private void sendRemoteFragments(DrillbitEndpoint assignment, Collection<PlanFragment> fragments, CountDownLatch latch){
InitializeFragments.Builder fb = InitializeFragments.newBuilder();
for(PlanFragment f : fragments){
fb.addFragment(f);
}
InitializeFragments initFrags = fb.build();
logger.debug("Sending remote fragments to node {} with data {}", assignment, initFrags);
FragmentSubmitListener listener = new FragmentSubmitListener(assignment, initFrags, latch);
controller.getTunnel(assignment).sendFragments(listener, initFrags);
}