Examples with DbusEventAppender com.linkedin.databus.core.test.DbusEventAppender used on opensource projects

Example 26 with DbusEventAppender

use of com.linkedin.databus.core.test.DbusEventAppender in project databus by linkedin.

the class TestGenericDispatcher method testLargeWindowCheckpointFrequency.

@Test(groups = { "small", "functional" })
public void testLargeWindowCheckpointFrequency() throws Exception {
    final Logger log = Logger.getLogger("TestGenericDispatcher.testLargeWindowCheckpointFrequency");
    log.info("start");
    /* Consumer creation */
    int timeTakenForEventInMs = 1;
    DatabusStreamConsumer tConsumer = new TimeoutTestConsumer(timeTakenForEventInMs);
    DatabusCombinedConsumer sdccTConsumer = new SelectingDatabusCombinedConsumer(tConsumer);
    HashMap<Long, List<RegisterResponseEntry>> schemaMap = new HashMap<Long, List<RegisterResponseEntry>>();
    short srcId = 1;
    List<RegisterResponseEntry> l1 = new ArrayList<RegisterResponseEntry>();
    l1.add(new RegisterResponseEntry(1L, srcId, SOURCE1_SCHEMA_STR));
    schemaMap.put(1L, l1);
    Map<Long, IdNamePair> sourcesMap = new HashMap<Long, IdNamePair>();
    List<String> sources = new ArrayList<String>();
    for (int i = 1; i <= 1; ++i) {
        IdNamePair sourcePair = new IdNamePair((long) i, "source" + i);
        sources.add(sourcePair.getName());
        sourcesMap.put(sourcePair.getId(), sourcePair);
    }
    DatabusV2ConsumerRegistration consumerReg = new DatabusV2ConsumerRegistration(sdccTConsumer, sources, null);
    List<DatabusV2ConsumerRegistration> allRegistrations = Arrays.asList(consumerReg);
    MultiConsumerCallback mConsumer = new MultiConsumerCallback(allRegistrations, Executors.newFixedThreadPool(2), 1000, new StreamConsumerCallbackFactory(null, null), null, null, null, null);
    /* Source configuration */
    double thresholdChkptPct = 50.0;
    DatabusSourcesConnection.Config conf = new DatabusSourcesConnection.Config();
    conf.setCheckpointThresholdPct(thresholdChkptPct);
    DatabusSourcesConnection.StaticConfig connConfig = conf.build();
    /* Generate events **/
    Vector<DbusEvent> srcTestEvents = new Vector<DbusEvent>();
    Vector<Short> srcIdList = new Vector<Short>();
    srcIdList.add(srcId);
    int numEvents = 100;
    int payloadSize = 20;
    int maxWindowSize = 80;
    DbusEventGenerator evGen = new DbusEventGenerator(0, srcIdList);
    Assert.assertTrue(evGen.generateEvents(numEvents, maxWindowSize, 512, payloadSize, srcTestEvents) > 0);
    int size = 0;
    for (DbusEvent e : srcTestEvents) {
        if (!e.isControlMessage()) {
            size = e.size();
            break;
        }
    }
    // make buffer large enough to hold data
    int producerBufferSize = (int) (numEvents * size * 1.1);
    int individualBufferSize = producerBufferSize;
    int indexSize = producerBufferSize / 10;
    int stagingBufferSize = producerBufferSize;
    /*Event Buffer creation */
    final TestGenericDispatcherEventBuffer dataEventsBuffer = new TestGenericDispatcherEventBuffer(getConfig(producerBufferSize, individualBufferSize, indexSize, stagingBufferSize, AllocationPolicy.HEAP_MEMORY, QueuePolicy.BLOCK_ON_WRITE));
    List<DatabusSubscription> subs = DatabusSubscription.createSubscriptionList(sources);
    /* Generic Dispatcher creation */
    TestDispatcher<DatabusCombinedConsumer> dispatcher = new TestDispatcher<DatabusCombinedConsumer>("freqCkpt", connConfig, subs, new InMemoryPersistenceProvider(), dataEventsBuffer, mConsumer, true);
    /* Launch writer */
    DbusEventAppender eventProducer = new DbusEventAppender(srcTestEvents, dataEventsBuffer, null);
    Thread tEmitter = new Thread(eventProducer);
    tEmitter.start();
    tEmitter.join();
    /* Launch dispatcher */
    Thread tDispatcher = new Thread(dispatcher);
    tDispatcher.start();
    /* Now initialize this damn state machine */
    dispatcher.enqueueMessage(SourcesMessage.createSetSourcesIdsMessage(sourcesMap.values()));
    dispatcher.enqueueMessage(SourcesMessage.createSetSourcesSchemasMessage(schemaMap));
    Thread.sleep(2000);
    System.out.println("Number of checkpoints = " + dispatcher.getNumCheckPoints());
    Assert.assertTrue(dispatcher.getNumCheckPoints() == 3);
    dispatcher.shutdown();
    verifyNoLocks(null, dataEventsBuffer);
    log.info("end\n");
}

