Load test framework doesn't use pagination when calling instanceGroupManagers.listManagedInstances

[matt-kwong]

pubsub/load-test-framework/src/main/java/com/google/pubsub/flic/controllers/resource_controllers/GCEComputeResourceController.java

Lines 240 to 264 in dced135

	InstanceGroupManagersListManagedInstancesResponse response;
	while (true) {
	try {
	response =
	compute
	.instanceGroupManagers()
	.listManagedInstances(project, params.getZone(), instanceName())
	.execute();
	} catch (GoogleJsonResponseException e) {
	log.warn("Unable to fetch response: ", e);
	continue;
	}
	if (response != null) {
	if (response.getManagedInstances() != null) {
	if (response.getManagedInstances().stream()
	.allMatch(i -> "RUNNING".equals(i.getInstanceStatus()))) {
	break;
	}
	}
	}
	log.warn("Instances not yet ready: " + (response == null ? "null" : response));
	Thread.sleep(10000);
	}

By default, instanceGroupManagers.listManagedInstances returns 500 results. If someone were to run the load test framework with publisher workers + subscriber workers > 500, then it's possible for the load test to start without all GCE instances ready to run (there's probably other issues as well).

This is probably not a big deal unless users are trying to run very expensive load tests with this framework.