*tl;dr**: invoke this method in the VM in which you're going to create
your locator*
Rolling upgrade tests that want to ensure that old locator state files
have been deleted are using this method incorrectly.
It's very common to see a rolling upgrade test delete old locator state
files during setup. You'll see something like this:
int locatorPort = AvailablePort.getRandomAvailablePort();
DistributedTestUtils.deleteLocatorStateFile(locatorPort);
This keeps old files created by previously run tests from infecting this
test. However, this use of the method doesn't work.
The problem is that DUnitLauncher runs each VM in its own directory.
Deleting a file in the current working directory of the VM driving the
test won't find a file in your locator's working directory. You've got
to delete that file in the context of the process you're going to use to
host the locator.
VM locatorVM = Host.getHost(0).getVM(oldVersion, 0);
int port = AvailablePortHelper.getRandomAvailablePort();
* locatorVM.invoke("delete state file", () ->
*DistributedTestUtils.deleteLocatorStateFile(locatorPort)*);*