Example 27 with DbusEventAppender

use of com.linkedin.databus.core.test.DbusEventAppender in project databus by linkedin.

the class TestGenericDispatcher method testShutdownBeforeRollback.

@Test(groups = { "small", "functional" })
public /**
 * 1. Dispatcher is dispatching 2 window of events.
 * 2. First window consumption is successfully done.
 * 3. The second window's onStartDataEventSequence() of the callback registered is blocked (interruptible),
 *    causing the dispatcher to wait.
 * 4. At this instant the dispatcher is shut down. The callback is made to return Failure status which would
 *    cause rollback in normal scenario.
 * 5. As the shutdown message is passed, the blocked callback is expected to be interrupted and no rollback
 *    calls MUST be made.
 */
void testShutdownBeforeRollback() throws Exception {
    final Logger log = Logger.getLogger("TestGenericDispatcher.testShutdownBeforeRollback");
    log.setLevel(Level.INFO);
    // log.getRoot().setLevel(Level.DEBUG);
    LOG.info("start");
    // generate events
    Vector<Short> srcIdList = new Vector<Short>();
    srcIdList.add((short) 1);
    DbusEventGenerator evGen = new DbusEventGenerator(0, srcIdList);
    Vector<DbusEvent> srcTestEvents = new Vector<DbusEvent>();
    final int numEvents = 8;
    final int numEventsPerWindow = 4;
    final int payloadSize = 200;
    Assert.assertTrue(evGen.generateEvents(numEvents, numEventsPerWindow, 500, payloadSize, srcTestEvents) > 0);
    // find out how much data we need to stream for the failure
    // account for the EOW event which is < payload size
    int win1Size = payloadSize - 1;
    for (DbusEvent e : srcTestEvents) {
        win1Size += e.size();
    }
    // serialize the events to a buffer so they can be sent to the client
    final TestGenericDispatcherEventBuffer srcEventsBuf = new TestGenericDispatcherEventBuffer(_generic100KBufferStaticConfig);
    DbusEventAppender eventProducer = new DbusEventAppender(srcTestEvents, srcEventsBuf, null, true);
    Thread tEmitter = new Thread(eventProducer);
    tEmitter.start();
    // Create destination (client) buffer
    final TestGenericDispatcherEventBuffer destEventsBuf = new TestGenericDispatcherEventBuffer(_generic100KBufferStaticConfig);
    /**
     *  Consumer with ability to wait for latch during onStartDataEventSequence()
     */
    class TimeoutDESConsumer extends TimeoutTestConsumer {

        private final CountDownLatch latch = new CountDownLatch(1);

        private int _countStartWindow = 0;

        private final int _failedRequestNumber;

        public TimeoutDESConsumer(int failedRequestNumber) {
            super(1, 1, 0, 0, 0, 0);
            _failedRequestNumber = failedRequestNumber;
        }

        public CountDownLatch getLatch() {
            return latch;
        }

        @Override
        public ConsumerCallbackResult onStartDataEventSequence(SCN startScn) {
            _countStartWindow++;
            if (_countStartWindow == _failedRequestNumber) {
                // Wait for the latch to open
                try {
                    latch.await();
                } catch (InterruptedException e) {
                }
                return ConsumerCallbackResult.ERROR_FATAL;
            }
            return super.onStartDataEventSequence(startScn);
        }

