Details
Description
StreamThread dies with the following exception:
java.lang.IllegalStateException: Consumer is not subscribed to any topics or assigned any partitions at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1206) at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1199) at org.apache.kafka.streams.processor.internals.StreamThread.maybeUpdateStandbyTasks(StreamThread.java:1126) at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:923) at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:805) at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:774)
The reason is that the restore consumer is not subscribed to any topic. This happens when a StreamThread gets assigned standby tasks for sub-topologies with just state stores with disabled logging.
To reproduce the bug start two applications with one StreamThread and one standby replica each and the following topology. The input topic should have two partitions:
final StreamsBuilder builder = new StreamsBuilder(); final String stateStoreName = "myTransformState"; final StoreBuilder<KeyValueStore<Integer, Integer>> keyValueStoreBuilder = Stores.keyValueStoreBuilder(Stores.persistentKeyValueStore(stateStoreName), Serdes.Integer(), Serdes.Integer()) .withLoggingDisabled(); builder.addStateStore(keyValueStoreBuilder); builder.stream(INPUT_TOPIC, Consumed.with(Serdes.Integer(), Serdes.Integer())) .transform(() -> new Transformer<Integer, Integer, KeyValue<Integer, Integer>>() { private KeyValueStore<Integer, Integer> state; @SuppressWarnings("unchecked") @Override public void init(final ProcessorContext context) { state = (KeyValueStore<Integer, Integer>) context.getStateStore(stateStoreName); } @Override public KeyValue<Integer, Integer> transform(final Integer key, final Integer value) { final KeyValue<Integer, Integer> result = new KeyValue<>(key, value); return result; } @Override public void close() {} }, stateStoreName) .to(OUTPUT_TOPIC);
Both StreamThreads should die with the above exception.
The root cause is that standby tasks are created although all state stores of the sub-topology have logging disabled.