The replication tests invoke Runtime.exec() directly in order to spawn processes. The sub-processes that run on the same host as the main test process, should instead be started with the helper method BaseTestCase.execJavaCmd(). Having all the tests use the helper method would make it easier if we for example want to pass specific flags to all sub-processes created in a test run.
Note that the replication tests also have code for starting processes on a remote host via ssh. BaseTestCase.execJavaCmd() cannot do that, so only local processes can be started with the helper method. When the replication tests run as part of suites.All, all the spawned processes run locally.