Java Code Examples for org.apache.samza.system.kafka.descriptors.KafkaSystemDescriptor#getOutputDescriptor()

@Override
public void describe(TaskApplicationDescriptor appDescriptor) {
    Thread demoSource = new DemoKafkaProducer(INPUT_DESCRIPTOR_NAME);
    demoSource.start();
    KafkaSystemDescriptor ksd = new KafkaSystemDescriptor(SYSTEM_DESCRIPTOR_NAME)
            .withConsumerZkConnect(KAFKA_CONSUMER_ZK_CONNECT)
            .withProducerBootstrapServers(KAFKA_PRODUCER_BOOTSTRAP_SERVERS)
            .withDefaultStreamConfigs(KAFKA_DEFAULT_STREAM_CONFIGS);
    KafkaInputDescriptor kid = ksd.getInputDescriptor(INPUT_DESCRIPTOR_NAME, KVSerde.of(new IntegerSerde(), new IntegerSerde()));
    KafkaOutputDescriptor kod = ksd.getOutputDescriptor(OUTPUT_DESCRIPTOR_NAME, KVSerde.of(new IntegerSerde(), new IntegerSerde()));

    appDescriptor
            .withInputStream(kid)
            .withOutputStream(kod);

    appDescriptor.withTaskFactory(new DemoTaskFactory(SYSTEM_DESCRIPTOR_NAME, OUTPUT_DESCRIPTOR_NAME));

}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  KafkaSystemDescriptor trackingSystem = new KafkaSystemDescriptor("tracking");

  KafkaInputDescriptor<PageViewEvent> inputStreamDescriptor =
      trackingSystem.getInputDescriptor("pageViewEvent", new JsonSerdeV2<>(PageViewEvent.class));

  KafkaOutputDescriptor<KV<String, StatsOutput>> outputStreamDescriptor =
      trackingSystem.getOutputDescriptor("pageViewEventPerMember",
          KVSerde.of(new StringSerde(), new JsonSerdeV2<>(StatsOutput.class)));

  appDescriptor.withDefaultSystem(trackingSystem);
  MessageStream<PageViewEvent> pageViewEvents = appDescriptor.getInputStream(inputStreamDescriptor);
  OutputStream<KV<String, StatsOutput>> pageViewEventPerMember = appDescriptor.getOutputStream(outputStreamDescriptor);

  pageViewEvents
      .partitionBy(pve -> pve.getMemberId(), pve -> pve,
          KVSerde.of(new StringSerde(), new JsonSerdeV2<>(PageViewEvent.class)), "partitionBy")
      .map(KV::getValue)
      .flatMap(new MyStatsCounter())
      .map(stats -> KV.of(stats.memberId, stats))
      .sendTo(pageViewEventPerMember);
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  KafkaSystemDescriptor trackingSystem = new KafkaSystemDescriptor("tracking");

  KafkaInputDescriptor<PageViewEvent> inputStreamDescriptor =
      trackingSystem.getInputDescriptor("pageViewEvent", new JsonSerdeV2<>(PageViewEvent.class));

  KafkaOutputDescriptor<KV<String, PageViewCount>> outputStreamDescriptor =
      trackingSystem.getOutputDescriptor("pageViewEventPerMember",
          KVSerde.of(new StringSerde(), new JsonSerdeV2<>(PageViewCount.class)));

  MessageStream<PageViewEvent> pageViewEvents = appDescriptor.getInputStream(inputStreamDescriptor);
  OutputStream<KV<String, PageViewCount>> pageViewEventPerMemberStream = appDescriptor.getOutputStream(outputStreamDescriptor);

  SupplierFunction<Integer> initialValue = () -> 0;
  FoldLeftFunction<PageViewEvent, Integer> foldLeftFn = (m, c) -> c + 1;
  pageViewEvents
      .window(Windows.keyedTumblingWindow(PageViewEvent::getMemberId, Duration.ofSeconds(10), initialValue, foldLeftFn, null, null)
          .setEarlyTrigger(Triggers.repeat(Triggers.count(5)))
          .setAccumulationMode(AccumulationMode.DISCARDING), "tumblingWindow")
      .map(windowPane -> KV.of(windowPane.getKey().getKey(), buildPageViewCount(windowPane)))
      .sendTo(pageViewEventPerMemberStream);
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  KVSerde<String, PageViewEvent> serde = KVSerde.of(new StringSerde("UTF-8"), new JsonSerdeV2<>(PageViewEvent.class));
  KafkaSystemDescriptor trackingSystem = new KafkaSystemDescriptor("tracking");

