org.apache.flink.queryablestate.client.VoidNamespaceSerializer Java Examples

/**
 * Tests map serialization and deserialization match.
 *
 * @see KvStateRequestSerializerTest#testMapSerialization()
 * KvStateRequestSerializerTest#testMapSerialization() using the heap state back-end
 * test
 */
@Test
public void testMapSerialization() throws Exception {
	final long key = 0L;

	// objects for RocksDB state list serialisation
	final RocksDBKeyedStateBackend<Long> longHeapKeyedStateBackend = RocksDBTestUtils
		.builderForTestDefaults(temporaryFolder.getRoot(), LongSerializer.INSTANCE)
		.build();

	longHeapKeyedStateBackend.setCurrentKey(key);

	final InternalMapState<Long, VoidNamespace, Long, String> mapState =
			(InternalMapState<Long, VoidNamespace, Long, String>)
					longHeapKeyedStateBackend.getPartitionedState(
							VoidNamespace.INSTANCE,
							VoidNamespaceSerializer.INSTANCE,
							new MapStateDescriptor<>("test", LongSerializer.INSTANCE, StringSerializer.INSTANCE));

	KvStateRequestSerializerTest.testMapSerialization(key, mapState);
	longHeapKeyedStateBackend.dispose();
}
 

/**
 * Tests list serialization and deserialization match.
 *
 * @see KvStateRequestSerializerTest#testListSerialization()
 * KvStateRequestSerializerTest#testListSerialization() using the heap state back-end
 * test
 */
@Test
public void testListSerialization() throws Exception {
	final long key = 0L;

	final RocksDBKeyedStateBackend<Long> longHeapKeyedStateBackend = RocksDBTestUtils
		.builderForTestDefaults(temporaryFolder.getRoot(), LongSerializer.INSTANCE)
		.build();

	longHeapKeyedStateBackend.setCurrentKey(key);

	final InternalListState<Long, VoidNamespace, Long> listState = longHeapKeyedStateBackend.createInternalState(VoidNamespaceSerializer.INSTANCE,
			new ListStateDescriptor<>("test", LongSerializer.INSTANCE));

	KvStateRequestSerializerTest.testListSerialization(key, listState);
	longHeapKeyedStateBackend.dispose();
}
 

/**
 * Verifies that the serialization of a list using the given list state
 * matches the deserialization with {@link KvStateSerializer#deserializeList}.
 *
 * @param key
 * 		key of the list state
 * @param listState
 * 		list state using the {@link VoidNamespace}, must also be a {@link InternalKvState} instance
 *
 * @throws Exception
 */
public static void testListSerialization(
		final long key,
		final InternalListState<Long, VoidNamespace, Long> listState) throws Exception {

	TypeSerializer<Long> valueSerializer = LongSerializer.INSTANCE;
	listState.setCurrentNamespace(VoidNamespace.INSTANCE);

	// List
	final int numElements = 10;

	final List<Long> expectedValues = new ArrayList<>();
	for (int i = 0; i < numElements; i++) {
		final long value = ThreadLocalRandom.current().nextLong();
		expectedValues.add(value);
		listState.add(value);
	}

	final byte[] serializedKey =
		KvStateSerializer.serializeKeyAndNamespace(
			key, LongSerializer.INSTANCE,
			VoidNamespace.INSTANCE, VoidNamespaceSerializer.INSTANCE);

	final byte[] serializedValues = listState.getSerializedValue(
			serializedKey,
			listState.getKeySerializer(),
			listState.getNamespaceSerializer(),
			listState.getValueSerializer());

	List<Long> actualValues = KvStateSerializer.deserializeList(serializedValues, valueSerializer);
	assertEquals(expectedValues, actualValues);

	// Single value
	long expectedValue = ThreadLocalRandom.current().nextLong();
	byte[] serializedValue = KvStateSerializer.serializeValue(expectedValue, valueSerializer);
	List<Long> actualValue = KvStateSerializer.deserializeList(serializedValue, valueSerializer);
	assertEquals(1, actualValue.size());
	assertEquals(expectedValue, actualValue.get(0).longValue());
}
 

@Override
public void open() throws Exception {
	super.open();
	this.state = getKeyedStateBackend().getPartitionedState(
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE,
			stateDescriptor);
}
 

/**
 * Tests map serialization utils.
 */
@Test
public void testMapSerialization() throws Exception {
	final long key = 0L;
	final HeapKeyedStateBackend<Long> longHeapKeyedStateBackend = getLongHeapKeyedStateBackend(key);

	final InternalMapState<Long, VoidNamespace, Long, String> mapState =
			(InternalMapState<Long, VoidNamespace, Long, String>)
					longHeapKeyedStateBackend.getPartitionedState(
							VoidNamespace.INSTANCE,
							VoidNamespaceSerializer.INSTANCE,
							new MapStateDescriptor<>("test", LongSerializer.INSTANCE, StringSerializer.INSTANCE));

	testMapSerialization(key, mapState);
}
 

/**
 * Verifies that the serialization of a list using the given list state
 * matches the deserialization with {@link KvStateSerializer#deserializeList}.
 *
 * @param key
 * 		key of the list state
 * @param listState
 * 		list state using the {@link VoidNamespace}, must also be a {@link InternalKvState} instance
 *
 * @throws Exception
 */
public static void testListSerialization(
		final long key,
		final InternalListState<Long, VoidNamespace, Long> listState) throws Exception {

	TypeSerializer<Long> valueSerializer = LongSerializer.INSTANCE;
	listState.setCurrentNamespace(VoidNamespace.INSTANCE);

	// List
	final int numElements = 10;

	final List<Long> expectedValues = new ArrayList<>();
	for (int i = 0; i < numElements; i++) {
		final long value = ThreadLocalRandom.current().nextLong();
		expectedValues.add(value);
		listState.add(value);
	}

	final byte[] serializedKey =
		KvStateSerializer.serializeKeyAndNamespace(
			key, LongSerializer.INSTANCE,
			VoidNamespace.INSTANCE, VoidNamespaceSerializer.INSTANCE);

	final byte[] serializedValues = listState.getSerializedValue(
			serializedKey,
			listState.getKeySerializer(),
			listState.getNamespaceSerializer(),
			listState.getValueSerializer());

