org.apache.kafka.streams.kstream.SessionWindows Java Examples

@Override public Topology get() {
  StreamsBuilder builder = new StreamsBuilder();
  if (aggregationEnabled) {
    // Aggregate Spans to Traces
    KStream<String, List<Span>> tracesStream =
        builder.stream(spansTopic, Consumed.with(Serdes.String(), spansSerde))
            .groupByKey()
            // how long to wait for another span
            .windowedBy(SessionWindows.with(traceTimeout).grace(Duration.ZERO))
            .aggregate(ArrayList::new, aggregateSpans(), joinAggregates(),
                Materialized
                    .<String, List<Span>>as(
                        Stores.persistentSessionStore(TRACE_AGGREGATION_STORE,
                            Duration.ofDays(1)))
                    .withKeySerde(Serdes.String())
                    .withValueSerde(spansSerde)
                    .withLoggingDisabled()
                    .withCachingEnabled())
            // hold until a new record tells that a window is closed and we can process it further
            .suppress(untilWindowCloses(unbounded()))
            .toStream()
            .selectKey((windowed, spans) -> windowed.key());
    // Downstream to traces topic
    tracesStream.to(traceTopic, Produced.with(Serdes.String(), spansSerde));
    // Map to dependency links
    tracesStream.flatMapValues(spansToDependencyLinks())
        .selectKey((key, value) -> linkKey(value))
        .to(dependencyTopic, Produced.with(Serdes.String(), dependencyLinkSerde));
  }
  return builder.build();
}
 

@SuppressWarnings("unchecked")
@Override
public KTable applyAggregate(final KGroupedStream groupedStream,
                             final Initializer initializer,
                             final UdafAggregator aggregator,
                             final Materialized<String, GenericRow, ?> materialized) {
  return groupedStream.windowedBy(SessionWindows.with(sizeUnit.toMillis(gap)))
      .aggregate(initializer, aggregator, aggregator.getMerger(),
          materialized);
}
 

public static void main(String[] args) {

        if(args.length < 2){
            LOG.error("Need to specify host, port");
            System.exit(1);
        }

        String host = args[0];
        int port = Integer.parseInt(args[1]);
        final HostInfo hostInfo = new HostInfo(host, port);

        Properties properties = getProperties();
        properties.put(StreamsConfig.APPLICATION_SERVER_CONFIG, host+":"+port);

        StreamsConfig streamsConfig = new StreamsConfig(properties);
        Serde<String> stringSerde = Serdes.String();
        Serde<Long> longSerde = Serdes.Long();
        Serde<StockTransaction> stockTransactionSerde = StreamsSerdes.StockTransactionSerde();
        WindowedSerializer<String> windowedSerializer = new WindowedSerializer<>(stringSerde.serializer());
        WindowedDeserializer<String> windowedDeserializer = new WindowedDeserializer<>(stringSerde.deserializer());
        Serde<Windowed<String>> windowedSerde = Serdes.serdeFrom(windowedSerializer, windowedDeserializer);
        Serde<CustomerTransactions> customerTransactionsSerde = StreamsSerdes.CustomerTransactionsSerde();

        Aggregator<String, StockTransaction, Integer> sharesAggregator = (k, v, i) -> v.getShares() + i;

        StreamsBuilder builder = new StreamsBuilder();

        // data is already coming in keyed
        KStream<String, StockTransaction> stockTransactionKStream = builder.stream(MockDataProducer.STOCK_TRANSACTIONS_TOPIC, Consumed.with(stringSerde, stockTransactionSerde)
                .withOffsetResetPolicy(Topology.AutoOffsetReset.LATEST));


        stockTransactionKStream.map((k,v) -> KeyValue.pair(v.getSector(), v))
                .groupByKey(Serialized.with(stringSerde, stockTransactionSerde))
                .count(Materialized.as("TransactionsBySector"))
                .toStream()
                .peek((k,v) -> LOG.info("Transaction count for {} {}", k, v))
                .to("sector-transaction-counts", Produced.with(stringSerde, longSerde));
        