        @Override
        public ConsumerCallbackResult onDataEvent(DbusEvent e, DbusEventDecoder eventDecoder) {
            return ConsumerCallbackResult.SUCCESS;
        }

        public int getNumBeginWindowCalls() {
            return _countStartWindow;
        }
    }
    // Create dispatcher
    // fail on second window
    final TimeoutDESConsumer mockConsumer = new TimeoutDESConsumer(2);
    SelectingDatabusCombinedConsumer sdccMockConsumer = new SelectingDatabusCombinedConsumer((DatabusStreamConsumer) mockConsumer);
    List<String> sources = new ArrayList<String>();
    Map<Long, IdNamePair> sourcesMap = new HashMap<Long, IdNamePair>();
    for (int i = 1; i <= 3; ++i) {
        IdNamePair sourcePair = new IdNamePair((long) i, "source" + i);
        sources.add(sourcePair.getName());
        sourcesMap.put(sourcePair.getId(), sourcePair);
    }
    DatabusV2ConsumerRegistration consumerReg = new DatabusV2ConsumerRegistration(sdccMockConsumer, sources, null);
    List<DatabusV2ConsumerRegistration> allRegistrations = Arrays.asList(consumerReg);
    final ConsumerCallbackStats callbackStats = new ConsumerCallbackStats(0, "test", "test", true, false, null);
    final UnifiedClientStats unifiedStats = new UnifiedClientStats(0, "test", "test.unified");
    MultiConsumerCallback callback = new MultiConsumerCallback(allRegistrations, Executors.newFixedThreadPool(2), // 100 ms budget
    100, new StreamConsumerCallbackFactory(callbackStats, unifiedStats), callbackStats, unifiedStats, null, null);
    callback.setSourceMap(sourcesMap);
    List<DatabusSubscription> subs = DatabusSubscription.createSubscriptionList(sources);
    final RelayDispatcher dispatcher = new RelayDispatcher("dispatcher", _genericRelayConnStaticConfig, subs, new InMemoryPersistenceProvider(), destEventsBuf, callback, null, null, null, null, null);
    final Thread dispatcherThread = new Thread(dispatcher);
    log.info("starting dispatcher thread");
    dispatcherThread.start();
    // Generate RegisterRespone for schema
    HashMap<Long, List<RegisterResponseEntry>> schemaMap = new HashMap<Long, List<RegisterResponseEntry>>();
    List<RegisterResponseEntry> l1 = new ArrayList<RegisterResponseEntry>();
    List<RegisterResponseEntry> l2 = new ArrayList<RegisterResponseEntry>();
    List<RegisterResponseEntry> l3 = new ArrayList<RegisterResponseEntry>();
    l1.add(new RegisterResponseEntry(1L, (short) 1, SOURCE1_SCHEMA_STR));
    l2.add(new RegisterResponseEntry(2L, (short) 1, SOURCE2_SCHEMA_STR));
    l3.add(new RegisterResponseEntry(3L, (short) 1, SOURCE3_SCHEMA_STR));
    schemaMap.put(1L, l1);
    schemaMap.put(2L, l2);
    schemaMap.put(3L, l3);
    // Enqueue Necessary messages before starting dispatch
    dispatcher.enqueueMessage(SourcesMessage.createSetSourcesIdsMessage(sourcesMap.values()));
    dispatcher.enqueueMessage(SourcesMessage.createSetSourcesSchemasMessage(schemaMap));
    log.info("starting event dispatch");
    // comm channels between reader and writer
    Pipe pipe = Pipe.open();
    Pipe.SinkChannel writerStream = pipe.sink();
    Pipe.SourceChannel readerStream = pipe.source();
    writerStream.configureBlocking(true);
    /*
       *  Needed for DbusEventBuffer.readEvents() to exit their loops when no more data is available.
       *  With Pipe mimicking ChunkedBodyReadableByteChannel, we need to make Pipe non-blocking on the
       *  reader side to achieve the behavior that ChunkedBodyReadableByte channel provides.
       */
    readerStream.configureBlocking(false);
    // Event writer - Relay in the real world
    Checkpoint cp = Checkpoint.createFlexibleCheckpoint();
    // Event readers - Clients in the real world
    // Checkpoint pullerCheckpoint = Checkpoint.createFlexibleCheckpoint();
    DbusEventsStatisticsCollector clientStats = new DbusEventsStatisticsCollector(0, "client", true, false, null);
    DbusEventBufferReader reader = new DbusEventBufferReader(destEventsBuf, readerStream, null, clientStats);
    UncaughtExceptionTrackingThread tReader = new UncaughtExceptionTrackingThread(reader, "Reader");
    tReader.setDaemon(true);
    tReader.start();
    try {
        log.info("send both windows");
        StreamEventsResult streamRes = srcEventsBuf.streamEvents(cp, writerStream, new StreamEventsArgs(win1Size));
        // EOP events, presumably?
        Assert.assertEquals(// EOP events, presumably?
        "num events streamed should equal total number of events plus 2", numEvents + 2, streamRes.getNumEventsStreamed());
        TestUtil.assertWithBackoff(new ConditionCheck() {