	List<Long> actualValues = KvStateSerializer.deserializeList(serializedValues, valueSerializer);
	assertEquals(expectedValues, actualValues);

	// Single value
	long expectedValue = ThreadLocalRandom.current().nextLong();
	byte[] serializedValue = KvStateSerializer.serializeValue(expectedValue, valueSerializer);
	List<Long> actualValue = KvStateSerializer.deserializeList(serializedValue, valueSerializer);
	assertEquals(1, actualValue.size());
	assertEquals(expectedValue, actualValue.get(0).longValue());
}
 

/**
 * Tests list serialization utils.
 */
@Test
public void testListSerialization() throws Exception {
	final long key = 0L;
	final HeapKeyedStateBackend<Long> longHeapKeyedStateBackend = getLongHeapKeyedStateBackend(key);

	final InternalListState<Long, VoidNamespace, Long> listState = longHeapKeyedStateBackend.createInternalState(
		VoidNamespaceSerializer.INSTANCE,
		new ListStateDescriptor<>("test", LongSerializer.INSTANCE));

	testListSerialization(key, listState);
}
 

@Override
public void open() throws Exception {
	super.open();
	this.state = getKeyedStateBackend().getPartitionedState(
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE,
			stateDescriptor);
}
 

/**
 * Tests list serialization and deserialization match.
 *
 * @see KvStateRequestSerializerTest#testListSerialization()
 * KvStateRequestSerializerTest#testListSerialization() using the heap state back-end
 * test
 */
@Test
public void testListSerialization() throws Exception {
	final long key = 0L;

	// objects for RocksDB state list serialisation
	DBOptions dbOptions = PredefinedOptions.DEFAULT.createDBOptions();
	dbOptions.setCreateIfMissing(true);
	ExecutionConfig executionConfig = new ExecutionConfig();
	final RocksDBKeyedStateBackend<Long> longHeapKeyedStateBackend =
		new RocksDBKeyedStateBackendBuilder<>(
			"no-op",
			ClassLoader.getSystemClassLoader(),
			temporaryFolder.getRoot(),
			dbOptions,
			stateName -> PredefinedOptions.DEFAULT.createColumnOptions(),
			mock(TaskKvStateRegistry.class),
			LongSerializer.INSTANCE,
			1,
			new KeyGroupRange(0, 0),
			executionConfig,
			TestLocalRecoveryConfig.disabled(),
			RocksDBStateBackend.PriorityQueueStateType.HEAP,
			TtlTimeProvider.DEFAULT,
			new UnregisteredMetricsGroup(),
			Collections.emptyList(),
			AbstractStateBackend.getCompressionDecorator(executionConfig),
			new CloseableRegistry()
		).build();
	longHeapKeyedStateBackend.setCurrentKey(key);

	final InternalListState<Long, VoidNamespace, Long> listState = longHeapKeyedStateBackend.createInternalState(VoidNamespaceSerializer.INSTANCE,
			new ListStateDescriptor<>("test", LongSerializer.INSTANCE));

	KvStateRequestSerializerTest.testListSerialization(key, listState);
	longHeapKeyedStateBackend.dispose();
}
 

/**
 * Tests map serialization utils.
 */
@Test
public void testMapSerialization() throws Exception {
	final long key = 0L;
	final HeapKeyedStateBackend<Long> longHeapKeyedStateBackend = getLongHeapKeyedStateBackend(key);

	final InternalMapState<Long, VoidNamespace, Long, String> mapState =
			(InternalMapState<Long, VoidNamespace, Long, String>)
					longHeapKeyedStateBackend.getPartitionedState(
							VoidNamespace.INSTANCE,
							VoidNamespaceSerializer.INSTANCE,
							new MapStateDescriptor<>("test", LongSerializer.INSTANCE, StringSerializer.INSTANCE));

	testMapSerialization(key, mapState);
}
 

/**
 * Verifies that the serialization of a list using the given list state
 * matches the deserialization with {@link KvStateSerializer#deserializeList}.
 *
 * @param key
 * 		key of the list state
 * @param listState
 * 		list state using the {@link VoidNamespace}, must also be a {@link InternalKvState} instance
 *
 * @throws Exception
 */
public static void testListSerialization(
		final long key,
		final InternalListState<Long, VoidNamespace, Long> listState) throws Exception {

	TypeSerializer<Long> valueSerializer = LongSerializer.INSTANCE;
	listState.setCurrentNamespace(VoidNamespace.INSTANCE);

	// List
	final int numElements = 10;

	final List<Long> expectedValues = new ArrayList<>();
	for (int i = 0; i < numElements; i++) {
		final long value = ThreadLocalRandom.current().nextLong();
		expectedValues.add(value);
		listState.add(value);
	}

	final byte[] serializedKey =
		KvStateSerializer.serializeKeyAndNamespace(
			key, LongSerializer.INSTANCE,
			VoidNamespace.INSTANCE, VoidNamespaceSerializer.INSTANCE);

	final byte[] serializedValues = listState.getSerializedValue(
			serializedKey,
			listState.getKeySerializer(),
			listState.getNamespaceSerializer(),
			listState.getValueSerializer());

	List<Long> actualValues = KvStateSerializer.deserializeList(serializedValues, valueSerializer);
	assertEquals(expectedValues, actualValues);

	// Single value
	long expectedValue = ThreadLocalRandom.current().nextLong();
	byte[] serializedValue = KvStateSerializer.serializeValue(expectedValue, valueSerializer);
	List<Long> actualValue = KvStateSerializer.deserializeList(serializedValue, valueSerializer);
	assertEquals(1, actualValue.size());
	assertEquals(expectedValue, actualValue.get(0).longValue());
}
 

