[MAPREDUCE-5136] TestJobImpl->testJobNoTasks fails with IBM JAVA

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.3-alpha
• Fix Version/s: 2.1.0-beta

Environment

Linux + IBM JAVA 6

• Target Version/s: 2.1.0-beta
• Hadoop Flags: Reviewed
• Assignee: Amir F Sanjar
• Reporter: Amir F Sanjar
• Created: 07/Apr/13 05:23
• Updated: 27/Aug/13 22:22
• Resolved: 11/Apr/13 19:19

Description

I am not sure if this is a testcase or a design issue. During execution of TestJobImpl->testJobNoTasks() there is an assertion made based on the order of key/value pairs stored in adjacency list. However adjacency list was created by Configuration->getValByRegex() as a HashMap (order is not guaranteed):

Testcase:
JobSubmittedEventHandler jseHandler = new JobSubmittedEventHandler("testId",
"testName", "testNodeName", "\"key2\"=\"value2\" \"key1\"=\"value1\" ");
....
....
try {
Assert.assertTrue(jseHandler.getAssertValue()); <===

Configuration->getValByRegex():
public Map<String,String> getValByRegex(String regex) {
Pattern p = Pattern.compile(regex);
Map<String,String> result = new HashMap<String,String>(); <=======

as we all know, HashMap makes absolutely no guarantees about the iteration order. It can (and will) even change completely when new elements are added.

Changing HashMap to LinkedHashMap fixes the ordering inconsistency, however with a small performance side effect.