Examples with StateListener org.apache.kafka.streams.KafkaStreams.StateListener used on opensource projects

Example 1 with StateListener

use of org.apache.kafka.streams.KafkaStreams.StateListener in project kafka by apache.

the class IntegrationTestUtils method startApplicationAndWaitUntilRunning.

/**
 * Starts the given {@link KafkaStreams} instances and waits for all of them to reach the
 * {@link State#RUNNING} state at the same time. Note that states may change between the time
 * that this method returns and the calling function executes its next statement.<p>
 *
 * If the application is already started, use {@link #waitForApplicationState(List, State, Duration)}
 * to wait for instances to reach {@link State#RUNNING} state.
 *
 * @param streamsList the list of streams instances to run.
 * @param timeout the time to wait for the streams to all be in {@link State#RUNNING} state.
 */
public static void startApplicationAndWaitUntilRunning(final List<KafkaStreams> streamsList, final Duration timeout) throws Exception {
    final Lock stateLock = new ReentrantLock();
    final Condition stateUpdate = stateLock.newCondition();
    final Map<KafkaStreams, State> stateMap = new HashMap<>();
    for (final KafkaStreams streams : streamsList) {
        stateMap.put(streams, streams.state());
        final StateListener prevStateListener = getStateListener(streams);
        final StateListener newStateListener = (newState, oldState) -> {
            stateLock.lock();
            try {
                stateMap.put(streams, newState);
                if (newState == State.RUNNING) {
                    if (stateMap.values().stream().allMatch(state -> state == State.RUNNING)) {
                        stateUpdate.signalAll();
                    }
                }
            } finally {
                stateLock.unlock();
            }
        };
        streams.setStateListener(prevStateListener != null ? new CompositeStateListener(prevStateListener, newStateListener) : newStateListener);
    }
    for (final KafkaStreams streams : streamsList) {
        streams.start();
    }
    final long expectedEnd = System.currentTimeMillis() + timeout.toMillis();
    stateLock.lock();
    try {
        // timeout has expired
        while (true) {
            final Map<KafkaStreams, State> nonRunningStreams = new HashMap<>();
            for (final Entry<KafkaStreams, State> entry : stateMap.entrySet()) {
                if (entry.getValue() != State.RUNNING) {
                    nonRunningStreams.put(entry.getKey(), entry.getValue());
                }
            }
            if (nonRunningStreams.isEmpty()) {
                return;
            }
            final long millisRemaining = expectedEnd - System.currentTimeMillis();
            if (millisRemaining <= 0) {
                fail("Application did not reach a RUNNING state for all streams instances. " + "Non-running instances: " + nonRunningStreams);
            }
            stateUpdate.await(millisRemaining, TimeUnit.MILLISECONDS);
        }
    } finally {
        stateLock.unlock();
    }
}

Example 2 with StateListener

use of org.apache.kafka.streams.KafkaStreams.StateListener in project kafka by apache.

the class IntegrationTestUtils method getStateListener.

private static StateListener getStateListener(final KafkaStreams streams) {
    try {
        if (streams instanceof KafkaStreamsNamedTopologyWrapper) {
            final Field field = streams.getClass().getSuperclass().getDeclaredField("stateListener");
            field.setAccessible(true);
            return (StateListener) field.get(streams);
        } else {
            final Field field = streams.getClass().getDeclaredField("stateListener");
            field.setAccessible(true);
            return (StateListener) field.get(streams);
        }
    } catch (final IllegalAccessException | NoSuchFieldException e) {
        throw new RuntimeException("Failed to get StateListener through reflection", e);
    }
}