        stockTransactionKStream.map((k,v) -> KeyValue.pair(v.getCustomerId(), v))
                .groupByKey(Serialized.with(stringSerde, stockTransactionSerde))
                .windowedBy(SessionWindows.with(TimeUnit.MINUTES.toMillis(60)).until(TimeUnit.MINUTES.toMillis(120)))
                .aggregate(CustomerTransactions::new,(k, v, ct) -> ct.update(v),
                        (k, ct, other)-> ct.merge(other),
                        Materialized.<String, CustomerTransactions, SessionStore<Bytes, byte[]>>as("CustomerPurchaseSessions")
                                .withKeySerde(stringSerde).withValueSerde(customerTransactionsSerde))
                .toStream()
                .peek((k,v) -> LOG.info("Session info for {} {}", k, v))
                .to("session-transactions", Produced.with(windowedSerde, customerTransactionsSerde));


        stockTransactionKStream.groupByKey(Serialized.with(stringSerde, stockTransactionSerde))
                .windowedBy(TimeWindows.of(10000))
                .aggregate(() -> 0, sharesAggregator,
                        Materialized.<String, Integer, WindowStore<Bytes, byte[]>>as("NumberSharesPerPeriod")
                                .withKeySerde(stringSerde)
                                .withValueSerde(Serdes.Integer()))
                .toStream().peek((k,v)->LOG.info("key is {} value is {}", k, v))
                .to("transaction-count", Produced.with(windowedSerde,Serdes.Integer()));


        KafkaStreams kafkaStreams = new KafkaStreams(builder.build(), streamsConfig);
        InteractiveQueryServer queryServer = new InteractiveQueryServer(kafkaStreams, hostInfo);
        StateRestoreHttpReporter restoreReporter = new StateRestoreHttpReporter(queryServer);

        queryServer.init();

        kafkaStreams.setGlobalStateRestoreListener(restoreReporter);

        kafkaStreams.setStateListener(((newState, oldState) -> {
            if (newState == KafkaStreams.State.RUNNING && oldState == KafkaStreams.State.REBALANCING) {
                LOG.info("Setting the query server to ready");
                queryServer.setReady(true);
            } else if (newState != KafkaStreams.State.RUNNING) {
                LOG.info("State not RUNNING, disabling the query server");
                queryServer.setReady(false);
            }
        }));

        kafkaStreams.setUncaughtExceptionHandler((t, e) -> {
            LOG.error("Thread {} had a fatal error {}", t, e, e);
            shutdown(kafkaStreams, queryServer);
        });


        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
            shutdown(kafkaStreams, queryServer);
        }));

        LOG.info("Stock Analysis KStream Interactive Query App Started");
        kafkaStreams.cleanUp();
        kafkaStreams.start();
    }
 

public static void main(String[] args) throws Exception {


        StreamsConfig streamsConfig = new StreamsConfig(getProperties());

        Serde<String> stringSerde = Serdes.String();
        Serde<StockTransaction> transactionSerde = StreamsSerdes.StockTransactionSerde();
        Serde<TransactionSummary> transactionKeySerde = StreamsSerdes.TransactionSummarySerde();

        StreamsBuilder builder = new StreamsBuilder();
        long twentySeconds = 1000 * 20;
        long fifteenMinutes = 1000 * 60 * 15;
        long fiveSeconds = 1000 * 5;
        KTable<Windowed<TransactionSummary>, Long> customerTransactionCounts =
                 builder.stream(STOCK_TRANSACTIONS_TOPIC, Consumed.with(stringSerde, transactionSerde).withOffsetResetPolicy(LATEST))
                .groupBy((noKey, transaction) -> TransactionSummary.from(transaction),
                        Serialized.with(transactionKeySerde, transactionSerde))
                 // session window comment line below and uncomment another line below for a different window example
                .windowedBy(SessionWindows.with(twentySeconds).until(fifteenMinutes)).count();

                //The following are examples of different windows examples

                //Tumbling window with timeout 15 minutes
                //.windowedBy(TimeWindows.of(twentySeconds).until(fifteenMinutes)).count();

                //Tumbling window with default timeout 24 hours
                //.windowedBy(TimeWindows.of(twentySeconds)).count();

                //Hopping window 
                //.windowedBy(TimeWindows.of(twentySeconds).advanceBy(fiveSeconds).until(fifteenMinutes)).count();

        customerTransactionCounts.toStream().print(Printed.<Windowed<TransactionSummary>, Long>toSysOut().withLabel("Customer Transactions Counts"));