/**
 * Tests list serialization utils.
 */
@Test
public void testListSerialization() throws Exception {
	final long key = 0L;
	final HeapKeyedStateBackend<Long> longHeapKeyedStateBackend = getLongHeapKeyedStateBackend(key);

	final InternalListState<Long, VoidNamespace, Long> listState = longHeapKeyedStateBackend.createInternalState(
		VoidNamespaceSerializer.INSTANCE,
		new ListStateDescriptor<>("test", LongSerializer.INSTANCE));

	testListSerialization(key, listState);
}
 

/**
 * Tests list serialization utils.
 */
@Test
public void testListSerialization() throws Exception {
	final long key = 0L;
	final HeapKeyedStateBackend<Long> longHeapKeyedStateBackend = getLongHeapKeyedStateBackend(key);

	final InternalListState<Long, VoidNamespace, Long> listState = longHeapKeyedStateBackend.createInternalState(
		VoidNamespaceSerializer.INSTANCE,
		new ListStateDescriptor<>("test", LongSerializer.INSTANCE));

	testListSerialization(key, listState);
}
 

/**
 * Tests map serialization utils.
 */
@Test
public void testMapSerialization() throws Exception {
	final long key = 0L;
	final HeapKeyedStateBackend<Long> longHeapKeyedStateBackend = getLongHeapKeyedStateBackend(key);

	final InternalMapState<Long, VoidNamespace, Long, String> mapState =
			(InternalMapState<Long, VoidNamespace, Long, String>)
					longHeapKeyedStateBackend.getPartitionedState(
							VoidNamespace.INSTANCE,
							VoidNamespaceSerializer.INSTANCE,
							new MapStateDescriptor<>("test", LongSerializer.INSTANCE, StringSerializer.INSTANCE));

	testMapSerialization(key, mapState);
}
 

/**
 * Tests list serialization and deserialization match.
 *
 * @see KvStateRequestSerializerTest#testListSerialization()
 * KvStateRequestSerializerTest#testListSerialization() using the heap state back-end
 * test
 */
@Test
public void testListSerialization() throws Exception {
	final long key = 0L;

	// objects for RocksDB state list serialisation
	DBOptions dbOptions = PredefinedOptions.DEFAULT.createDBOptions();
	dbOptions.setCreateIfMissing(true);
	ExecutionConfig executionConfig = new ExecutionConfig();
	final RocksDBKeyedStateBackend<Long> longHeapKeyedStateBackend =
		new RocksDBKeyedStateBackendBuilder<>(
			"no-op",
			ClassLoader.getSystemClassLoader(),
			temporaryFolder.getRoot(),
			dbOptions,
			stateName -> PredefinedOptions.DEFAULT.createColumnOptions(),
			mock(TaskKvStateRegistry.class),
			LongSerializer.INSTANCE,
			1,
			new KeyGroupRange(0, 0),
			executionConfig,
			TestLocalRecoveryConfig.disabled(),
			RocksDBStateBackend.PriorityQueueStateType.HEAP,
			TtlTimeProvider.DEFAULT,
			new UnregisteredMetricsGroup(),
			Collections.emptyList(),
			AbstractStateBackend.getCompressionDecorator(executionConfig),
			new CloseableRegistry()
		).build();
	longHeapKeyedStateBackend.setCurrentKey(key);

	final InternalListState<Long, VoidNamespace, Long> listState = longHeapKeyedStateBackend.createInternalState(VoidNamespaceSerializer.INSTANCE,
			new ListStateDescriptor<>("test", LongSerializer.INSTANCE));

	KvStateRequestSerializerTest.testListSerialization(key, listState);
	longHeapKeyedStateBackend.dispose();
}
 

@Override
public void open() throws Exception {
	super.open();
	this.state = getKeyedStateBackend().getPartitionedState(
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE,
			stateDescriptor);
}
 

/**
 * Tests a simple successful query via an EmbeddedChannel.
 */
@Test
public void testSimpleQuery() throws Exception {
	KvStateRegistry registry = new KvStateRegistry();
	AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	// Register state
	ValueStateDescriptor<Integer> desc = new ValueStateDescriptor<>("any", IntSerializer.INSTANCE);
	desc.setQueryable("vanilla");

	int numKeyGroups = 1;
	AbstractStateBackend abstractBackend = new MemoryStateBackend();
	DummyEnvironment dummyEnv = new DummyEnvironment("test", 1, 0);
	dummyEnv.setKvStateRegistry(registry);
	AbstractKeyedStateBackend<Integer> backend = createKeyedStateBackend(registry, numKeyGroups, abstractBackend, dummyEnv);

	final TestRegistryListener registryListener = new TestRegistryListener();
	registry.registerListener(dummyEnv.getJobID(), registryListener);

	// Update the KvState and request it
	int expectedValue = 712828289;

	int key = 99812822;
	backend.setCurrentKey(key);
	ValueState<Integer> state = backend.getPartitionedState(
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE,
			desc);

	state.update(expectedValue);

	byte[] serializedKeyAndNamespace = KvStateSerializer.serializeKeyAndNamespace(
			key,
			IntSerializer.INSTANCE,
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE);

	long requestId = Integer.MAX_VALUE + 182828L;

	assertTrue(registryListener.registrationName.equals("vanilla"));

	KvStateInternalRequest request = new KvStateInternalRequest(
			registryListener.kvStateId, serializedKeyAndNamespace);

	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), requestId, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
	buf.skipBytes(4); // skip frame length

	// Verify the response
	assertEquals(MessageType.REQUEST_RESULT, MessageSerializer.deserializeHeader(buf));
	long deserRequestId = MessageSerializer.getRequestId(buf);
	KvStateResponse response = serializer.deserializeResponse(buf);

	assertEquals(requestId, deserRequestId);

	int actualValue = KvStateSerializer.deserializeValue(response.getContent(), IntSerializer.INSTANCE);
	assertEquals(expectedValue, actualValue);

	assertEquals(stats.toString(), 1, stats.getNumRequests());