  KafkaInputDescriptor<KV<String, PageViewEvent>> isd1 =
      trackingSystem.getInputDescriptor("pageViewStream1", serde);
  KafkaInputDescriptor<KV<String, PageViewEvent>> isd2 =
      trackingSystem.getInputDescriptor("pageViewStream2", serde);
  KafkaInputDescriptor<KV<String, PageViewEvent>> isd3 =
      trackingSystem.getInputDescriptor("pageViewStream3", serde);

  KafkaOutputDescriptor<KV<String, PageViewEvent>> osd =
      trackingSystem.getOutputDescriptor("mergedStream", serde);

  MessageStream
      .mergeAll(ImmutableList.of(appDescriptor.getInputStream(isd1), appDescriptor.getInputStream(isd2), appDescriptor.getInputStream(isd3)))
      .sendTo(appDescriptor.getOutputStream(osd));
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  KVSerde<String, PageViewEvent> serde = KVSerde.of(new StringSerde("UTF-8"), new JsonSerdeV2<>(PageViewEvent.class));
  KafkaSystemDescriptor trackingSystem = new KafkaSystemDescriptor("tracking");
  KafkaInputDescriptor<KV<String, PageViewEvent>> pageViewEvent =
      trackingSystem.getInputDescriptor("pageViewEvent", serde);
  KafkaOutputDescriptor<KV<String, PageViewEvent>> outStream1 =
      trackingSystem.getOutputDescriptor("outStream1", serde);
  KafkaOutputDescriptor<KV<String, PageViewEvent>> outStream2 =
      trackingSystem.getOutputDescriptor("outStream2", serde);
  KafkaOutputDescriptor<KV<String, PageViewEvent>> outStream3 =
      trackingSystem.getOutputDescriptor("outStream3", serde);

  MessageStream<KV<String, PageViewEvent>> inputStream = appDescriptor.getInputStream(pageViewEvent);
  inputStream.filter(m -> m.key.equals("key1")).sendTo(appDescriptor.getOutputStream(outStream1));
  inputStream.filter(m -> m.key.equals("key2")).sendTo(appDescriptor.getOutputStream(outStream2));
  inputStream.filter(m -> m.key.equals("key3")).sendTo(appDescriptor.getOutputStream(outStream3));
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  Config config = appDescriptor.getConfig();
  KafkaSystemDescriptor kafkaSystemDescriptor = new KafkaSystemDescriptor(TEST_SYSTEM);
  KafkaOutputDescriptor<PageView>
      outputDescriptor = kafkaSystemDescriptor.getOutputDescriptor(NON_GUEST_PAGE_VIEW_STREAM, new NoOpSerde<>());
  OutputStream<PageView> nonGuestPageViewStream = appDescriptor.getOutputStream(outputDescriptor);

  Predicate<PageView> failProcess = (Predicate<PageView> & Serializable) (ignored) -> config.getBoolean(FAIL_PROCESS, false);
  Predicate<PageView> failDownstreamOperator = (Predicate<PageView> & Serializable) (ignored) -> config.getBoolean(FAIL_DOWNSTREAM_OPERATOR, false);
  Supplier<Long> processJitter = (Supplier<Long> & Serializable) () -> config.getLong(PROCESS_JITTER, 100);

  appDescriptor.getInputStream(kafkaSystemDescriptor.getInputDescriptor(PAGE_VIEW_STREAM, new NoOpSerde<PageView>()))
      .flatMapAsync(pageView -> filterGuestPageViews(pageView, failProcess, processJitter))
      .filter(pageView -> filterLoginPageViews(pageView, failDownstreamOperator))
      .sendTo(nonGuestPageViewStream);
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  KafkaSystemDescriptor trackingSystem = new KafkaSystemDescriptor("tracking");

  KafkaInputDescriptor<AdClickEvent> inputStreamDescriptor =
      trackingSystem.getInputDescriptor("adClickEvent", new JsonSerdeV2<>(AdClickEvent.class));