        KStream<String, TransactionSummary> countStream = customerTransactionCounts.toStream().map((window, count) -> {
                      TransactionSummary transactionSummary = window.key();
                      String newKey = transactionSummary.getIndustry();
                      transactionSummary.setSummaryCount(count);
                      return KeyValue.pair(newKey, transactionSummary);
        });

        KTable<String, String> financialNews = builder.table( "financial-news", Consumed.with(EARLIEST));


        ValueJoiner<TransactionSummary, String, String> valueJoiner = (txnct, news) ->
                String.format("%d shares purchased %s related news [%s]", txnct.getSummaryCount(), txnct.getStockTicker(), news);

        KStream<String,String> joined = countStream.leftJoin(financialNews, valueJoiner, Joined.with(stringSerde, transactionKeySerde, stringSerde));

        joined.print(Printed.<String, String>toSysOut().withLabel("Transactions and News"));



        KafkaStreams kafkaStreams = new KafkaStreams(builder.build(), streamsConfig);
        kafkaStreams.cleanUp();
        
        kafkaStreams.setUncaughtExceptionHandler((t, e) -> {
            LOG.error("had exception ", e);
        });
        CustomDateGenerator dateGenerator = CustomDateGenerator.withTimestampsIncreasingBy(Duration.ofMillis(750));
        
        DataGenerator.setTimestampGenerator(dateGenerator::get);
        
        MockDataProducer.produceStockTransactions(2, 5, 3, false);

        LOG.info("Starting CountingWindowing and KTableJoins Example");
        kafkaStreams.cleanUp();
        kafkaStreams.start();
        Thread.sleep(65000);
        LOG.info("Shutting down the CountingWindowing and KTableJoins Example Application now");
        kafkaStreams.close();
        MockDataProducer.shutdown();
    }
 

public static void main(String[] args) throws Exception {


        StreamsConfig streamsConfig = new StreamsConfig(getProperties());

        Serde<String> stringSerde = Serdes.String();
        Serde<StockTransaction> transactionSerde = StreamsSerdes.StockTransactionSerde();
        Serde<TransactionSummary> transactionSummarySerde = StreamsSerdes.TransactionSummarySerde();


        StreamsBuilder builder = new StreamsBuilder();
        long twentySeconds = 1000 * 20;

        KeyValueMapper<Windowed<TransactionSummary>, Long, KeyValue<String, TransactionSummary>> transactionMapper = (window, count) -> {
            TransactionSummary transactionSummary = window.key();
            String newKey = transactionSummary.getIndustry();
            transactionSummary.setSummaryCount(count);
            return KeyValue.pair(newKey, transactionSummary);
        };

        KStream<String, TransactionSummary> countStream =
                builder.stream( STOCK_TRANSACTIONS_TOPIC, Consumed.with(stringSerde, transactionSerde).withOffsetResetPolicy(LATEST))
                        .groupBy((noKey, transaction) -> TransactionSummary.from(transaction), Serialized.with(transactionSummarySerde, transactionSerde))
                        .windowedBy(SessionWindows.with(twentySeconds)).count()
                        .toStream().map(transactionMapper);

        GlobalKTable<String, String> publicCompanies = builder.globalTable(COMPANIES.topicName());
        GlobalKTable<String, String> clients = builder.globalTable(CLIENTS.topicName());


        countStream.leftJoin(publicCompanies, (key, txn) -> txn.getStockTicker(),TransactionSummary::withCompanyName)
                .leftJoin(clients, (key, txn) -> txn.getCustomerId(), TransactionSummary::withCustomerName)
                .print(Printed.<String, TransactionSummary>toSysOut().withLabel("Resolved Transaction Summaries"));


        
        KafkaStreams kafkaStreams = new KafkaStreams(builder.build(), streamsConfig);
        kafkaStreams.cleanUp();


        kafkaStreams.setUncaughtExceptionHandler((t, e) -> {
            LOG.error("had exception ", e);
        });

        CustomDateGenerator dateGenerator = CustomDateGenerator.withTimestampsIncreasingBy(Duration.ofMillis(750));

        DataGenerator.setTimestampGenerator(dateGenerator::get);

        MockDataProducer.produceStockTransactions(2, 5, 3, true);

        LOG.info("Starting GlobalKTable Example");
        kafkaStreams.cleanUp();
        kafkaStreams.start();
        Thread.sleep(65000);
        LOG.info("Shutting down the GlobalKTable Example Application now");
        kafkaStreams.close();
        MockDataProducer.shutdown();
    }