	// Wait for async successful request report
	long deadline = System.nanoTime() + TimeUnit.NANOSECONDS.convert(30, TimeUnit.SECONDS);
	while (stats.getNumSuccessful() != 1L && System.nanoTime() <= deadline) {
		Thread.sleep(10L);
	}

	assertEquals(stats.toString(), 1L, stats.getNumSuccessful());
}
 

/**
 * Tests that large responses are chunked.
 */
@Test
public void testChunkedResponse() throws Exception {
	KvStateRegistry registry = new KvStateRegistry();
	KvStateRequestStats stats = new AtomicKvStateRequestStats();

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	int numKeyGroups = 1;
	AbstractStateBackend abstractBackend = new MemoryStateBackend();
	DummyEnvironment dummyEnv = new DummyEnvironment("test", 1, 0);
	dummyEnv.setKvStateRegistry(registry);
	AbstractKeyedStateBackend<Integer> backend = createKeyedStateBackend(registry, numKeyGroups, abstractBackend, dummyEnv);

	final TestRegistryListener registryListener = new TestRegistryListener();
	registry.registerListener(dummyEnv.getJobID(), registryListener);

	// Register state
	ValueStateDescriptor<byte[]> desc = new ValueStateDescriptor<>("any", BytePrimitiveArraySerializer.INSTANCE);
	desc.setQueryable("vanilla");

	ValueState<byte[]> state = backend.getPartitionedState(
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE,
			desc);

	// Update KvState
	byte[] bytes = new byte[2 * channel.config().getWriteBufferHighWaterMark()];

	byte current = 0;
	for (int i = 0; i < bytes.length; i++) {
		bytes[i] = current++;
	}

	int key = 99812822;
	backend.setCurrentKey(key);
	state.update(bytes);

	// Request
	byte[] serializedKeyAndNamespace = KvStateSerializer.serializeKeyAndNamespace(
			key,
			IntSerializer.INSTANCE,
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE);

	long requestId = Integer.MAX_VALUE + 182828L;

	assertTrue(registryListener.registrationName.equals("vanilla"));

	KvStateInternalRequest request = new KvStateInternalRequest(registryListener.kvStateId, serializedKeyAndNamespace);
	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), requestId, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	Object msg = readInboundBlocking(channel);
	assertTrue("Not ChunkedByteBuf", msg instanceof ChunkedByteBuf);
	((ChunkedByteBuf) msg).close();
}
 

/**
 * Tests the failure response on a rejected execution, because the query executor has been closed.
 */
@Test
public void testQueryExecutorShutDown() throws Throwable {
	KvStateRegistry registry = new KvStateRegistry();
	AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();

	KvStateServerImpl localTestServer = new KvStateServerImpl(
			InetAddress.getLocalHost().getHostName(),
			Collections.singletonList(0).iterator(),
			1,
			1,
			new KvStateRegistry(),
			new DisabledKvStateRequestStats());

	localTestServer.start();
	localTestServer.shutdown();
	assertTrue(localTestServer.getQueryExecutor().isTerminated());

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(localTestServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	int numKeyGroups = 1;
	AbstractStateBackend abstractBackend = new MemoryStateBackend();
	DummyEnvironment dummyEnv = new DummyEnvironment("test", 1, 0);
	dummyEnv.setKvStateRegistry(registry);
	KeyedStateBackend<Integer> backend = createKeyedStateBackend(registry, numKeyGroups, abstractBackend, dummyEnv);

	final TestRegistryListener registryListener = new TestRegistryListener();
	registry.registerListener(dummyEnv.getJobID(), registryListener);

	// Register state
	ValueStateDescriptor<Integer> desc = new ValueStateDescriptor<>("any", IntSerializer.INSTANCE);
	desc.setQueryable("vanilla");

	backend.getPartitionedState(VoidNamespace.INSTANCE, VoidNamespaceSerializer.INSTANCE, desc);

	assertTrue(registryListener.registrationName.equals("vanilla"));

	KvStateInternalRequest request = new KvStateInternalRequest(registryListener.kvStateId, new byte[0]);
	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), 282872L, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
	buf.skipBytes(4); // skip frame length

	// Verify the response
	assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
	RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);
	buf.release();

	assertTrue(response.getCause().getMessage().contains("RejectedExecutionException"));

	assertEquals(1L, stats.getNumRequests());
	assertEquals(1L, stats.getNumFailed());

	localTestServer.shutdown();
}
 

/**
 * Tests the failure response on a failure on the {@link InternalKvState#getSerializedValue(byte[], TypeSerializer, TypeSerializer, TypeSerializer)} call.
 */
@Test
public void testFailureOnGetSerializedValue() throws Exception {
	KvStateRegistry registry = new KvStateRegistry();
	AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	// Failing KvState
	InternalKvState<Integer, VoidNamespace, Long> kvState =
			new InternalKvState<Integer, VoidNamespace, Long>() {
				@Override
				public TypeSerializer<Integer> getKeySerializer() {
					return IntSerializer.INSTANCE;
				}

				@Override
				public TypeSerializer<VoidNamespace> getNamespaceSerializer() {
					return VoidNamespaceSerializer.INSTANCE;
				}

				@Override
				public TypeSerializer<Long> getValueSerializer() {
					return LongSerializer.INSTANCE;
				}

				@Override
				public void setCurrentNamespace(VoidNamespace namespace) {
					// do nothing
				}

				@Override
				public byte[] getSerializedValue(
						final byte[] serializedKeyAndNamespace,
						final TypeSerializer<Integer> safeKeySerializer,
						final TypeSerializer<VoidNamespace> safeNamespaceSerializer,
						final TypeSerializer<Long> safeValueSerializer) throws Exception {
					throw new RuntimeException("Expected test Exception");
				}

