[HDFS-4669] TestBlockPoolManager fails using IBM java

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.3-alpha
• Fix Version/s: 2.1.0-beta
• Component/s: test
• Labels: patch
• Target Version/s: 2.1.0-beta
• Hadoop Flags: Reviewed
• Assignee: Tian Hong Wang
• Reporter: Tian Hong Wang
• Created: 08/Apr/13 13:34
• Updated: 27/Aug/13 22:08
• Resolved: 09/Apr/13 19:07

Description

TestBlockPoolManager unit test fails with the following error message using IBM java:
testFederationRefresh(org.apache.hadoop.hdfs.server.datanode.TestBlockPoolManager) Time elapsed: 27 sec <<< FAILURE!
org.junit.ComparisonFailure: expected:<stop #[1
refresh #2]
> but was:<stop #[2
refresh #1]
>

The root cause is:
(1)if we want to remove the first NS, keep the second NS, it should be conf.set(DFSConfigKeys.DFS_NAMESERVICES, ns2), not conf.set(DFSConfigKeys.DFS_NAMESERVICES, ns1).

(2)Since HashMap & HashSet store the data in the random order way, so in ibm java & Oracle java, HashMap get the random order <key, value> that causing the random ns1&ns2 value. So in the code, it should use LinkedHashMap & LinkedHashSet to keep the original order.