  KafkaOutputDescriptor<KV<String, EnrichedAdClickEvent>> outputStreamDescriptor =
      trackingSystem.getOutputDescriptor("enrichedAdClickEvent",
          KVSerde.of(new StringSerde(), new JsonSerdeV2<>(EnrichedAdClickEvent.class)));

  MessageStream<AdClickEvent> adClickEventStream = appDescriptor.getInputStream(inputStreamDescriptor);
  OutputStream<KV<String, EnrichedAdClickEvent>> enrichedAdClickStream =
      appDescriptor.getOutputStream(outputStreamDescriptor);

  adClickEventStream
      .flatMapAsync(AsyncApplicationExample::enrichAdClickEvent)
      .map(enrichedAdClickEvent -> KV.of(enrichedAdClickEvent.getCountry(), enrichedAdClickEvent))
      .sendTo(enrichedAdClickStream);
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  KVSerde<String, PageView> inputSerde = KVSerde.of(new StringSerde("UTF-8"), new JsonSerdeV2<>(PageView.class));
  KVSerde<String, String> outputSerde = KVSerde.of(new StringSerde(), new StringSerde());
  KafkaSystemDescriptor ksd = new KafkaSystemDescriptor(SYSTEM);
  KafkaInputDescriptor<KV<String, PageView>> id = ksd.getInputDescriptor(INPUT_TOPIC, inputSerde);
  KafkaOutputDescriptor<KV<String, String>> od = ksd.getOutputDescriptor(OUTPUT_TOPIC, outputSerde);

  appDescriptor.getInputStream(id)
      .map(KV::getValue)
      .partitionBy(PageView::getUserId, m -> m, inputSerde, "p1")
      .window(Windows.keyedSessionWindow(m -> m.getKey(), Duration.ofSeconds(3), () -> 0, (m, c) -> c + 1, new StringSerde("UTF-8"), new IntegerSerde()), "w1")
      .map(wp -> KV.of(wp.getKey().getKey().toString(), String.valueOf(wp.getMessage())))
      .sendTo(appDescriptor.getOutputStream(od));

}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  JsonSerdeV2<PageView> inputSerde = new JsonSerdeV2<>(PageView.class);
  KVSerde<String, Integer> outputSerde = KVSerde.of(new StringSerde(), new IntegerSerde());
  KafkaSystemDescriptor ksd = new KafkaSystemDescriptor(SYSTEM);
  KafkaInputDescriptor<PageView> id = ksd.getInputDescriptor(INPUT_TOPIC, inputSerde);
  KafkaOutputDescriptor<KV<String, Integer>> od = ksd.getOutputDescriptor(OUTPUT_TOPIC, outputSerde);

  MessageStream<PageView> pageViews = appDescriptor.getInputStream(id);
  OutputStream<KV<String, Integer>> outputStream = appDescriptor.getOutputStream(od);

  pageViews
      .filter(m -> !FILTER_KEY.equals(m.getUserId()))
      .window(Windows.keyedSessionWindow(PageView::getUserId, Duration.ofSeconds(3),
          new StringSerde(), new JsonSerdeV2<>(PageView.class)), "sessionWindow")
      .map(m -> KV.of(m.getKey().getKey(), m.getMessage().size()))
      .sendTo(outputStream);
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  JsonSerdeV2<PageView> inputSerde = new JsonSerdeV2<>(PageView.class);
  KVSerde<String, Integer> outputSerde = KVSerde.of(new StringSerde(), new IntegerSerde());
  KafkaSystemDescriptor ksd = new KafkaSystemDescriptor(SYSTEM);
  KafkaInputDescriptor<PageView> id = ksd.getInputDescriptor(INPUT_TOPIC, inputSerde);
  KafkaOutputDescriptor<KV<String, Integer>> od = ksd.getOutputDescriptor(OUTPUT_TOPIC, outputSerde);

  MessageStream<PageView> pageViews = appDescriptor.getInputStream(id);
  OutputStream<KV<String, Integer>> outputStream = appDescriptor.getOutputStream(od);

  pageViews
      .filter(m -> !FILTER_KEY.equals(m.getUserId()))
      .window(Windows.keyedTumblingWindow(PageView::getUserId, Duration.ofSeconds(3),
          new StringSerde(), new JsonSerdeV2<>(PageView.class)), "tumblingWindow")
      .map(m -> KV.of(m.getKey().getKey(), m.getMessage().size()))
      .sendTo(outputStream);