				@Override
				public StateIncrementalVisitor<Integer, VoidNamespace, Long> getStateIncrementalVisitor(int recommendedMaxNumberOfReturnedRecords) {
					throw new UnsupportedOperationException();
				}

				@Override
				public void clear() {

				}
			};

	KvStateID kvStateId = registry.registerKvState(
			new JobID(),
			new JobVertexID(),
			new KeyGroupRange(0, 0),
			"vanilla",
			kvState);

	KvStateInternalRequest request = new KvStateInternalRequest(kvStateId, new byte[0]);
	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), 282872L, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
	buf.skipBytes(4); // skip frame length

	// Verify the response
	assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
	RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);
	buf.release();

	assertTrue(response.getCause().getMessage().contains("Expected test Exception"));

	assertEquals(1L, stats.getNumRequests());
	assertEquals(1L, stats.getNumFailed());
}
 

/**
 * Tests the failure response with {@link UnknownKeyOrNamespaceException} as cause
 * on queries for non-existing keys.
 */
@Test
public void testQueryUnknownKey() throws Exception {
	KvStateRegistry registry = new KvStateRegistry();
	AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	int numKeyGroups = 1;
	AbstractStateBackend abstractBackend = new MemoryStateBackend();
	DummyEnvironment dummyEnv = new DummyEnvironment("test", 1, 0);
	dummyEnv.setKvStateRegistry(registry);
	KeyedStateBackend<Integer> backend = createKeyedStateBackend(registry, numKeyGroups, abstractBackend, dummyEnv);

	final TestRegistryListener registryListener = new TestRegistryListener();
	registry.registerListener(dummyEnv.getJobID(), registryListener);

	// Register state
	ValueStateDescriptor<Integer> desc = new ValueStateDescriptor<>("any", IntSerializer.INSTANCE);
	desc.setQueryable("vanilla");

	backend.getPartitionedState(VoidNamespace.INSTANCE, VoidNamespaceSerializer.INSTANCE, desc);

	byte[] serializedKeyAndNamespace = KvStateSerializer.serializeKeyAndNamespace(
			1238283,
			IntSerializer.INSTANCE,
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE);

	long requestId = Integer.MAX_VALUE + 22982L;

	assertTrue(registryListener.registrationName.equals("vanilla"));

	KvStateInternalRequest request = new KvStateInternalRequest(registryListener.kvStateId, serializedKeyAndNamespace);
	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), requestId, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
	buf.skipBytes(4); // skip frame length

	// Verify the response
	assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
	RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);
	buf.release();

	assertEquals(requestId, response.getRequestId());

	assertTrue("Did not respond with expected failure cause", response.getCause() instanceof UnknownKeyOrNamespaceException);

	assertEquals(1L, stats.getNumRequests());
	assertEquals(1L, stats.getNumFailed());
}
 

/**
 * Tests a simple successful query via an EmbeddedChannel.
 */
@Test
public void testSimpleQuery() throws Exception {
	KvStateRegistry registry = new KvStateRegistry();
	AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	// Register state
	ValueStateDescriptor<Integer> desc = new ValueStateDescriptor<>("any", IntSerializer.INSTANCE);
	desc.setQueryable("vanilla");

	int numKeyGroups = 1;
	AbstractStateBackend abstractBackend = new MemoryStateBackend();
	DummyEnvironment dummyEnv = new DummyEnvironment("test", 1, 0);
	dummyEnv.setKvStateRegistry(registry);
	AbstractKeyedStateBackend<Integer> backend = createKeyedStateBackend(registry, numKeyGroups, abstractBackend, dummyEnv);

	final TestRegistryListener registryListener = new TestRegistryListener();
	registry.registerListener(dummyEnv.getJobID(), registryListener);

	// Update the KvState and request it
	int expectedValue = 712828289;

	int key = 99812822;
	backend.setCurrentKey(key);
	ValueState<Integer> state = backend.getPartitionedState(
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE,
			desc);

	state.update(expectedValue);

	byte[] serializedKeyAndNamespace = KvStateSerializer.serializeKeyAndNamespace(
			key,
			IntSerializer.INSTANCE,
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE);

	long requestId = Integer.MAX_VALUE + 182828L;

	assertTrue(registryListener.registrationName.equals("vanilla"));

	KvStateInternalRequest request = new KvStateInternalRequest(
			registryListener.kvStateId, serializedKeyAndNamespace);

	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), requestId, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
	buf.skipBytes(4); // skip frame length

	// Verify the response
	assertEquals(MessageType.REQUEST_RESULT, MessageSerializer.deserializeHeader(buf));
	long deserRequestId = MessageSerializer.getRequestId(buf);
	KvStateResponse response = serializer.deserializeResponse(buf);
	buf.release();

	assertEquals(requestId, deserRequestId);

	int actualValue = KvStateSerializer.deserializeValue(response.getContent(), IntSerializer.INSTANCE);
	assertEquals(expectedValue, actualValue);

	assertEquals(stats.toString(), 1, stats.getNumRequests());

	// Wait for async successful request report
	long deadline = System.nanoTime() + TimeUnit.NANOSECONDS.convert(30, TimeUnit.SECONDS);
	while (stats.getNumSuccessful() != 1L && System.nanoTime() <= deadline) {
		Thread.sleep(10L);
	}

	assertEquals(stats.toString(), 1L, stats.getNumSuccessful());
}
 

/**
 * Verifies that the serialization of a map using the given map state
 * matches the deserialization with {@link KvStateSerializer#deserializeList}.
 *
 * @param key
 * 		key of the map state
 * @param mapState
 * 		map state using the {@link VoidNamespace}, must also be a {@link InternalKvState} instance
 *
 * @throws Exception
 */
public static void testMapSerialization(
		final long key,
		final InternalMapState<Long, VoidNamespace, Long, String> mapState) throws Exception {