            @Override
            public boolean check() {
                return 2 == mockConsumer.getNumBeginWindowCalls();
            }
        }, "second window processing started", 5000, log);
        dispatcher.shutdown();
        // remove the barrier
        mockConsumer.getLatch().countDown();
        TestUtil.assertWithBackoff(new ConditionCheck() {

            @Override
            public boolean check() {
                return !dispatcherThread.isAlive();
            }
        }, "Ensure Dispatcher thread is shutdown", 5000, log);
        TestUtil.assertWithBackoff(new ConditionCheck() {

            @Override
            public boolean check() {
                return 0 == mockConsumer.getNumRollbacks();
            }
        }, "Ensure No Rollback is called", 10, log);
    } finally {
        reader.stop();
    }
    log.info("end\n");
}

Example 28 with DbusEventAppender

use of com.linkedin.databus.core.test.DbusEventAppender in project databus by linkedin.

the class TestGenericDispatcher method runDispatcherRollback.

/**
 * @param numEvents  number of events that will be written out in the test
 * @param maxWindowSize  size of window expressed as #events
 * @param numFailDataEvent  the nth data event at which failure occurs; 0 == no failures
 * @param numFailCheckpointEvent  the nth checkpoint event at which failure occurs; 0 == no failures
 * @param numFailEndWindow  the nth end-of-window at which failure occurs; 0 == no failures
 * @param thresholdPct  checkpointThresholdPct - forcible checkpoint before end-of-window
 * @param negativeTest  is this test supposed to fail
 * @param numFailures  number of failures expected (across all error types); in effect controls number of rollbacks
 * @param bootstrapCheckpointsPerWindow  k bootstrap checkpoint events are written for every one end-of-window event
 * @param timeTakenForDataEventInMs  time taken for processing data events
 * @param timeTakenForControlEventInMs  time taken for processing control events
 * @param wrapAround  use a smaller producer buffer so that events will wrap around
 */
protected void runDispatcherRollback(int numEvents, int maxWindowSize, int numFailDataEvent, int numFailCheckpointEvent, int numFailEndWindow, double thresholdPct, boolean negativeTest, int numFailures, int bootstrapCheckpointsPerWindow, long timeTakenForDataEventInMs, long timeTakenForControlEventInMs, boolean wrapAround) throws Exception {
    LOG.info("Running dispatcher rollback with: " + "numEvents=" + numEvents + " maxWindowSize=" + maxWindowSize + " numFailDataEvent=" + numFailDataEvent + " numFailCheckpoint=" + numFailCheckpointEvent + " numFailEndWindow=" + numFailEndWindow + " thresholdPct=" + thresholdPct + " negativeTest=" + negativeTest + " numFailures=" + numFailures + " bootstrapCheckpointsPerWindow=" + bootstrapCheckpointsPerWindow + " timeTakenForDataEventsInMs=" + timeTakenForDataEventInMs + " timeTakenForControlEventsInMs=" + timeTakenForControlEventInMs + " wrapAround=" + wrapAround);
    /* Experiment setup */
    int payloadSize = 20;
    int numCheckpoints = numEvents / maxWindowSize;
    /* Consumer creation */
    // set up consumer to fail on data callback at the nth event