}
 

@Override
public void describe(TaskApplicationDescriptor appDescriptor) {
  KafkaSystemDescriptor ksd = new KafkaSystemDescriptor("test");
  KafkaInputDescriptor<Profile> profileISD = ksd.getInputDescriptor("Profile", new JsonSerdeV2<>());
  KafkaInputDescriptor<PageView> pageViewISD = ksd.getInputDescriptor("PageView", new JsonSerdeV2<>());
  KafkaOutputDescriptor<EnrichedPageView> enrichedPageViewOSD =
      ksd.getOutputDescriptor("EnrichedPageView", new NoOpSerde<>());
  appDescriptor
      .withInputStream(profileISD)
      .withInputStream(pageViewISD)
      .withOutputStream(enrichedPageViewOSD)
      .withTable(new InMemoryTableDescriptor("profile-view-store",
          KVSerde.of(new IntegerSerde(), new TestTableData.ProfileJsonSerde())))
      .withTaskFactory((StreamTaskFactory) () -> new StatefulStreamTask());
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  Table<KV<Integer, TestTableData.Profile>> table = appDescriptor.getTable(
      new RocksDbTableDescriptor<Integer, TestTableData.Profile>("profile-view-store",
          KVSerde.of(new IntegerSerde(), new TestTableData.ProfileJsonSerde())));

  KafkaSystemDescriptor ksd = new KafkaSystemDescriptor("test");

  KafkaInputDescriptor<KV<String, TestTableData.Profile>> profileISD =
      ksd.getInputDescriptor("Profile", KVSerde.of(new StringSerde(), new JsonSerdeV2<>()));

  KafkaInputDescriptor<KV<String, TestTableData.PageView>> pageViewISD =
      ksd.getInputDescriptor("PageView", KVSerde.of(new StringSerde(), new JsonSerdeV2<>()));
  KafkaOutputDescriptor<TestTableData.EnrichedPageView> enrichedPageViewOSD =
      ksd.getOutputDescriptor("EnrichedPageView", new JsonSerdeV2<>());

  appDescriptor.getInputStream(profileISD)
      .map(m -> new KV(m.getValue().getMemberId(), m.getValue()))
      .sendTo(table)
      .sink((kv, collector, coordinator) -> {
        LOG.info("Inserted Profile with Key: {} in profile-view-store", kv.getKey());
      });

  OutputStream<TestTableData.EnrichedPageView> outputStream = appDescriptor.getOutputStream(enrichedPageViewOSD);
  appDescriptor.getInputStream(pageViewISD)
      .partitionBy(pv -> pv.getValue().getMemberId(),  pv -> pv.getValue(), KVSerde.of(new IntegerSerde(), new JsonSerdeV2<>(TestTableData.PageView.class)), "p1")
      .join(table, new PageViewToProfileJoinFunction())
      .sendTo(outputStream)
      .map(TestTableData.EnrichedPageView::getPageKey)
      .sink((joinPageKey, collector, coordinator) -> {
        collector.send(new OutgoingMessageEnvelope(new SystemStream("test", "JoinPageKeys"), null, null, joinPageKey));
      });

}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  KafkaSystemDescriptor ksd = new KafkaSystemDescriptor(systemName);
  KafkaOutputDescriptor<String> osd = ksd.getOutputDescriptor(outputTopic, new StringSerde());
  OutputStream<String> outputStream = appDescriptor.getOutputStream(osd);

  for (String inputTopic : inputTopics) {
    KafkaInputDescriptor<String> isd = ksd.getInputDescriptor(inputTopic, new NoOpSerde<>());
    MessageStream<String> inputStream = appDescriptor.getInputStream(isd);
    inputStream.map(new TestMapFunction(appName, processorName)).sendTo(outputStream);
  }
}
 

