testTickTupleWorksWithSystemBolt Time elapsed: 6.802 s <<< FAILURE!
java.lang.AssertionError: Iteration 1 expected:<52000> but was:<51000>
The test runs a topology in a local cluster with time simulation. One of the bolts has tick tuples enabled, and the test tries to check that the ticks arrive with 1 second intervals.
As far as I can tell, the problem is that time simulation doesn't cover the bolt and spout executors. When the test increases simulated time by 1 second and waits for the cluster to idle, the test expects that to mean that the bolt will at that point have consumed the tick. In some cases this doesn't happen, and multiple tick tuples may end up queued before the bolt consumes them. Since the bolt is responsible for generating the timestamp, the test will fail.