cadonna commented on a change in pull request #9273: URL: https://github.com/apache/kafka/pull/9273#discussion_r500832713
########## File path: streams/src/main/java/org/apache/kafka/streams/errors/StreamsUncaughtExceptionHandler.java ########## @@ -0,0 +1,49 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.kafka.streams.errors; + +public interface StreamsUncaughtExceptionHandler { + /** + * Inspect a record and the exception received. + * @param exception the actual exception + */ + StreamsUncaughtExceptionHandler.StreamsUncaughtExceptionHandlerResponse handle(final Throwable exception); + + /** + * Enumeration that describes the response from the exception handler. + */ + enum StreamsUncaughtExceptionHandlerResponse { + + Review comment: nit: I would delete these two line ########## File path: streams/src/main/java/org/apache/kafka/streams/processor/internals/StreamThread.java ########## @@ -936,6 +968,8 @@ public void shutdown() { } } + + Review comment: Please remove ########## File path: streams/src/main/java/org/apache/kafka/streams/KafkaStreams.java ########## @@ -436,6 +496,8 @@ private void maybeSetError() { } if (setState(State.ERROR)) { + metrics.close(); Review comment: I think there is a misunderstanding regarding `metrics.close()`. We should not close the metrics here. We should stop the `rocksDBMetricsRecordingService` with `rocksDBMetricsRecordingService.shutdownNow()`. That is what the KIP says. ########## File path: streams/src/main/java/org/apache/kafka/streams/processor/internals/StreamThread.java ########## @@ -566,10 +572,36 @@ void runLoop() { } } catch (final TaskMigratedException e) { handleTaskMigrated(e); + } catch (final Exception e) { + if (streamsUncaughtExceptionHandler != null) { Review comment: I would avoid this `null` check by setting the `streamsUncaughtExceptionHandler` by default to the default uncaught exception handler. ########## File path: streams/src/main/java/org/apache/kafka/streams/processor/internals/StreamThread.java ########## @@ -384,9 +390,8 @@ public static StreamThread create(final InternalTopologyBuilder builder, builder, threadId, logContext, - assignmentErrorCode, - nextScheduledRebalanceMs - ); + nextScheduledRebalanceMs, + assignmentErrorCode); Review comment: The closing parenthesis should be in a new line. ```suggestion assignmentErrorCode ); ``` ########## File path: streams/src/main/java/org/apache/kafka/streams/errors/StreamsUncaughtExceptionHandler.java ########## @@ -0,0 +1,49 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.kafka.streams.errors; + +public interface StreamsUncaughtExceptionHandler { + /** + * Inspect a record and the exception received. + * @param exception the actual exception + */ + StreamsUncaughtExceptionHandler.StreamsUncaughtExceptionHandlerResponse handle(final Throwable exception); + + /** + * Enumeration that describes the response from the exception handler. + */ + enum StreamsUncaughtExceptionHandlerResponse { + + + SHUTDOWN_STREAM_THREAD(0, "SHUTDOWN_STREAM_THREAD"), +// REPLACE_STREAM_THREAD(1, "REPLACE_STREAM_THREAD"), + SHUTDOWN_KAFKA_STREAMS_CLIENT(2, "SHUTDOWN_KAFKA_STREAMS_CLIENT"), + SHUTDOWN_KAFKA_STREAMS_APPLICATION(3, "SHUTDOWN_KAFKA_STREAMS_APPLICATION"); + Review comment: nit: I would delete this line ########## File path: streams/src/main/java/org/apache/kafka/streams/processor/internals/StreamThread.java ########## @@ -528,12 +536,10 @@ public void run() { throw e; } } - - log.error("Encountered the following exception during processing " + - "and the thread is going to shut down: ", e); throw e; } finally { completeShutdown(cleanRun); + Review comment: Why did you add this line? I would remove it. ########## File path: streams/src/main/java/org/apache/kafka/streams/processor/internals/StreamsPartitionAssignor.java ########## @@ -342,6 +347,13 @@ public GroupAssignment assign(final Cluster metadata, final GroupSubscription gr // the maximum of the depending sub-topologies source topics' number of partitions