@Override
public void describe(TaskApplicationDescriptor appDescriptor) {
  KafkaSystemDescriptor ksd = new KafkaSystemDescriptor(systemName);
  KafkaInputDescriptor<TestTableData.Profile> inputDescriptor = ksd.getInputDescriptor(inputTopic, new NoOpSerde<>());
  KafkaOutputDescriptor<TestTableData.EnrichedPageView> outputDescriptor = ksd.getOutputDescriptor(outputTopic, new NoOpSerde<>());
  appDescriptor.withInputStream(inputDescriptor)
               .withOutputStream(outputDescriptor)
               .withTaskFactory((AsyncStreamTaskFactory) () -> new TestTaskImpl());
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  String systemName = "testSystemName";
  String inputStreamName = appDescriptor.getConfig().get("input.stream.name");
  String outputStreamName = "standaloneIntegrationTestKafkaOutputTopic";
  LOGGER.info("Publishing message from: {} to: {}.", inputStreamName, outputStreamName);
  KafkaSystemDescriptor kafkaSystemDescriptor = new KafkaSystemDescriptor(systemName);

  KVSerde<Object, Object> noOpSerde = KVSerde.of(new NoOpSerde<>(), new NoOpSerde<>());
  KafkaInputDescriptor<KV<Object, Object>> isd =
      kafkaSystemDescriptor.getInputDescriptor(inputStreamName, noOpSerde);
  KafkaOutputDescriptor<KV<Object, Object>> osd =
      kafkaSystemDescriptor.getOutputDescriptor(outputStreamName, noOpSerde);
  appDescriptor.getInputStream(isd).sendTo(appDescriptor.getOutputStream(osd));
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  KafkaSystemDescriptor kafkaSystemDescriptor = new KafkaSystemDescriptor(KAFKA_SYSTEM_NAME)
      .withConsumerZkConnect(KAFKA_CONSUMER_ZK_CONNECT)
      .withProducerBootstrapServers(KAFKA_PRODUCER_BOOTSTRAP_SERVERS)
      .withDefaultStreamConfigs(KAFKA_DEFAULT_STREAM_CONFIGS);

  KafkaInputDescriptor<String> stockSymbolInputDescriptor =
      kafkaSystemDescriptor.getInputDescriptor(INPUT_STREAM_ID, new StringSerde());
  KafkaOutputDescriptor<StockPrice> stockPriceOutputDescriptor =
      kafkaSystemDescriptor.getOutputDescriptor(OUTPUT_STREAM_ID, new JsonSerdeV2<>(StockPrice.class));
  appDescriptor.withDefaultSystem(kafkaSystemDescriptor);
  MessageStream<String> stockSymbolStream = appDescriptor.getInputStream(stockSymbolInputDescriptor);
  OutputStream<StockPrice> stockPriceStream = appDescriptor.getOutputStream(stockPriceOutputDescriptor);

  RemoteTableDescriptor<String, Double> remoteTableDescriptor =
      new RemoteTableDescriptor("remote-table")
          .withReadRateLimit(10)
          .withReadFunction(new StockPriceReadFunction());
  CachingTableDescriptor<String, Double> cachedRemoteTableDescriptor =
      new CachingTableDescriptor<>("cached-remote-table", remoteTableDescriptor)
          .withReadTtl(Duration.ofSeconds(5));
  Table<KV<String, Double>> cachedRemoteTable = appDescriptor.getTable(cachedRemoteTableDescriptor);

  stockSymbolStream
      .map(symbol -> new KV<String, Void>(symbol, null))
      .join(cachedRemoteTable, new JoinFn())
      .sendTo(stockPriceStream);

}
 

@Override
public void describe(TaskApplicationDescriptor taskApplicationDescriptor) {

  // Define a system descriptor for Kafka, which is both our input and output system
  KafkaSystemDescriptor kafkaSystemDescriptor =
      new KafkaSystemDescriptor("kafka").withConsumerZkConnect(KAFKA_CONSUMER_ZK_CONNECT)
          .withProducerBootstrapServers(KAFKA_PRODUCER_BOOTSTRAP_SERVERS)
          .withDefaultStreamConfigs(KAFKA_DEFAULT_STREAM_CONFIGS);

  // Input descriptor for the wikipedia-raw topic
  KafkaInputDescriptor kafkaInputDescriptor =
      kafkaSystemDescriptor.getInputDescriptor("wikipedia-raw", new JsonSerde<>());

  // Output descriptor for the wikipedia-edits topic
  KafkaOutputDescriptor kafkaOutputDescriptor =
      kafkaSystemDescriptor.getOutputDescriptor("wikipedia-edits", new JsonSerde<>());

