With the commit of HADOOP-8755, we now have support for printing a thread
dump whenever a test case times out. However, this will only happen for
test cases which are annotated with a JUnit timeout, i.e. those annotated
with something like "@Test(timeout=X)". Unfortunately, there doesn't seem
to be an easy way to add a default JUnit timeout for all of our tests, so
some tests may time out by reaching the Surefire fork timeout, in which
case the thread dump will not be printed. You can see more discussion about
this on HADOOP-8755.
So, if you see a test case fail by reaching the Surefire fork timeout,
please file a JIRA to add a JUnit timeout for that test. If when adding a
test case you think that it might time out, please add a JUnit timeout.
Aaron T. Myers
Software Engineer, Cloudera