final Map<Integer, TopicsInfo> topicGroups = taskManager.builder().topicGroups(); + if (shutdownRequested) { + return new GroupAssignment( + errorAssignment(clientMetadataMap, + AssignorError.SHUTDOWN_REQUESTED.code()) Review comment: You can put all of it in one line. ```suggestion return new GroupAssignment(errorAssignment(clientMetadataMap, AssignorError.SHUTDOWN_REQUESTED.code())); ``` ########## File path: streams/src/main/java/org/apache/kafka/streams/processor/internals/StreamsPartitionAssignor.java ########## @@ -342,6 +347,13 @@ public GroupAssignment assign(final Cluster metadata, final GroupSubscription gr // the maximum of the depending sub-topologies source topics' number of partitions final Map<Integer, TopicsInfo> topicGroups = taskManager.builder().topicGroups(); + if (shutdownRequested) { Review comment: Is there a reason, that prevents you to check the `shutdownRequested` flag in the first step of `Step One`? ########## File path: streams/src/main/java/org/apache/kafka/streams/KafkaStreams.java ########## @@ -364,6 +370,73 @@ public void setUncaughtExceptionHandler(final Thread.UncaughtExceptionHandler eh } } + /** + * Set the handler invoked when a {@link StreamsConfig#NUM_STREAM_THREADS_CONFIG internal thread} + * throws an unexpected exception. + * These might be exceptions indicating rare bugs in Kafka Streams, or they + * might be exceptions thrown by your code, for example a NullPointerException thrown from your processor + * logic. + * <p> + * Note, this handler must be threadsafe, since it will be shared among all threads, and invoked from any + * thread that encounters such an exception. + * + * @param streamsUncaughtExceptionHandler the uncaught exception handler of type {@link StreamsUncaughtExceptionHandler} for all internal threads; {@code null} deletes the current handler + * @throws IllegalStateException if this {@code KafkaStreams} instance is not in state {@link State#CREATED CREATED}. + */ + public void setUncaughtExceptionHandler(final StreamsUncaughtExceptionHandler streamsUncaughtExceptionHandler) { + final StreamsUncaughtExceptionHandler handler = throwable -> handleStreamsUncaughtException(throwable, streamsUncaughtExceptionHandler); + synchronized (stateLock) { + if (state == State.CREATED) { + for (final StreamThread thread : threads) { + if (streamsUncaughtExceptionHandler != null) { Review comment: I think it is better to throw if the passed in exception handler is `null` and set the default uncaught exception handler in the `StreamThread` constructor. ########## File path: streams/src/main/java/org/apache/kafka/streams/KafkaStreams.java ########## @@ -364,6 +370,73 @@ public void setUncaughtExceptionHandler(final Thread.UncaughtExceptionHandler eh } } + /** + * Set the handler invoked when a {@link StreamsConfig#NUM_STREAM_THREADS_CONFIG internal thread} + * throws an unexpected exception. + * These might be exceptions indicating rare bugs in Kafka Streams, or they + * might be exceptions thrown by your code, for example a NullPointerException thrown from your processor + * logic. + * <p> + * Note, this handler must be threadsafe, since it will be shared among all threads, and invoked from any + * thread that encounters such an exception. + * + * @param streamsUncaughtExceptionHandler the uncaught exception handler of type {@link StreamsUncaughtExceptionHandler} for all internal threads; {@code null} deletes the current handler + * @throws IllegalStateException if this {@code KafkaStreams} instance is not in state {@link State#CREATED CREATED}. + */ + public void setUncaughtExceptionHandler(final StreamsUncaughtExceptionHandler streamsUncaughtExceptionHandler) { + final StreamsUncaughtExceptionHandler handler = throwable -> handleStreamsUncaughtException(throwable, streamsUncaughtExceptionHandler); + synchronized (stateLock) { + if (state == State.CREATED) { + for (final StreamThread thread : threads) { + if (streamsUncaughtExceptionHandler != null) { + thread.setStreamsUncaughtExceptionHandler(handler); + } else { + final StreamsUncaughtExceptionHandler defaultHandler = exception -> + StreamsUncaughtExceptionHandler.StreamsUncaughtExceptionHandlerResponse.SHUTDOWN_STREAM_THREAD; + thread.setStreamsUncaughtExceptionHandler(defaultHandler); + } + } + } else { + throw new IllegalStateException("Can only set UncaughtExceptionHandler in CREATED state. " + + "Current state is: " + state); + } + } + } + + private StreamsUncaughtExceptionHandler.StreamsUncaughtExceptionHandlerResponse handleStreamsUncaughtException(final Throwable e, + final StreamsUncaughtExceptionHandler streamsUncaughtExceptionHandler) { + final StreamsUncaughtExceptionHandler.StreamsUncaughtExceptionHandlerResponse action = streamsUncaughtExceptionHandler.handle(e); + switch (action) { + case SHUTDOWN_STREAM_THREAD: + log.error("Encountered the following exception during processing " + + "and the thread is going to shut down: ", e); + break; Review comment: What about not considering this case here and logging and throwing the exception where the handler is called in `StreamThread`. So we would have all handling logic for this case in one place. ########## File path: streams/src/test/java/org/apache/kafka/streams/KafkaStreamsTest.java ########## @@ -617,7 +619,19 @@ public void shouldThrowExceptionSettingUncaughtExceptionHandlerNotInCreateState( final KafkaStreams streams = new KafkaStreams(getBuilderWithSource().build(), props, supplier, time); streams.start(); try { - streams.setUncaughtExceptionHandler(null); + streams.setUncaughtExceptionHandler((Thread.UncaughtExceptionHandler) null); + fail("Should throw IllegalStateException"); + } catch (final IllegalStateException e) { + // expected + } + } Review comment: This test misses the verification whether the `StreamThread#setUncaughtExceptionHandler()` is called. This has been missing also before this PR. ########## File path: streams/src/test/java/org/apache/kafka/streams/processor/internals/StreamThreadTest.java ########## @@ -226,8 +226,8 @@ private StreamThread createStreamThread(@SuppressWarnings("SameParameterValue") 0, stateDirectory, new MockStateRestoreListener(), - threadIdx - ); + threadIdx, + new AtomicInteger()); Review comment: The closing parenthesis should go to new line: ```suggestion new AtomicInteger() ); ``` Please check all your changes in this file. ########## File path: streams/src/test/java/org/apache/kafka/streams/KafkaStreamsTest.java ########## @@ -617,7 +619,19 @@ public void shouldThrowExceptionSettingUncaughtExceptionHandlerNotInCreateState( final KafkaStreams streams = new KafkaStreams(getBuilderWithSource().build(), props, supplier, time); streams.start(); try { - streams.setUncaughtExceptionHandler(null); + streams.setUncaughtExceptionHandler((Thread.UncaughtExceptionHandler) null); + fail("Should throw IllegalStateException"); + } catch (final IllegalStateException e) { + // expected + } + } + + @Test + public void shouldThrowExceptionSettingStreamsUncaughtExceptionHandlerNotInCreateState() { Review comment: This test misses the verification whether the `StreamThread#setStreamsUncaughtExceptionHandler()` is called. Additionally, a test is missing that tests when `null` is passed into `KafkaStreams#setUncaughtExceptionHandler()`. ########## File path: streams/src/test/java/org/apache/kafka/streams/processor/internals/StreamThreadTest.java ########## @@ -932,9 +929,8 @@ public void shouldShutdownTaskManagerOnClose() { internalTopologyBuilder, CLIENT_ID, new LogContext(""), - new AtomicInteger(), - new AtomicLong(Long.MAX_VALUE) - ).updateThreadMetadata(getSharedAdminClientId(CLIENT_ID)); + new AtomicLong(Long.MAX_VALUE), + new AtomicInteger()).updateThreadMetadata(getSharedAdminClientId(CLIENT_ID)); Review comment: Also here it should be: ```suggestion new AtomicInteger() ).updateThreadMetadata(getSharedAdminClientId(CLIENT_ID)); ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. 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