.hdfs.server.namenode.ha.TestPipelinesFailover

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

Test results: https://builds.apache.org/job/PreCommit-HDFS-Build/8302//testReport/
Findbugs warnings: https://builds.apache.org/job/PreCommit-HDFS-Build/8302//artifact/patchprocess/newPatchFindbugsWarningshadoop-hdfs.html
Console output: https://builds.apache.org/job/PreCommit-HDFS-Build/8302//console

This message is automatically generated.

Thanks, Akira.

Findbugs and failed unit tests aren't related.

Anyone else has suggestions on this? The patch has been running fine in one of our production clusters.

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12672609/HDFS-7182.patch
against trunk revision 0402bad.

-1 patch. The patch command could not apply the patch.

Console output: https://builds.apache.org/job/PreCommit-HDFS-Build/9083//console

This message is automatically generated.

Rebased for trunk. Appreciate any input.

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12688194/HDFS-7182-2.patch
against trunk revision efe6357.

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

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

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

+1 javadoc. There were no new javadoc warning messages.

+1 eclipse:eclipse. The patch built with eclipse:eclipse.

-1 findbugs. The patch appears to introduce 1 new Findbugs (version 2.0.3) 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 in hadoop-hdfs-project/hadoop-hdfs:

org.apache.hadoop.fs.TestSymlinkHdfsFileContext
org.apache.hadoop.hdfs.server.namenode.ha.TestRetryCacheWithHA
org.apache.hadoop.hdfs.server.datanode.TestDataNodeVolumeFailureToleration

Test results: https://builds.apache.org/job/PreCommit-HDFS-Build/9085//testReport/
Findbugs warnings: https://builds.apache.org/job/PreCommit-HDFS-Build/9085//artifact/patchprocess/newPatchFindbugsWarningshadoop-hdfs.html
Console output: https://builds.apache.org/job/PreCommit-HDFS-Build/9085//console

This message is automatically generated.

The test errors are known issues, https://issues.apache.org/jira/browse/HADOOP-11432, https://issues.apache.org/jira/browse/HDFS-7524 and https://issues.apache.org/jira/browse/HDFS-7552.

+1

Currently we check if rollingUpgradeInfo is null to determine if rolling upgrade is in process. Without the read lock do we need to declare the object as volatile to make sure the jmx returns the correct result?

Good catch. Thanks, Jing. Here is the updated patch.

Thanks Ming! +1 pending Jenkins.

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12691404/HDFS-7182-3.patch
against trunk revision ae91b13.

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

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

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

+1 javadoc. There were no new javadoc warning messages.

+1 eclipse:eclipse. The patch built with eclipse:eclipse.

+1 findbugs. The patch does not introduce any new Findbugs (version 2.0.3) 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 in hadoop-hdfs-project/hadoop-hdfs:

org.apache.hadoop.hdfs.TestParallelShortCircuitReadUnCached

Test results: https://builds.apache.org/job/PreCommit-HDFS-Build/9171//testReport/
Console output: https://builds.apache.org/job/PreCommit-HDFS-Build/9171//console

This message is automatically generated.

Thanks for the contribution, Ming Ma! I've committed this to trunk and branch-2.

FAILURE: Integrated in Hadoop-trunk-Commit #6838 (See https://builds.apache.org/job/Hadoop-trunk-Commit/6838/)
HDFS-7182. JMX metrics aren't accessible when NN is busy. Contributed by Ming Ma. (jing9: rev 2a06101e61f2f7a08913c2367d9dbefb910e64a7)

• hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
• hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSNamesystemMBean.java
• hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

Thanks, Jing and Akira!

FAILURE: Integrated in Hadoop-Yarn-trunk-Java8 #69 (See https://builds.apache.org/job/Hadoop-Yarn-trunk-Java8/69/)
HDFS-7182. JMX metrics aren't accessible when NN is busy. Contributed by Ming Ma. (jing9: rev 2a06101e61f2f7a08913c2367d9dbefb910e64a7)

• hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
• hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSNamesystemMBean.java
• hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

FAILURE: Integrated in Hadoop-Yarn-trunk #803 (See https://builds.apache.org/job/Hadoop-Yarn-trunk/803/)
HDFS-7182. JMX metrics aren't accessible when NN is busy. Contributed by Ming Ma. (jing9: rev 2a06101e61f2f7a08913c2367d9dbefb910e64a7)

• hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
• hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSNamesystemMBean.java
• hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

SUCCESS: Integrated in Hadoop-Hdfs-trunk #2001 (See https://builds.apache.org/job/Hadoop-Hdfs-trunk/2001/)
HDFS-7182. JMX metrics aren't accessible when NN is busy. Contributed by Ming Ma. (jing9: rev 2a06101e61f2f7a08913c2367d9dbefb910e64a7)

• hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSNamesystemMBean.java
• hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
• hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

SUCCESS: Integrated in Hadoop-Hdfs-trunk-Java8 #66 (See https://builds.apache.org/job/Hadoop-Hdfs-trunk-Java8/66/)
HDFS-7182. JMX metrics aren't accessible when NN is busy. Contributed by Ming Ma. (jing9: rev 2a06101e61f2f7a08913c2367d9dbefb910e64a7)

• hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSNamesystemMBean.java
• hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
• hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

FAILURE: Integrated in Hadoop-Mapreduce-trunk-Java8 #70 (See https://builds.apache.org/job/Hadoop-Mapreduce-trunk-Java8/70/)
HDFS-7182. JMX metrics aren't accessible when NN is busy. Contributed by Ming Ma. (jing9: rev 2a06101e61f2f7a08913c2367d9dbefb910e64a7)

• hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSNamesystemMBean.java
• hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
• hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

SUCCESS: Integrated in Hadoop-Mapreduce-trunk #2020 (See https://builds.apache.org/job/Hadoop-Mapreduce-trunk/2020/)
HDFS-7182. JMX metrics aren't accessible when NN is busy. Contributed by Ming Ma. (jing9: rev 2a06101e61f2f7a08913c2367d9dbefb910e64a7)

• hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSNamesystemMBean.java
• hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
• hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

Sangjin Lee backported this to 2.6.1, after fixing a merge-conflict in TestFSNamesystemMBean. I just pushed the commit after running compilation and TestFSNamesystemMBean which changed in the patch.