    TimeoutTestConsumer tConsumer = new TimeoutTestConsumer(timeTakenForDataEventInMs, timeTakenForControlEventInMs, numFailCheckpointEvent, numFailDataEvent, numFailEndWindow, numFailures);
    HashMap<Long, List<RegisterResponseEntry>> schemaMap = new HashMap<Long, List<RegisterResponseEntry>>();
    short srcId = 1;
    List<RegisterResponseEntry> l1 = new ArrayList<RegisterResponseEntry>();
    l1.add(new RegisterResponseEntry(1L, srcId, SOURCE1_SCHEMA_STR));
    schemaMap.put(1L, l1);
    Map<Long, IdNamePair> sourcesMap = new HashMap<Long, IdNamePair>();
    List<String> sources = new ArrayList<String>();
    for (int i = 1; i <= 1; ++i) {
        IdNamePair sourcePair = new IdNamePair((long) i, "source" + i);
        sources.add(sourcePair.getName());
        sourcesMap.put(sourcePair.getId(), sourcePair);
    }
    long consumerTimeBudgetMs = 60 * 1000;
    DatabusV2ConsumerRegistration consumerReg = new DatabusV2ConsumerRegistration(tConsumer, sources, null);
    List<DatabusV2ConsumerRegistration> allRegistrations = Arrays.asList(consumerReg);
    final UnifiedClientStats unifiedStats = new UnifiedClientStats(0, "test", "test.unified");
    // single-threaded execution of consumer
    MultiConsumerCallback mConsumer = new MultiConsumerCallback(allRegistrations, Executors.newFixedThreadPool(1), consumerTimeBudgetMs, new StreamConsumerCallbackFactory(null, unifiedStats), null, unifiedStats, null, null);
    /* Generate events */
    Vector<DbusEvent> srcTestEvents = new Vector<DbusEvent>();
    Vector<Short> srcIdList = new Vector<Short>();
    srcIdList.add(srcId);
    DbusEventGenerator evGen = new DbusEventGenerator(0, srcIdList);
    Assert.assertTrue(evGen.generateEvents(numEvents, maxWindowSize, 512, payloadSize, srcTestEvents) > 0);
    int totalSize = 0;
    int maxSize = 0;
    for (DbusEvent e : srcTestEvents) {
        totalSize += e.size();
        maxSize = (e.size() > maxSize) ? e.size() : maxSize;
    }
    /* Source configuration */
    double thresholdChkptPct = thresholdPct;
    DatabusSourcesConnection.Config conf = new DatabusSourcesConnection.Config();
    conf.setCheckpointThresholdPct(thresholdChkptPct);
    conf.getDispatcherRetries().setMaxRetryNum(10);
    conf.setFreeBufferThreshold(maxSize);
    conf.setConsumerTimeBudgetMs(consumerTimeBudgetMs);
    int freeBufferThreshold = conf.getFreeBufferThreshold();
    DatabusSourcesConnection.StaticConfig connConfig = conf.build();
    // make buffer large enough to hold data; the control events are large that contain checkpoints
    int producerBufferSize = wrapAround ? totalSize : totalSize * 2 + numCheckpoints * 10 * maxSize * 5 + freeBufferThreshold;
    int individualBufferSize = producerBufferSize;
    int indexSize = producerBufferSize / 10;
    int stagingBufferSize = producerBufferSize;
    /* Event Buffer creation */
    TestGenericDispatcherEventBuffer dataEventsBuffer = new TestGenericDispatcherEventBuffer(getConfig(producerBufferSize, individualBufferSize, indexSize, stagingBufferSize, AllocationPolicy.HEAP_MEMORY, QueuePolicy.BLOCK_ON_WRITE));
    List<DatabusSubscription> subs = DatabusSubscription.createSubscriptionList(sources);
    /* Generic Dispatcher creation */