  // Set the default system descriptor to Kafka, so that it is used for all
  // internal resources, e.g., kafka topic for checkpointing, coordinator stream.
  taskApplicationDescriptor.withDefaultSystem(kafkaSystemDescriptor);

  // Set the input
  taskApplicationDescriptor.withInputStream(kafkaInputDescriptor);

  // Set the output
  taskApplicationDescriptor.withOutputStream(kafkaOutputDescriptor);

  // Set the task factory
  taskApplicationDescriptor.withTaskFactory((StreamTaskFactory) () -> new WikipediaParserStreamTask());
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
  Serde<Profile> profileSerde = new JsonSerdeV2<>(Profile.class);
  Serde<PageView> pageViewSerde = new JsonSerdeV2<>(PageView.class);
  Serde<EnrichedPageView> joinResultSerde = new JsonSerdeV2<>(EnrichedPageView.class);

  KafkaSystemDescriptor kafkaSystemDescriptor = new KafkaSystemDescriptor(KAFKA_SYSTEM_NAME)
      .withConsumerZkConnect(KAFKA_CONSUMER_ZK_CONNECT)
      .withProducerBootstrapServers(KAFKA_PRODUCER_BOOTSTRAP_SERVERS)
      .withDefaultStreamConfigs(KAFKA_DEFAULT_STREAM_CONFIGS);

  KafkaInputDescriptor<Profile> profileInputDescriptor =
      kafkaSystemDescriptor.getInputDescriptor(PROFILE_STREAM_ID, profileSerde);
  KafkaInputDescriptor<PageView> pageViewInputDescriptor =
      kafkaSystemDescriptor.getInputDescriptor(PAGEVIEW_STREAM_ID, pageViewSerde);
  KafkaOutputDescriptor<EnrichedPageView> joinResultOutputDescriptor =
      kafkaSystemDescriptor.getOutputDescriptor(OUTPUT_TOPIC, joinResultSerde);

  RocksDbTableDescriptor<String, Profile> profileTableDescriptor =
      new RocksDbTableDescriptor<String, Profile>("profile-table", KVSerde.of(new StringSerde(), profileSerde));

  appDescriptor.withDefaultSystem(kafkaSystemDescriptor);

  MessageStream<Profile> profileStream = appDescriptor.getInputStream(profileInputDescriptor);
  MessageStream<PageView> pageViewStream = appDescriptor.getInputStream(pageViewInputDescriptor);
  OutputStream<EnrichedPageView> joinResultStream = appDescriptor.getOutputStream(joinResultOutputDescriptor);
  Table<KV<String, Profile>> profileTable = appDescriptor.getTable(profileTableDescriptor);

  profileStream
      .map(profile -> KV.of(profile.userId, profile))
      .sendTo(profileTable);

  pageViewStream
      .partitionBy(pv -> pv.userId, pv -> pv, KVSerde.of(new StringSerde(), pageViewSerde), "join")
      .join(profileTable, new JoinFn())
      .sendTo(joinResultStream);
}
 

@Override
public void describe(StreamApplicationDescriptor app) {

  KafkaSystemDescriptor kafkaSystemDescriptor = new KafkaSystemDescriptor(KAFKA_SYSTEM_NAME)
      .withConsumerZkConnect(KAFKA_CONSUMER_ZK_CONNECT)
      .withProducerBootstrapServers(KAFKA_PRODUCER_BOOTSTRAP_SERVERS)
      .withDefaultStreamConfigs(KAFKA_DEFAULT_STREAM_CONFIGS);

  KafkaInputDescriptor<String> wordInputDescriptor =
      kafkaSystemDescriptor.getInputDescriptor(INPUT_STREAM_ID, new StringSerde());

  KafkaOutputDescriptor<String> countOutputDescriptor =
      kafkaSystemDescriptor.getOutputDescriptor(OUTPUT_STREAM_ID, new StringSerde());

  MyCouchbaseTableWriteFunction writeFn = new MyCouchbaseTableWriteFunction(BUCKET_NAME, CLUSTER_NODES)
      .withBootstrapCarrierDirectPort(COUCHBASE_PORT)
      .withUsernameAndPassword(BUCKET_NAME, BUCKET_PASSWORD)
      .withTimeout(Duration.ofSeconds(5));

