The test *org.apache.hadoop.mapred.TestClientRedirect.testRedirect* is not idempotent and fail if run twice in the same JVM, because it pollutes some states shared among tests. It may be good to clean this state pollution so that some other tests do not fail in the future due to the shared state polluted by this test.
Running TestClientRedirect.testRedirect twice would result in the second run failing due to the following assertion error:
The root cause is that the RM server listening on port 8054) is started in the first run of this test, but hasn't been stopped when the test finishes. In the second run, when the test is trying to start the RMService, it fails because port 8054 is already in use, leading to the exception.