The timeout on TestUnnecessaryBlockingOnHistoryFileInfo.testTwoThreadsQueryingDifferentJobOfSameUser is added to verify the fix of
MAPREDUCE-6684 works. When two thread are requesting different jobs owned by the same user, one thread request jobA should not be blocked by the other that is processing a large job jobB. The timeout exception, if happened, should ideally indicate the fix does not work. But the timeout period is set too aggressive, so the test always fails on slow VMs.