org.apache.flink.streaming.connectors.kinesis.serialization.KinesisDeserializationSchema Java Examples

/**
 * Creates a Kinesis Data Fetcher.
 *
 * @param streams the streams to subscribe to
 * @param sourceContext context of the source function
 * @param runtimeContext this subtask's runtime context
 * @param configProps the consumer configuration properties
 * @param deserializationSchema deserialization schema
 */
public KinesisDataFetcher(List<String> streams,
						SourceFunction.SourceContext<T> sourceContext,
						RuntimeContext runtimeContext,
						Properties configProps,
						KinesisDeserializationSchema<T> deserializationSchema,
						KinesisShardAssigner shardAssigner,
						AssignerWithPeriodicWatermarks<T> periodicWatermarkAssigner,
						WatermarkTracker watermarkTracker) {
	this(streams,
		sourceContext,
		sourceContext.getCheckpointLock(),
		runtimeContext,
		configProps,
		deserializationSchema,
		shardAssigner,
		periodicWatermarkAssigner,
		watermarkTracker,
		new AtomicReference<>(),
		new ArrayList<>(),
		createInitialSubscribedStreamsToLastDiscoveredShardsState(streams),
		KinesisProxy::create);
}
 

/**
 * Creates a Kinesis Data Fetcher.
 *
 * @param streams the streams to subscribe to
 * @param sourceContext context of the source function
 * @param runtimeContext this subtask's runtime context
 * @param configProps the consumer configuration properties
 * @param deserializationSchema deserialization schema
 */
public KinesisDataFetcher(List<String> streams,
						SourceFunction.SourceContext<T> sourceContext,
						RuntimeContext runtimeContext,
						Properties configProps,
						KinesisDeserializationSchema<T> deserializationSchema,
						KinesisShardAssigner shardAssigner,
						AssignerWithPeriodicWatermarks<T> periodicWatermarkAssigner,
						WatermarkTracker watermarkTracker) {
	this(streams,
		sourceContext,
		sourceContext.getCheckpointLock(),
		runtimeContext,
		configProps,
		deserializationSchema,
		shardAssigner,
		periodicWatermarkAssigner,
		watermarkTracker,
		new AtomicReference<>(),
		new ArrayList<>(),
		createInitialSubscribedStreamsToLastDiscoveredShardsState(streams),
		KinesisProxy::create);
}
 

/**
 * Constructor.
 *
 * @param streams list of streams to fetch data
 * @param sourceContext source context
 * @param runtimeContext runtime context
 * @param configProps config properties
 * @param deserializationSchema deserialization schema
 * @param shardAssigner shard assigner
 */
public DynamoDBStreamsDataFetcher(List<String> streams,
	SourceFunction.SourceContext<T> sourceContext,
	RuntimeContext runtimeContext,
	Properties configProps,
	KinesisDeserializationSchema<T> deserializationSchema,
	KinesisShardAssigner shardAssigner) {

	super(streams,
		sourceContext,
		sourceContext.getCheckpointLock(),
		runtimeContext,
		configProps,
		deserializationSchema,
		shardAssigner,
		null,
		null,
		new AtomicReference<>(),
		new ArrayList<>(),
		createInitialSubscribedStreamsToLastDiscoveredShardsState(streams),
		// use DynamoDBStreamsProxy
		DynamoDBStreamsProxy::create);
}
 

/**
 * Constructor.
 *
 * @param streams list of streams to fetch data
 * @param sourceContext source context
 * @param runtimeContext runtime context
 * @param configProps config properties
 * @param deserializationSchema deserialization schema
 * @param shardAssigner shard assigner
 */
public DynamoDBStreamsDataFetcher(List<String> streams,
	SourceFunction.SourceContext<T> sourceContext,
	RuntimeContext runtimeContext,
	Properties configProps,
	KinesisDeserializationSchema<T> deserializationSchema,
	KinesisShardAssigner shardAssigner) {

	super(streams,
		sourceContext,
		sourceContext.getCheckpointLock(),
		runtimeContext,
		configProps,
		deserializationSchema,
		shardAssigner,
		null,
		null,
		new AtomicReference<>(),
		new ArrayList<>(),
		createInitialSubscribedStreamsToLastDiscoveredShardsState(streams),
		// use DynamoDBStreamsProxy
		DynamoDBStreamsProxy::create);
}
 