	TypeSerializer<Long> userKeySerializer = LongSerializer.INSTANCE;
	TypeSerializer<String> userValueSerializer = StringSerializer.INSTANCE;
	mapState.setCurrentNamespace(VoidNamespace.INSTANCE);

	// Map
	final int numElements = 10;

	final Map<Long, String> expectedValues = new HashMap<>();
	for (int i = 1; i <= numElements; i++) {
		final long value = ThreadLocalRandom.current().nextLong();
		expectedValues.put(value, Long.toString(value));
		mapState.put(value, Long.toString(value));
	}

	expectedValues.put(0L, null);
	mapState.put(0L, null);

	final byte[] serializedKey =
		KvStateSerializer.serializeKeyAndNamespace(
			key, LongSerializer.INSTANCE,
			VoidNamespace.INSTANCE, VoidNamespaceSerializer.INSTANCE);

	final byte[] serializedValues = mapState.getSerializedValue(
			serializedKey,
			mapState.getKeySerializer(),
			mapState.getNamespaceSerializer(),
			mapState.getValueSerializer());

	Map<Long, String> actualValues = KvStateSerializer.deserializeMap(serializedValues, userKeySerializer, userValueSerializer);
	assertEquals(expectedValues.size(), actualValues.size());
	for (Map.Entry<Long, String> actualEntry : actualValues.entrySet()) {
		assertEquals(expectedValues.get(actualEntry.getKey()), actualEntry.getValue());
	}

	// Single value
	ByteArrayOutputStream baos = new ByteArrayOutputStream();
	long expectedKey = ThreadLocalRandom.current().nextLong();
	String expectedValue = Long.toString(expectedKey);
	byte[] isNull = {0};

	baos.write(KvStateSerializer.serializeValue(expectedKey, userKeySerializer));
	baos.write(isNull);
	baos.write(KvStateSerializer.serializeValue(expectedValue, userValueSerializer));
	byte[] serializedValue = baos.toByteArray();

	Map<Long, String> actualValue = KvStateSerializer.deserializeMap(serializedValue, userKeySerializer, userValueSerializer);
	assertEquals(1, actualValue.size());
	assertEquals(expectedValue, actualValue.get(expectedKey));
}
 

/**
 * Verifies that the serialization of a map using the given map state
 * matches the deserialization with {@link KvStateSerializer#deserializeList}.
 *
 * @param key
 * 		key of the map state
 * @param mapState
 * 		map state using the {@link VoidNamespace}, must also be a {@link InternalKvState} instance
 *
 * @throws Exception
 */
public static void testMapSerialization(
		final long key,
		final InternalMapState<Long, VoidNamespace, Long, String> mapState) throws Exception {

	TypeSerializer<Long> userKeySerializer = LongSerializer.INSTANCE;
	TypeSerializer<String> userValueSerializer = StringSerializer.INSTANCE;
	mapState.setCurrentNamespace(VoidNamespace.INSTANCE);

	// Map
	final int numElements = 10;

	final Map<Long, String> expectedValues = new HashMap<>();
	for (int i = 1; i <= numElements; i++) {
		final long value = ThreadLocalRandom.current().nextLong();
		expectedValues.put(value, Long.toString(value));
		mapState.put(value, Long.toString(value));
	}

	expectedValues.put(0L, null);
	mapState.put(0L, null);

	final byte[] serializedKey =
		KvStateSerializer.serializeKeyAndNamespace(
			key, LongSerializer.INSTANCE,
			VoidNamespace.INSTANCE, VoidNamespaceSerializer.INSTANCE);

	final byte[] serializedValues = mapState.getSerializedValue(
			serializedKey,
			mapState.getKeySerializer(),
			mapState.getNamespaceSerializer(),
			mapState.getValueSerializer());

	Map<Long, String> actualValues = KvStateSerializer.deserializeMap(serializedValues, userKeySerializer, userValueSerializer);
	assertEquals(expectedValues.size(), actualValues.size());
	for (Map.Entry<Long, String> actualEntry : actualValues.entrySet()) {
		assertEquals(expectedValues.get(actualEntry.getKey()), actualEntry.getValue());
	}

	// Single value
	ByteArrayOutputStream baos = new ByteArrayOutputStream();
	long expectedKey = ThreadLocalRandom.current().nextLong();
	String expectedValue = Long.toString(expectedKey);
	byte[] isNull = {0};

	baos.write(KvStateSerializer.serializeValue(expectedKey, userKeySerializer));
	baos.write(isNull);
	baos.write(KvStateSerializer.serializeValue(expectedValue, userValueSerializer));
	byte[] serializedValue = baos.toByteArray();

	Map<Long, String> actualValue = KvStateSerializer.deserializeMap(serializedValue, userKeySerializer, userValueSerializer);
	assertEquals(1, actualValue.size());
	assertEquals(expectedValue, actualValue.get(expectedKey));
}
 

/**
 * Tests map serialization and deserialization match.
 *
 * @see KvStateRequestSerializerTest#testMapSerialization()
 * KvStateRequestSerializerTest#testMapSerialization() using the heap state back-end
 * test
 */
@Test
public void testMapSerialization() throws Exception {
	final long key = 0L;

	// objects for RocksDB state list serialisation
	DBOptions dbOptions = PredefinedOptions.DEFAULT.createDBOptions();
	dbOptions.setCreateIfMissing(true);
	ExecutionConfig executionConfig = new ExecutionConfig();
	final RocksDBKeyedStateBackend<Long> longHeapKeyedStateBackend =
		new RocksDBKeyedStateBackendBuilder<>(
			"no-op",
			ClassLoader.getSystemClassLoader(),
			temporaryFolder.getRoot(),
			dbOptions,
			stateName -> PredefinedOptions.DEFAULT.createColumnOptions(),
			mock(TaskKvStateRegistry.class),
			LongSerializer.INSTANCE,
			1,
			new KeyGroupRange(0, 0),
			executionConfig,
			TestLocalRecoveryConfig.disabled(),
			RocksDBStateBackend.PriorityQueueStateType.HEAP,
			TtlTimeProvider.DEFAULT,
			new UnregisteredMetricsGroup(),
			Collections.emptyList(),
			AbstractStateBackend.getCompressionDecorator(executionConfig),
			new CloseableRegistry()
		).build();
	longHeapKeyedStateBackend.setCurrentKey(key);

	final InternalMapState<Long, VoidNamespace, Long, String> mapState =
			(InternalMapState<Long, VoidNamespace, Long, String>)
					longHeapKeyedStateBackend.getPartitionedState(
							VoidNamespace.INSTANCE,
							VoidNamespaceSerializer.INSTANCE,
							new MapStateDescriptor<>("test", LongSerializer.INSTANCE, StringSerializer.INSTANCE));