    TestDispatcher<DatabusCombinedConsumer> dispatcher = new TestDispatcher<DatabusCombinedConsumer>("rollBackcheck", connConfig, subs, new InMemoryPersistenceProvider(), dataEventsBuffer, mConsumer, bootstrapCheckpointsPerWindow == 0);
    /* Launch writer */
    DbusEventAppender eventProducer = new DbusEventAppender(srcTestEvents, dataEventsBuffer, bootstrapCheckpointsPerWindow, null);
    Thread tEmitter = new Thread(eventProducer);
    tEmitter.start();
    /* Launch dispatcher */
    Thread tDispatcher = new Thread(dispatcher);
    tDispatcher.start();
    /* Now initialize this state machine */
    dispatcher.enqueueMessage(SourcesMessage.createSetSourcesIdsMessage(sourcesMap.values()));
    dispatcher.enqueueMessage(SourcesMessage.createSetSourcesSchemasMessage(schemaMap));
    // be generous; use worst case for num control events
    long waitTimeMs = (numEvents * timeTakenForDataEventInMs + numEvents * timeTakenForControlEventInMs) * 4;
    tEmitter.join(waitTimeMs);
    // wait for dispatcher to finish reading the events
    tDispatcher.join(waitTimeMs);
    Assert.assertFalse(tEmitter.isAlive());
    System.out.println("tConsumer: " + tConsumer);
    int windowBeforeDataFail = (numFailDataEvent / maxWindowSize);
    int expectedDataFaults = numFailDataEvent == 0 ? 0 : numFailures;
    int expectedCheckPointFaults = (numFailCheckpointEvent == 0 || (expectedDataFaults != 0 && numFailCheckpointEvent == windowBeforeDataFail)) ? 0 : numFailures;
    // check if all windows were logged by dispatcher; in online case;
    if (bootstrapCheckpointsPerWindow == 0) {
        Assert.assertTrue(dispatcher.getNumCheckPoints() >= (numCheckpoints - expectedCheckPointFaults));
    }
    // Consumer prespective
    // 1 or 0 faults  injected in data callbacks; success (store) differs callback by 1
    Assert.assertEquals("Mismatch between callbacks and stored data on consumer.", expectedDataFaults, tConsumer.getDataCallbackCount() - tConsumer.getStoredDataCount());
    Assert.assertTrue(tConsumer.getStoredDataCount() >= tConsumer.getNumUniqStoredEvents());
    Assert.assertEquals("Consumer failed to store expected number of checkpoints.", dispatcher.getNumCheckPoints(), tConsumer.getStoredCheckpointCount());
    // it's converted to ConsumerCallbackResult.SKIP_CHECKPOINT and therefore not seen by client metrics.
    if (expectedCheckPointFaults == 0 || expectedDataFaults > 0 || negativeTest) {
        Assert.assertTrue("Unexpected error count in consumer metrics (" + unifiedStats.getNumConsumerErrors() + "); should be greater than or equal to numFailures (" + numFailures + ").", unifiedStats.getNumConsumerErrors() >= numFailures);
    } else {
        Assert.assertEquals("Unexpected error count in consumer metrics; checkpoint errors shouldn't count. ", // unless negativeTest ...
        0, unifiedStats.getNumConsumerErrors());
    }
    // rollback behaviour; were all events re-sent?
    if (!negativeTest) {
        Assert.assertTrue(tConsumer.getNumUniqStoredEvents() == numEvents);
    } else {
        Assert.assertTrue(tConsumer.getNumUniqStoredEvents() < numEvents);
    }
    dispatcher.shutdown();
    verifyNoLocks(null, dataEventsBuffer);
}