/**
 * Create a new DynamoDB streams shard consumer.
 *
 * @param subscribedShardStateIndex the state index of the shard this consumer is subscribed to
 * @param handle stream handle
 * @param lastSeqNum last sequence number
 * @param shardMetricsReporter the reporter to report metrics to
 * @return
 */
@Override
protected ShardConsumer<T> createShardConsumer(
	Integer subscribedShardStateIndex,
	StreamShardHandle handle,
	SequenceNumber lastSeqNum,
	ShardMetricsReporter shardMetricsReporter,
	KinesisDeserializationSchema<T> shardDeserializer) {

	return new ShardConsumer(
		this,
		subscribedShardStateIndex,
		handle,
		lastSeqNum,
		DynamoDBStreamsProxy.create(getConsumerConfiguration()),
		shardMetricsReporter,
		shardDeserializer);
}
 

/**
 * Creates a Kinesis Data Fetcher.
 *
 * @param streams the streams to subscribe to
 * @param sourceContext context of the source function
 * @param runtimeContext this subtask's runtime context
 * @param configProps the consumer configuration properties
 * @param deserializationSchema deserialization schema
 */
public KinesisDataFetcher(List<String> streams,
						SourceFunction.SourceContext<T> sourceContext,
						RuntimeContext runtimeContext,
						Properties configProps,
						KinesisDeserializationSchema<T> deserializationSchema,
						KinesisShardAssigner shardAssigner,
						AssignerWithPeriodicWatermarks<T> periodicWatermarkAssigner,
						WatermarkTracker watermarkTracker) {
	this(streams,
		sourceContext,
		sourceContext.getCheckpointLock(),
		runtimeContext,
		configProps,
		deserializationSchema,
		shardAssigner,
		periodicWatermarkAssigner,
		watermarkTracker,
		new AtomicReference<>(),
		new ArrayList<>(),
		createInitialSubscribedStreamsToLastDiscoveredShardsState(streams),
		KinesisProxy::create);
}
 

/**
 * Create a new shard consumer.
 * Override this method to customize shard consumer behavior in subclasses.
 * @param subscribedShardStateIndex the state index of the shard this consumer is subscribed to
 * @param subscribedShard the shard this consumer is subscribed to
 * @param lastSequenceNum the sequence number in the shard to start consuming
 * @param shardMetricsReporter the reporter to report metrics to
 * @return shard consumer
 */
protected ShardConsumer<T> createShardConsumer(
	Integer subscribedShardStateIndex,
	StreamShardHandle subscribedShard,
	SequenceNumber lastSequenceNum,
	ShardMetricsReporter shardMetricsReporter,
	KinesisDeserializationSchema<T> shardDeserializer) {
	return new ShardConsumer<>(
		this,
		subscribedShardStateIndex,
		subscribedShard,
		lastSequenceNum,
		this.kinesisProxyFactory.create(configProps),
		shardMetricsReporter,
		shardDeserializer);
}
 

/**
 * Constructor.
 *
 * @param streams list of streams to fetch data
 * @param sourceContext source context
 * @param runtimeContext runtime context
 * @param configProps config properties
 * @param deserializationSchema deserialization schema
 * @param shardAssigner shard assigner
 */
public DynamoDBStreamsDataFetcher(List<String> streams,
	SourceFunction.SourceContext<T> sourceContext,
	RuntimeContext runtimeContext,
	Properties configProps,
	KinesisDeserializationSchema<T> deserializationSchema,
	KinesisShardAssigner shardAssigner) {

	super(streams,
		sourceContext,
		sourceContext.getCheckpointLock(),
		runtimeContext,
		configProps,
		deserializationSchema,
		shardAssigner,
		null,
		null,
		new AtomicReference<>(),
		new ArrayList<>(),
		createInitialSubscribedStreamsToLastDiscoveredShardsState(streams),
		// use DynamoDBStreamsProxy
		DynamoDBStreamsProxy::create);
}
 

public TestableKinesisDataFetcher(
		List<String> fakeStreams,
		SourceFunction.SourceContext<T> sourceContext,
		Properties fakeConfiguration,
		KinesisDeserializationSchema<T> deserializationSchema,
		int fakeTotalCountOfSubtasks,
		int fakeIndexOfThisSubtask,
		AtomicReference<Throwable> thrownErrorUnderTest,
		LinkedList<KinesisStreamShardState> subscribedShardsStateUnderTest,
		HashMap<String, String> subscribedStreamsToLastDiscoveredShardIdsStateUnderTest,
		KinesisProxyInterface fakeKinesis) {
	super(
		fakeStreams,
		sourceContext,
		sourceContext.getCheckpointLock(),
		getMockedRuntimeContext(fakeTotalCountOfSubtasks, fakeIndexOfThisSubtask),
		fakeConfiguration,
		deserializationSchema,
		DEFAULT_SHARD_ASSIGNER,
		null,
		null,
		thrownErrorUnderTest,
		subscribedShardsStateUnderTest,
		subscribedStreamsToLastDiscoveredShardIdsStateUnderTest,
		(properties) -> fakeKinesis);

