[HDFS-11353] Improve the unit tests relevant to DataNode volume failure testing

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0-alpha2
• Fix Version/s: 3.0.0-alpha4
• Target Version/s: 3.0.0-alpha4
• Hadoop Flags: Reviewed
• Assignee: Yiqun Lin
• Reporter: Yiqun Lin
• Created: 20/Jan/17 12:36
• Updated: 08/Feb/17 11:03
• Resolved: 02/Feb/17 11:42

Description

Currently there are many tests which start with TestDataNodeVolumeFailure* frequently run timedout or failed. I found one failure test in recent Jenkins building. The stack info:

org.apache.hadoop.hdfs.server.datanode.TestDataNodeVolumeFailureReporting.testSuccessiveVolumeFailures
java.util.concurrent.TimeoutException: Timed out waiting for DN to die
	at org.apache.hadoop.hdfs.DFSTestUtil.waitForDatanodeDeath(DFSTestUtil.java:702)
	at org.apache.hadoop.hdfs.server.datanode.TestDataNodeVolumeFailureReporting.testSuccessiveVolumeFailures(TestDataNodeVolumeFailureReporting.java:208)

The related codes:

    /*
     * Now fail the 2nd volume on the 3rd datanode. All its volumes
     * are now failed and so it should report two volume failures
     * and that it's no longer up. Only wait for two replicas since
     * we'll never get a third.
     */
    DataNodeTestUtils.injectDataDirFailure(dn3Vol2);
    Path file3 = new Path("/test3");
    DFSTestUtil.createFile(fs, file3, 1024, (short)3, 1L);
    DFSTestUtil.waitReplication(fs, file3, (short)2);

    // The DN should consider itself dead
    DFSTestUtil.waitForDatanodeDeath(dns.get(2));

Here the code waits for the datanode failed all the volume and then become dead. But it timed out. We would be better to compare that if all the volumes are failed then wair for the datanode dead.

In addition, we can use the method checkDiskErrorSync to do the disk error check instead of creaing files. In this JIRA, I would like to extract this logic and defined that in DataNodeTestUtils. And then we can reuse this method for datanode volme failure testing in the future.

Issue Links

• is duplicated by: HDFS-11372 Increase test timeouts that are too aggressive.