Example 29 with DbusEventAppender

use of com.linkedin.databus.core.test.DbusEventAppender in project databus by linkedin.

the class TestGenericDispatcher method testControlEventsRemoval.

@Test(groups = { "small", "functional" })
public void testControlEventsRemoval() throws Exception {
    final Logger log = Logger.getLogger("TestGenericDispatcher.testControlEventsRemoval");
    log.info("start");
    // DDSDBUS-559
    /* Consumer creation */
    int timeTakenForEventInMs = 10;
    TimeoutTestConsumer tConsumer = new TimeoutTestConsumer(timeTakenForEventInMs);
    HashMap<Long, List<RegisterResponseEntry>> schemaMap = new HashMap<Long, List<RegisterResponseEntry>>();
    short srcId = 1;
    List<RegisterResponseEntry> l1 = new ArrayList<RegisterResponseEntry>();
    l1.add(new RegisterResponseEntry(1L, srcId, SOURCE1_SCHEMA_STR));
    schemaMap.put(1L, l1);
    Map<Long, IdNamePair> sourcesMap = new HashMap<Long, IdNamePair>();
    List<String> sources = new ArrayList<String>();
    for (int i = 1; i <= 1; ++i) {
        IdNamePair sourcePair = new IdNamePair((long) i, "source" + i);
        sources.add(sourcePair.getName());
        sourcesMap.put(sourcePair.getId(), sourcePair);
    }
    DatabusV2ConsumerRegistration consumerReg = new DatabusV2ConsumerRegistration(tConsumer, sources, null);
    List<DatabusV2ConsumerRegistration> allRegistrations = Arrays.asList(consumerReg);
    MultiConsumerCallback mConsumer = new MultiConsumerCallback(allRegistrations, Executors.newFixedThreadPool(2), 1000, new StreamConsumerCallbackFactory(null, null), null, null, null, null);
    /* Source configuration */
    double thresholdChkptPct = 10.0;
    DatabusSourcesConnection.Config conf = new DatabusSourcesConnection.Config();
    conf.setCheckpointThresholdPct(thresholdChkptPct);
    int freeBufferThreshold = conf.getFreeBufferThreshold();
    DatabusSourcesConnection.StaticConfig connConfig = conf.build();
    /* Generate events **/
    Vector<DbusEvent> srcTestEvents = new Vector<DbusEvent>();
    Vector<Short> srcIdList = new Vector<Short>();
    srcIdList.add(srcId);
    int numEvents = 100;
    int payloadSize = 20;
    int maxWindowSize = 1;
    DbusEventGenerator evGen = new DbusEventGenerator(0, srcIdList);
    Assert.assertTrue(evGen.generateEvents(numEvents, maxWindowSize, payloadSize + 62, payloadSize, srcTestEvents) > 0);
    long lastWindowScn = srcTestEvents.get(srcTestEvents.size() - 1).sequence();
    int size = 0;
    for (DbusEvent e : srcTestEvents) {
        if (e.size() > size)
            size = e.size();
    }
    // make buffer large enough to hold data
    int numWindows = (numEvents / maxWindowSize) + 1;
    int producerBufferSize = (numEvents + numWindows) * size + freeBufferThreshold;
    int individualBufferSize = producerBufferSize;
    int indexSize = producerBufferSize / 10;
    int stagingBufferSize = producerBufferSize;
    /*Event Buffer creation */
    final TestGenericDispatcherEventBuffer dataEventsBuffer = new TestGenericDispatcherEventBuffer(getConfig(producerBufferSize, individualBufferSize, indexSize, stagingBufferSize, AllocationPolicy.HEAP_MEMORY, QueuePolicy.BLOCK_ON_WRITE));
    List<DatabusSubscription> subs = DatabusSubscription.createSubscriptionList(sources);
    /* Generic Dispatcher creation */
    TestDispatcher<DatabusCombinedConsumer> dispatcher = new TestDispatcher<DatabusCombinedConsumer>("freqCkpt", connConfig, subs, new InMemoryPersistenceProvider(), dataEventsBuffer, mConsumer, true);
    /* Launch writer */
    /* write events all of which  are empty windows */
    DbusEventAppender eventProducer = new DbusEventAppender(srcTestEvents, dataEventsBuffer, null, 1.0, true, 0);
    Thread tEmitter = new Thread(eventProducer);
    tEmitter.start();
    tEmitter.join();
    long freeSpaceBefore = dataEventsBuffer.getBufferFreeSpace();
    /* Launch dispatcher */
    Thread tDispatcher = new Thread(dispatcher);
    tDispatcher.start();
    /* Now initialize  state machine */
    dispatcher.enqueueMessage(SourcesMessage.createSetSourcesIdsMessage(sourcesMap.values()));
    dispatcher.enqueueMessage(SourcesMessage.createSetSourcesSchemasMessage(schemaMap));
    tDispatcher.join(5000);
    LOG.warn("Free Space After=" + dataEventsBuffer.getBufferFreeSpace() + " tConsumer=" + tConsumer + " expected last window=" + lastWindowScn + " last Window = " + dataEventsBuffer.lastWrittenScn());
    Assert.assertTrue(dataEventsBuffer.lastWrittenScn() == lastWindowScn);
    Assert.assertTrue(freeSpaceBefore < dataEventsBuffer.getBufferFreeSpace());
    dispatcher.shutdown();
    verifyNoLocks(null, dataEventsBuffer);
    log.info("end\n");
}