	this.runWaiter = new OneShotLatch();
	this.initialDiscoveryWaiter = new OneShotLatch();
	this.shutdownWaiter = new OneShotLatch();

	this.running = true;
}
 

@SuppressWarnings("unchecked")
DummyFlinkKinesisConsumer(
		Properties properties,
		KinesisDataFetcher<T> fetcher,
		int numParallelSubtasks,
		int subtaskIndex) {
	super("test", mock(KinesisDeserializationSchema.class), properties);
	this.fetcher = fetcher;
	this.numParallelSubtasks = numParallelSubtasks;
	this.subtaskIndex = subtaskIndex;
}
 

@Override
protected KinesisDataFetcher<T> createFetcher(
		List<String> streams,
		SourceFunction.SourceContext<T> sourceContext,
		RuntimeContext runtimeContext,
		Properties configProps,
		KinesisDeserializationSchema<T> deserializationSchema) {
	return fetcher;
}
 

@Override
protected KinesisDataFetcher<T> createFetcher(
		List<String> streams,
		SourceContext<T> sourceContext,
		RuntimeContext runtimeContext,
		Properties configProps,
		KinesisDeserializationSchema<T> deserializer) {
	return mockFetcher;
}
 

public TestFetcher(
		List<String> streams,
		SourceFunction.SourceContext<T> sourceContext,
		RuntimeContext runtimeContext,
		Properties configProps,
		KinesisDeserializationSchema<T> deserializationSchema,
		HashMap<StreamShardMetadata, SequenceNumber> testStateSnapshot,
		List<StreamShardHandle> testInitialDiscoveryShards) {

	super(streams, sourceContext, runtimeContext, configProps, deserializationSchema, DEFAULT_SHARD_ASSIGNER, null, null);

	this.testStateSnapshot = testStateSnapshot;
	this.testInitialDiscoveryShards = testInitialDiscoveryShards;
}
 

public TestableKinesisDataFetcher(
		List<String> fakeStreams,
		SourceFunction.SourceContext<T> sourceContext,
		Properties fakeConfiguration,
		KinesisDeserializationSchema<T> deserializationSchema,
		int fakeTotalCountOfSubtasks,
		int fakeIndexOfThisSubtask,
		AtomicReference<Throwable> thrownErrorUnderTest,
		LinkedList<KinesisStreamShardState> subscribedShardsStateUnderTest,
		HashMap<String, String> subscribedStreamsToLastDiscoveredShardIdsStateUnderTest,
		KinesisProxyInterface fakeKinesis) {
	super(
		fakeStreams,
		sourceContext,
		sourceContext.getCheckpointLock(),
		getMockedRuntimeContext(fakeTotalCountOfSubtasks, fakeIndexOfThisSubtask),
		fakeConfiguration,
		deserializationSchema,
		DEFAULT_SHARD_ASSIGNER,
		null,
		null,
		thrownErrorUnderTest,
		subscribedShardsStateUnderTest,
		subscribedStreamsToLastDiscoveredShardIdsStateUnderTest,
		(properties) -> fakeKinesis);

	this.runWaiter = new OneShotLatch();
	this.initialDiscoveryWaiter = new OneShotLatch();
	this.shutdownWaiter = new OneShotLatch();

	this.running = true;
}
 

public TestableKinesisDataFetcherForShardConsumerException(final List<String> fakeStreams,
		final SourceFunction.SourceContext<T> sourceContext,
		final Properties fakeConfiguration,
		final KinesisDeserializationSchema<T> deserializationSchema,
		final int fakeTotalCountOfSubtasks,
		final int fakeIndexOfThisSubtask,
		final AtomicReference<Throwable> thrownErrorUnderTest,
		final LinkedList<KinesisStreamShardState> subscribedShardsStateUnderTest,
		final HashMap<String, String> subscribedStreamsToLastDiscoveredShardIdsStateUnderTest,
		final KinesisProxyInterface fakeKinesis) {
	super(fakeStreams, sourceContext, fakeConfiguration, deserializationSchema, fakeTotalCountOfSubtasks,
		fakeIndexOfThisSubtask, thrownErrorUnderTest, subscribedShardsStateUnderTest,
		subscribedStreamsToLastDiscoveredShardIdsStateUnderTest, fakeKinesis);
}
 

