To test some of the changes for
IMPALA-1599, it would be good to test the following case:
A query runs. One fragment is delayed at the start of Prepare(). A cancellation request comes in . Does the fragment eventually get cancelled? Is that true for the coordinator as well?
We can do this with debug actions, but we need to make the tests check if there are any fragments left in flight after cancellation has finished and the node has had time to quiesce.
IMPALA-1599 will introduce a metric that we can check to see how many fragments are still running.