@Test
public void testStateTransition()
throws InterruptedException, ExecutionException, TimeoutException {
InMemoryZKServer zkServer = InMemoryZKServer.builder().build();
zkServer.startAndWait();
try {
final String namespace =
Joiner.on('/').join("/twill", RunIds.generate(), "runnables", "Runner1");
final ZKClientService zkClient =
ZKClientService.Builder.of(zkServer.getConnectionStr()).build();
zkClient.startAndWait();
zkClient.create(namespace, null, CreateMode.PERSISTENT).get();
try {
JsonObject content = new JsonObject();
content.addProperty("containerId", "container-123");
content.addProperty("host", "localhost");
RunId runId = RunIds.generate();
final Semaphore semaphore = new Semaphore(0);
ZKServiceDecorator service =
new ZKServiceDecorator(
ZKClients.namespace(zkClient, namespace),
runId,
Suppliers.ofInstance(content),
new AbstractIdleService() {
@Override
protected void startUp() throws Exception {
Preconditions.checkArgument(
semaphore.tryAcquire(5, TimeUnit.SECONDS), "Fail to start");
}
@Override
protected void shutDown() throws Exception {
Preconditions.checkArgument(
semaphore.tryAcquire(5, TimeUnit.SECONDS), "Fail to stop");
}
});
final String runnablePath = namespace + "/" + runId.getId();
final AtomicReference<String> stateMatch = new AtomicReference<String>("STARTING");
watchDataChange(zkClient, runnablePath + "/state", semaphore, stateMatch);
Assert.assertEquals(Service.State.RUNNING, service.start().get(5, TimeUnit.SECONDS));
stateMatch.set("STOPPING");
Assert.assertEquals(Service.State.TERMINATED, service.stop().get(5, TimeUnit.SECONDS));
} finally {
zkClient.stopAndWait();
}
} finally {
zkServer.stopAndWait();
}
}
private static ZKClient getContainerZKClient(
ZKClient zkClient, RunId appRunId, String runnableName) {
return ZKClients.namespace(zkClient, String.format("/%s/runnables/%s", appRunId, runnableName));
}
/** Returns a {@link ZKClient} that namespaced under the given run id. */
private static ZKClient getAppRunZKClient(ZKClient zkClient, RunId appRunId) {
return ZKClients.namespace(zkClient, String.format("/%s", appRunId));
}