public TestableKinesisDataFetcherForShardConsumerException(final List<String> fakeStreams,
		final SourceFunction.SourceContext<T> sourceContext,
		final Properties fakeConfiguration,
		final KinesisDeserializationSchema<T> deserializationSchema,
		final int fakeTotalCountOfSubtasks,
		final int fakeIndexOfThisSubtask,
		final AtomicReference<Throwable> thrownErrorUnderTest,
		final LinkedList<KinesisStreamShardState> subscribedShardsStateUnderTest,
		final HashMap<String, String> subscribedStreamsToLastDiscoveredShardIdsStateUnderTest,
		final KinesisProxyInterface fakeKinesis) {
	super(fakeStreams, sourceContext, fakeConfiguration, deserializationSchema, fakeTotalCountOfSubtasks,
		fakeIndexOfThisSubtask, thrownErrorUnderTest, subscribedShardsStateUnderTest,
		subscribedStreamsToLastDiscoveredShardIdsStateUnderTest, fakeKinesis);
}
 

@SuppressWarnings("unchecked")
DummyFlinkKinesisConsumer(
		Properties properties,
		KinesisDataFetcher<T> fetcher,
		int numParallelSubtasks,
		int subtaskIndex) {
	super("test", mock(KinesisDeserializationSchema.class), properties);
	this.fetcher = fetcher;
	this.numParallelSubtasks = numParallelSubtasks;
	this.subtaskIndex = subtaskIndex;
}
 

public TestFetcher(
		List<String> streams,
		SourceFunction.SourceContext<T> sourceContext,
		RuntimeContext runtimeContext,
		Properties configProps,
		KinesisDeserializationSchema<T> deserializationSchema,
		HashMap<StreamShardMetadata, SequenceNumber> testStateSnapshot,
		List<StreamShardHandle> testInitialDiscoveryShards) {

	super(streams, sourceContext, runtimeContext, configProps, deserializationSchema, DEFAULT_SHARD_ASSIGNER, null, null);

	this.testStateSnapshot = testStateSnapshot;
	this.testInitialDiscoveryShards = testInitialDiscoveryShards;
}
 

@Override
protected KinesisDataFetcher<T> createFetcher(
		List<String> streams,
		SourceContext<T> sourceContext,
		RuntimeContext runtimeContext,
		Properties configProps,
		KinesisDeserializationSchema<T> deserializer) {
	return mockFetcher;
}
 

@VisibleForTesting
protected KinesisDataFetcher(List<String> streams,
							SourceFunction.SourceContext<T> sourceContext,
							Object checkpointLock,
							RuntimeContext runtimeContext,
							Properties configProps,
							KinesisDeserializationSchema<T> deserializationSchema,
							KinesisShardAssigner shardAssigner,
							AssignerWithPeriodicWatermarks<T> periodicWatermarkAssigner,
							WatermarkTracker watermarkTracker,
							AtomicReference<Throwable> error,
							List<KinesisStreamShardState> subscribedShardsState,
							HashMap<String, String> subscribedStreamsToLastDiscoveredShardIds,
							FlinkKinesisProxyFactory kinesisProxyFactory) {
	this.streams = checkNotNull(streams);
	this.configProps = checkNotNull(configProps);
	this.sourceContext = checkNotNull(sourceContext);
	this.checkpointLock = checkNotNull(checkpointLock);
	this.runtimeContext = checkNotNull(runtimeContext);
	this.totalNumberOfConsumerSubtasks = runtimeContext.getNumberOfParallelSubtasks();
	this.indexOfThisConsumerSubtask = runtimeContext.getIndexOfThisSubtask();
	this.deserializationSchema = checkNotNull(deserializationSchema);
	this.shardAssigner = checkNotNull(shardAssigner);
	this.periodicWatermarkAssigner = periodicWatermarkAssigner;
	this.watermarkTracker = watermarkTracker;
	this.kinesisProxyFactory = checkNotNull(kinesisProxyFactory);
	this.kinesis = kinesisProxyFactory.create(configProps);

	this.consumerMetricGroup = runtimeContext.getMetricGroup()
		.addGroup(KinesisConsumerMetricConstants.KINESIS_CONSUMER_METRICS_GROUP);

	this.error = checkNotNull(error);
	this.subscribedShardsState = checkNotNull(subscribedShardsState);
	this.subscribedStreamsToLastDiscoveredShardIds = checkNotNull(subscribedStreamsToLastDiscoveredShardIds);

	this.shardConsumersExecutor =
		createShardConsumersThreadPool(runtimeContext.getTaskNameWithSubtasks());
	this.recordEmitter = createRecordEmitter(configProps);
}
 