	KvStateRequestSerializerTest.testMapSerialization(key, mapState);
	longHeapKeyedStateBackend.dispose();
}
 

/**
 * Tests the failure response with {@link UnknownKeyOrNamespaceException} as cause
 * on queries for non-existing keys.
 */
@Test
public void testQueryUnknownKey() throws Exception {
	KvStateRegistry registry = new KvStateRegistry();
	AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	int numKeyGroups = 1;
	AbstractStateBackend abstractBackend = new MemoryStateBackend();
	DummyEnvironment dummyEnv = new DummyEnvironment("test", 1, 0);
	dummyEnv.setKvStateRegistry(registry);
	KeyedStateBackend<Integer> backend = createKeyedStateBackend(registry, numKeyGroups, abstractBackend, dummyEnv);

	final TestRegistryListener registryListener = new TestRegistryListener();
	registry.registerListener(dummyEnv.getJobID(), registryListener);

	// Register state
	ValueStateDescriptor<Integer> desc = new ValueStateDescriptor<>("any", IntSerializer.INSTANCE);
	desc.setQueryable("vanilla");

	backend.getPartitionedState(VoidNamespace.INSTANCE, VoidNamespaceSerializer.INSTANCE, desc);

	byte[] serializedKeyAndNamespace = KvStateSerializer.serializeKeyAndNamespace(
			1238283,
			IntSerializer.INSTANCE,
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE);

	long requestId = Integer.MAX_VALUE + 22982L;

	assertTrue(registryListener.registrationName.equals("vanilla"));

	KvStateInternalRequest request = new KvStateInternalRequest(registryListener.kvStateId, serializedKeyAndNamespace);
	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), requestId, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
	buf.skipBytes(4); // skip frame length

	// Verify the response
	assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
	RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);

	assertEquals(requestId, response.getRequestId());

	assertTrue("Did not respond with expected failure cause", response.getCause() instanceof UnknownKeyOrNamespaceException);

	assertEquals(1L, stats.getNumRequests());
	assertEquals(1L, stats.getNumFailed());
}
 

/**
 * Tests that large responses are chunked.
 */
@Test
public void testChunkedResponse() throws Exception {
	KvStateRegistry registry = new KvStateRegistry();
	KvStateRequestStats stats = new AtomicKvStateRequestStats();

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	int numKeyGroups = 1;
	AbstractStateBackend abstractBackend = new MemoryStateBackend();
	DummyEnvironment dummyEnv = new DummyEnvironment("test", 1, 0);
	dummyEnv.setKvStateRegistry(registry);
	AbstractKeyedStateBackend<Integer> backend = createKeyedStateBackend(registry, numKeyGroups, abstractBackend, dummyEnv);

	final TestRegistryListener registryListener = new TestRegistryListener();
	registry.registerListener(dummyEnv.getJobID(), registryListener);

	// Register state
	ValueStateDescriptor<byte[]> desc = new ValueStateDescriptor<>("any", BytePrimitiveArraySerializer.INSTANCE);
	desc.setQueryable("vanilla");

	ValueState<byte[]> state = backend.getPartitionedState(
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE,
			desc);

	// Update KvState
	byte[] bytes = new byte[2 * channel.config().getWriteBufferHighWaterMark()];

	byte current = 0;
	for (int i = 0; i < bytes.length; i++) {
		bytes[i] = current++;
	}

	int key = 99812822;
	backend.setCurrentKey(key);
	state.update(bytes);

	// Request
	byte[] serializedKeyAndNamespace = KvStateSerializer.serializeKeyAndNamespace(
			key,
			IntSerializer.INSTANCE,
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE);

	long requestId = Integer.MAX_VALUE + 182828L;

	assertTrue(registryListener.registrationName.equals("vanilla"));

	KvStateInternalRequest request = new KvStateInternalRequest(registryListener.kvStateId, serializedKeyAndNamespace);
	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), requestId, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	Object msg = readInboundBlocking(channel);
	assertTrue("Not ChunkedByteBuf", msg instanceof ChunkedByteBuf);
}
 

/**
 * Tests the failure response on a rejected execution, because the query executor has been closed.
 */
@Test
public void testQueryExecutorShutDown() throws Throwable {
	KvStateRegistry registry = new KvStateRegistry();
	AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();

	KvStateServerImpl localTestServer = new KvStateServerImpl(
			InetAddress.getLocalHost(),
			Collections.singletonList(0).iterator(),
			1,
			1,
			new KvStateRegistry(),
			new DisabledKvStateRequestStats());

	localTestServer.start();
	localTestServer.shutdown();
	assertTrue(localTestServer.getQueryExecutor().isTerminated());

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(localTestServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	int numKeyGroups = 1;
	AbstractStateBackend abstractBackend = new MemoryStateBackend();
	DummyEnvironment dummyEnv = new DummyEnvironment("test", 1, 0);
	dummyEnv.setKvStateRegistry(registry);
	KeyedStateBackend<Integer> backend = createKeyedStateBackend(registry, numKeyGroups, abstractBackend, dummyEnv);

	final TestRegistryListener registryListener = new TestRegistryListener();
	registry.registerListener(dummyEnv.getJobID(), registryListener);