  TableRetryPolicy retryPolicy = new TableRetryPolicy()
      .withFixedBackoff(Duration.ofSeconds(1))
      .withStopAfterAttempts(3);

  RemoteTableDescriptor couchbaseTableDescriptor = new RemoteTableDescriptor("couchbase-table")
      .withReadFunction(new NoOpTableReadFunction())
      .withReadRateLimiterDisabled()
      .withWriteFunction(writeFn)
      .withWriteRetryPolicy(retryPolicy)
      .withWriteRateLimit(4);

  app.withDefaultSystem(kafkaSystemDescriptor);
  MessageStream<String> wordStream = app.getInputStream(wordInputDescriptor);
  OutputStream<String> countStream = app.getOutputStream(countOutputDescriptor);
  app.getTable(couchbaseTableDescriptor);

  wordStream
      .flatMap(m -> Arrays.asList(m.split(" ")))
      .filter(word -> word != null && word.length() > 0)
      .map(new MyCountFunction())
      .map(countString -> currentTime() + " " + countString)
      .sendTo(countStream);
}
 

@Override
public void describe(StreamApplicationDescriptor appDescriptor) {

  Duration windowDuration =
      appDescriptor.getConfig().containsKey("deploy.test") ? Duration.ofMillis(10) : Duration.ofSeconds(10);
  // Define a SystemDescriptor for Wikipedia data
  WikipediaSystemDescriptor wikipediaSystemDescriptor = new WikipediaSystemDescriptor("irc.wikimedia.org", 6667);

  // Define InputDescriptors for consuming wikipedia data
  WikipediaInputDescriptor wikipediaInputDescriptor = wikipediaSystemDescriptor
      .getInputDescriptor("en-wikipedia")
      .withChannel(WIKIPEDIA_CHANNEL);
  WikipediaInputDescriptor wiktionaryInputDescriptor = wikipediaSystemDescriptor
      .getInputDescriptor("en-wiktionary")
      .withChannel(WIKTIONARY_CHANNEL);
  WikipediaInputDescriptor wikiNewsInputDescriptor = wikipediaSystemDescriptor
      .getInputDescriptor("en-wikinews")
      .withChannel(WIKINEWS_CHANNEL);

  // Define a system descriptor for Kafka
  KafkaSystemDescriptor kafkaSystemDescriptor = new KafkaSystemDescriptor("kafka")
      .withConsumerZkConnect(KAFKA_CONSUMER_ZK_CONNECT)
      .withProducerBootstrapServers(KAFKA_PRODUCER_BOOTSTRAP_SERVERS)
      .withDefaultStreamConfigs(KAFKA_DEFAULT_STREAM_CONFIGS);

  // Define an output descriptor
  KafkaOutputDescriptor<WikipediaStatsOutput> statsOutputDescriptor =
      kafkaSystemDescriptor.getOutputDescriptor("wikipedia-stats", new JsonSerdeV2<>(WikipediaStatsOutput.class));


  // Set the default system descriptor to Kafka, so that it is used for all
  // internal resources, e.g., kafka topic for checkpointing, coordinator stream.
  appDescriptor.withDefaultSystem(kafkaSystemDescriptor);
  MessageStream<WikipediaFeedEvent> wikipediaEvents = appDescriptor.getInputStream(wikipediaInputDescriptor);
  MessageStream<WikipediaFeedEvent> wiktionaryEvents = appDescriptor.getInputStream(wiktionaryInputDescriptor);
  MessageStream<WikipediaFeedEvent> wikiNewsEvents = appDescriptor.getInputStream(wikiNewsInputDescriptor);
  OutputStream<WikipediaStatsOutput> wikipediaStats = appDescriptor.getOutputStream(statsOutputDescriptor);

  // Merge inputs
  MessageStream<WikipediaFeedEvent> allWikipediaEvents =
      MessageStream.mergeAll(ImmutableList.of(wikipediaEvents, wiktionaryEvents, wikiNewsEvents));


  // Parse, update stats, prepare output, and send
  allWikipediaEvents
      .map(WikipediaParser::parseEvent)
      .window(Windows.tumblingWindow(windowDuration,
          WikipediaStats::new, new WikipediaStatsAggregator(), WikipediaStats.serde()), "statsWindow")
      .map(this::formatOutput)
      .sendTo(wikipediaStats);
}