@Override
protected KinesisDataFetcher<T> createFetcher(
		List<String> streams,
		SourceFunction.SourceContext<T> sourceContext,
		RuntimeContext runtimeContext,
		Properties configProps,
		KinesisDeserializationSchema<T> deserializationSchema) {
	return fetcher;
}
 

private KinesisDeserializationSchema<T> getClonedDeserializationSchema() {
	try {
		return InstantiationUtil.clone(deserializationSchema, runtimeContext.getUserCodeClassLoader());
	} catch (IOException | ClassNotFoundException ex) {
		// this really shouldn't happen; simply wrap it around a runtime exception
		throw new RuntimeException(ex);
	}
}
 

@Override
protected KinesisDataFetcher<T> createFetcher(
		List<String> streams,
		SourceFunction.SourceContext<T> sourceContext,
		RuntimeContext runtimeContext,
		Properties configProps,
		KinesisDeserializationSchema<T> deserializationSchema) {
	return new DynamoDBStreamsDataFetcher<T>(
			streams,
			sourceContext,
			runtimeContext,
			configProps,
			deserializationSchema,
			getShardAssigner());
}
 

/**
 * Creates a new Flink Kinesis Consumer.
 *
 * <p>The AWS credentials to be used, AWS region of the Kinesis streams, initial position to start streaming
 * from are configured with a {@link Properties} instance.</p>
 *
 * @param streams
 *           The AWS Kinesis streams to read from.
 * @param deserializer
 *           The keyed deserializer used to convert raw bytes of Kinesis records to Java objects.
 * @param configProps
 *           The properties used to configure AWS credentials, AWS region, and initial starting position.
 */
public FlinkKinesisConsumer(List<String> streams, KinesisDeserializationSchema<T> deserializer, Properties configProps) {
	checkNotNull(streams, "streams can not be null");
	checkArgument(streams.size() != 0, "must be consuming at least 1 stream");
	checkArgument(!streams.contains(""), "stream names cannot be empty Strings");
	this.streams = streams;

	this.configProps = checkNotNull(configProps, "configProps can not be null");

	// check the configuration properties for any conflicting settings
	KinesisConfigUtil.validateConsumerConfiguration(this.configProps);

	checkNotNull(deserializer, "deserializer can not be null");
	checkArgument(
		InstantiationUtil.isSerializable(deserializer),
		"The provided deserialization schema is not serializable: " + deserializer.getClass().getName() + ". " +
			"Please check that it does not contain references to non-serializable instances.");
	this.deserializer = deserializer;

	if (LOG.isInfoEnabled()) {
		StringBuilder sb = new StringBuilder();
		for (String stream : streams) {
			sb.append(stream).append(", ");
		}
		LOG.info("Flink Kinesis Consumer is going to read the following streams: {}", sb.toString());
	}
}
 

/** This method is exposed for tests that need to mock the KinesisDataFetcher in the consumer. */
protected KinesisDataFetcher<T> createFetcher(
		List<String> streams,
		SourceFunction.SourceContext<T> sourceContext,
		RuntimeContext runtimeContext,
		Properties configProps,
		KinesisDeserializationSchema<T> deserializationSchema) {

	return new KinesisDataFetcher<>(streams, sourceContext, runtimeContext, configProps, deserializationSchema, shardAssigner, periodicWatermarkAssigner, watermarkTracker);
}
 

@Override
protected KinesisDataFetcher<T> createFetcher(
		List<String> streams,
		SourceContext<T> sourceContext,
		RuntimeContext runtimeContext,
		Properties configProps,
		KinesisDeserializationSchema<T> deserializer) {
	return mockFetcher;
}
 