	// Register state
	ValueStateDescriptor<Integer> desc = new ValueStateDescriptor<>("any", IntSerializer.INSTANCE);
	desc.setQueryable("vanilla");

	backend.getPartitionedState(VoidNamespace.INSTANCE, VoidNamespaceSerializer.INSTANCE, desc);

	assertTrue(registryListener.registrationName.equals("vanilla"));

	KvStateInternalRequest request = new KvStateInternalRequest(registryListener.kvStateId, new byte[0]);
	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), 282872L, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
	buf.skipBytes(4); // skip frame length

	// Verify the response
	assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
	RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);

	assertTrue(response.getCause().getMessage().contains("RejectedExecutionException"));

	assertEquals(1L, stats.getNumRequests());
	assertEquals(1L, stats.getNumFailed());

	localTestServer.shutdown();
}
 

/**
 * Tests the failure response on a failure on the {@link InternalKvState#getSerializedValue(byte[], TypeSerializer, TypeSerializer, TypeSerializer)} call.
 */
@Test
public void testFailureOnGetSerializedValue() throws Exception {
	KvStateRegistry registry = new KvStateRegistry();
	AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	// Failing KvState
	InternalKvState<Integer, VoidNamespace, Long> kvState =
			new InternalKvState<Integer, VoidNamespace, Long>() {
				@Override
				public TypeSerializer<Integer> getKeySerializer() {
					return IntSerializer.INSTANCE;
				}

				@Override
				public TypeSerializer<VoidNamespace> getNamespaceSerializer() {
					return VoidNamespaceSerializer.INSTANCE;
				}

				@Override
				public TypeSerializer<Long> getValueSerializer() {
					return LongSerializer.INSTANCE;
				}

				@Override
				public void setCurrentNamespace(VoidNamespace namespace) {
					// do nothing
				}

				@Override
				public byte[] getSerializedValue(
						final byte[] serializedKeyAndNamespace,
						final TypeSerializer<Integer> safeKeySerializer,
						final TypeSerializer<VoidNamespace> safeNamespaceSerializer,
						final TypeSerializer<Long> safeValueSerializer) throws Exception {
					throw new RuntimeException("Expected test Exception");
				}

				@Override
				public StateIncrementalVisitor<Integer, VoidNamespace, Long> getStateIncrementalVisitor(int recommendedMaxNumberOfReturnedRecords) {
					throw new UnsupportedOperationException();
				}

				@Override
				public void clear() {

				}
			};

	KvStateID kvStateId = registry.registerKvState(
			new JobID(),
			new JobVertexID(),
			new KeyGroupRange(0, 0),
			"vanilla",
			kvState);

	KvStateInternalRequest request = new KvStateInternalRequest(kvStateId, new byte[0]);
	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), 282872L, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
	buf.skipBytes(4); // skip frame length

	// Verify the response
	assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
	RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);

	assertTrue(response.getCause().getMessage().contains("Expected test Exception"));

	assertEquals(1L, stats.getNumRequests());
	assertEquals(1L, stats.getNumFailed());
}
 

/**
 * Tests the failure response with {@link UnknownKeyOrNamespaceException} as cause
 * on queries for non-existing keys.
 */
@Test
public void testQueryUnknownKey() throws Exception {
	KvStateRegistry registry = new KvStateRegistry();
	AtomicKvStateRequestStats stats = new AtomicKvStateRequestStats();

	MessageSerializer<KvStateInternalRequest, KvStateResponse> serializer =
			new MessageSerializer<>(new KvStateInternalRequest.KvStateInternalRequestDeserializer(), new KvStateResponse.KvStateResponseDeserializer());

	KvStateServerHandler handler = new KvStateServerHandler(testServer, registry, serializer, stats);
	EmbeddedChannel channel = new EmbeddedChannel(getFrameDecoder(), handler);

	int numKeyGroups = 1;
	AbstractStateBackend abstractBackend = new MemoryStateBackend();
	DummyEnvironment dummyEnv = new DummyEnvironment("test", 1, 0);
	dummyEnv.setKvStateRegistry(registry);
	KeyedStateBackend<Integer> backend = createKeyedStateBackend(registry, numKeyGroups, abstractBackend, dummyEnv);

	final TestRegistryListener registryListener = new TestRegistryListener();
	registry.registerListener(dummyEnv.getJobID(), registryListener);

	// Register state
	ValueStateDescriptor<Integer> desc = new ValueStateDescriptor<>("any", IntSerializer.INSTANCE);
	desc.setQueryable("vanilla");

	backend.getPartitionedState(VoidNamespace.INSTANCE, VoidNamespaceSerializer.INSTANCE, desc);

	byte[] serializedKeyAndNamespace = KvStateSerializer.serializeKeyAndNamespace(
			1238283,
			IntSerializer.INSTANCE,
			VoidNamespace.INSTANCE,
			VoidNamespaceSerializer.INSTANCE);

	long requestId = Integer.MAX_VALUE + 22982L;

	assertTrue(registryListener.registrationName.equals("vanilla"));

	KvStateInternalRequest request = new KvStateInternalRequest(registryListener.kvStateId, serializedKeyAndNamespace);
	ByteBuf serRequest = MessageSerializer.serializeRequest(channel.alloc(), requestId, request);

	// Write the request and wait for the response
	channel.writeInbound(serRequest);

	ByteBuf buf = (ByteBuf) readInboundBlocking(channel);
	buf.skipBytes(4); // skip frame length

	// Verify the response
	assertEquals(MessageType.REQUEST_FAILURE, MessageSerializer.deserializeHeader(buf));
	RequestFailure response = MessageSerializer.deserializeRequestFailure(buf);

	assertEquals(requestId, response.getRequestId());

	assertTrue("Did not respond with expected failure cause", response.getCause() instanceof UnknownKeyOrNamespaceException);

	assertEquals(1L, stats.getNumRequests());
	assertEquals(1L, stats.getNumFailed());
}