TestResourceTracker.backgroundTestStarted(this) doesn't work from the IDE

When running from an IDE, UnitTestTestNGListener doesn't (usually) run, so the current test name isn't set on the main thread. (TestResourceTracker.getCurrentTestName() returns "main").

Calling TestResourceTracker.backgroundTestStarted() on a worker thread sets the proper test name, and because of TEST_PING, the cache managers started from the main thread and the worker thread can't join the same cluster.