@VisibleForTesting
protected KinesisDataFetcher(List<String> streams,
							SourceFunction.SourceContext<T> sourceContext,
							Object checkpointLock,
							RuntimeContext runtimeContext,
							Properties configProps,
							KinesisDeserializationSchema<T> deserializationSchema,
							KinesisShardAssigner shardAssigner,
							AssignerWithPeriodicWatermarks<T> periodicWatermarkAssigner,
							WatermarkTracker watermarkTracker,
							AtomicReference<Throwable> error,
							List<KinesisStreamShardState> subscribedShardsState,
							HashMap<String, String> subscribedStreamsToLastDiscoveredShardIds,
							FlinkKinesisProxyFactory kinesisProxyFactory) {
	this.streams = checkNotNull(streams);
	this.configProps = checkNotNull(configProps);
	this.sourceContext = checkNotNull(sourceContext);
	this.checkpointLock = checkNotNull(checkpointLock);
	this.runtimeContext = checkNotNull(runtimeContext);
	this.totalNumberOfConsumerSubtasks = runtimeContext.getNumberOfParallelSubtasks();
	this.indexOfThisConsumerSubtask = runtimeContext.getIndexOfThisSubtask();
	this.deserializationSchema = checkNotNull(deserializationSchema);
	this.shardAssigner = checkNotNull(shardAssigner);
	this.periodicWatermarkAssigner = periodicWatermarkAssigner;
	this.watermarkTracker = watermarkTracker;
	this.kinesisProxyFactory = checkNotNull(kinesisProxyFactory);
	this.kinesis = kinesisProxyFactory.create(configProps);

	this.consumerMetricGroup = runtimeContext.getMetricGroup()
		.addGroup(KinesisConsumerMetricConstants.KINESIS_CONSUMER_METRICS_GROUP);

	this.error = checkNotNull(error);
	this.subscribedShardsState = checkNotNull(subscribedShardsState);
	this.subscribedStreamsToLastDiscoveredShardIds = checkNotNull(subscribedStreamsToLastDiscoveredShardIds);

	this.shardConsumersExecutor =
		createShardConsumersThreadPool(runtimeContext.getTaskNameWithSubtasks());
	this.recordEmitter = createRecordEmitter(configProps);
}
 

protected KinesisDeserializationSchema<T> getClonedDeserializationSchema() {
	try {
		return InstantiationUtil.clone(deserializationSchema, runtimeContext.getUserCodeClassLoader());
	} catch (IOException | ClassNotFoundException ex) {
		// this really shouldn't happen; simply wrap it around a runtime exception
		throw new RuntimeException(ex);
	}
}
 

@Override
protected KinesisDataFetcher<T> createFetcher(
		List<String> streams,
		SourceFunction.SourceContext<T> sourceContext,
		RuntimeContext runtimeContext,
		Properties configProps,
		KinesisDeserializationSchema<T> deserializationSchema) {
	return new DynamoDBStreamsDataFetcher<T>(
			streams,
			sourceContext,
			runtimeContext,
			configProps,
			deserializationSchema,
			getShardAssigner());
}
 

/**
 * Creates a new Flink Kinesis Consumer.
 *
 * <p>The AWS credentials to be used, AWS region of the Kinesis streams, initial position to start streaming
 * from are configured with a {@link Properties} instance.</p>
 *
 * @param streams
 *           The AWS Kinesis streams to read from.
 * @param deserializer
 *           The keyed deserializer used to convert raw bytes of Kinesis records to Java objects.
 * @param configProps
 *           The properties used to configure AWS credentials, AWS region, and initial starting position.
 */
public FlinkKinesisConsumer(List<String> streams, KinesisDeserializationSchema<T> deserializer, Properties configProps) {
	checkNotNull(streams, "streams can not be null");
	checkArgument(streams.size() != 0, "must be consuming at least 1 stream");
	checkArgument(!streams.contains(""), "stream names cannot be empty Strings");
	this.streams = streams;

	this.configProps = checkNotNull(configProps, "configProps can not be null");

	// check the configuration properties for any conflicting settings
	KinesisConfigUtil.validateConsumerConfiguration(this.configProps);

	checkNotNull(deserializer, "deserializer can not be null");
	checkArgument(
		InstantiationUtil.isSerializable(deserializer),
		"The provided deserialization schema is not serializable: " + deserializer.getClass().getName() + ". " +
			"Please check that it does not contain references to non-serializable instances.");
	this.deserializer = deserializer;

	if (LOG.isInfoEnabled()) {
		StringBuilder sb = new StringBuilder();
		for (String stream : streams) {
			sb.append(stream).append(", ");
		}
		LOG.info("Flink Kinesis Consumer is going to read the following streams: {}", sb.toString());
	}
}