Kafka Streams：状态存储分区错误

Question

定义了一个自定义存储，用于自定义 Transformer（参考下面）。

https://github.com/apache/kafka/blob/trunk/streams/examples/src/main/java/org/apache/kafka/streams/examples/wordcount/WordCountProcessorDemo.java

public class KafkaStream {
    public static void main(String[] args) {

        StateStoreSupplier houseStore = Stores.create("HOUSE").withKeys(Serdes.String()).withValues(houseSerde).persistent().build();
        KStreamBuilder kstreamBuilder = new KStreamBuilder();
        kstreamBuilder.addStateStore(houseStore);
        .
        .
        .

        KStream<String, String> testStream = kstreamBuilder.stream(Serdes.String(), Serdes.String(), "test");
        testStream.transform(HourlyDetail::new, houseStore.name());
        .
        .
        .
    }
}

class HouseDetail implements Transformer<String, String, KeyValue<String, House>> {
    @SuppressWarnings("unchecked")
    @Override
    public void init(ProcessorContext context) {
        this.usageStore = (KeyValueStore<String, House>) context.getStateStore("HOUSE");
    }
    .
    .
    .
}

我得到以下异常。不确定，为什么使用单个分区和单个复制创建内部主题“test_01-HOUSE-changelog”，而不是源分区“test”中的 2 个分区。这里缺少什么？

[2018-05-14 23:38:09,391] ERROR stream-thread [StreamThread-1] Failed to create an active task 0_1:  (org.apache.kafka.streams.processor.internals.StreamThread:666)
org.apache.kafka.streams.errors.StreamsException: task [0_1] Store HOUSE's change log (test_01-HOUSE-changelog) does not contain partition 1
        at org.apache.kafka.streams.processor.internals.ProcessorStateManager.register(ProcessorStateManager.java:185)
        at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.register(ProcessorContextImpl.java:123)
        at org.apache.kafka.streams.state.internals.RocksDBStore.init(RocksDBStore.java:169)
        at org.apache.kafka.streams.state.internals.MeteredKeyValueStore.init(MeteredKeyValueStore.java:85)
        at org.apache.kafka.streams.processor.internals.AbstractTask.initializeStateStores(AbstractTask.java:81)
        at org.apache.kafka.streams.processor.internals.StreamTask.<init>(StreamTask.java:119)
        at org.apache.kafka.streams.processor.internals.StreamThread.createStreamTask(StreamThread.java:633)
        at org.apache.kafka.streams.processor.internals.StreamThread.addStreamTasks(StreamThread.java:660)
        at org.apache.kafka.streams.processor.internals.StreamThread.access$100(StreamThread.java:69)
        at org.apache.kafka.streams.processor.internals.StreamThread$1.onPartitionsAssigned(StreamThread.java:124)
        at org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.onJoinComplete(ConsumerCoordinator.java:228)
        at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.joinGroupIfNeeded(AbstractCoordinator.java:313)
        at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.ensureActiveGroup(AbstractCoordinator.java:277)
        at org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.poll(ConsumerCoordinator.java:259)
        at org.apache.kafka.clients.consumer.KafkaConsumer.pollOnce(KafkaConsumer.java:1013)
        at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:979)
        at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:407)
        at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:242)

$ ./kafka-topics.sh --zookeeper localhost:2181 --topic test --describe                                                      
Topic:test  PartitionCount:2        ReplicationFactor:3     Configs:
   Topic: test Partition: 0    Leader: 1001    Replicas: 1001,1002,1003        Isr: 1002,1001,1003
   Topic: test Partition: 1    Leader: 1002    Replicas: 1002,1003,1001        Isr: 1002,1001,1003

$ ./kafka-topics.sh --zookeeper localhost:2181 --topic test_01-HOUSE-changelog --describe                                    
Topic:test_01-HOUSE-changelog        PartitionCount:1        ReplicationFactor:1     Configs:
   Topic: test_01-HOUSE-changelog       Partition: 0    Leader: 1001    Replicas: 1001  Isr: 1001

禁用自动创建主题后出现异常

[2018-05-17 14:25:41,114] ERROR stream-thread [StreamThread-1] Failed to create an active task 0_0:  (org.apache.kafka.streams.processor.internals.StreamThread:666)
org.apache.kafka.streams.errors.StreamsException: task [0_0] Could not find partition info for topic: test_01-HOUSE-changelog
        at org.apache.kafka.streams.processor.internals.ProcessorStateManager.register(ProcessorStateManager.java:174)
        at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.register(ProcessorContextImpl.java:123)
        at org.apache.kafka.streams.state.internals.RocksDBStore.init(RocksDBStore.java:169)
        at org.apache.kafka.streams.state.internals.MeteredKeyValueStore.init(MeteredKeyValueStore.java:85)
        at org.apache.kafka.streams.processor.internals.AbstractTask.initializeStateStores(AbstractTask.java:81)
        at org.apache.kafka.streams.processor.internals.StreamTask.<init>(StreamTask.java:119)
        at org.apache.kafka.streams.processor.internals.StreamThread.createStreamTask(StreamThread.java:633)
        at org.apache.kafka.streams.processor.internals.StreamThread.addStreamTasks(StreamThread.java:660)
        at org.apache.kafka.streams.processor.internals.StreamThread.access$100(StreamThread.java:69)
        at org.apache.kafka.streams.processor.internals.StreamThread$1.onPartitionsAssigned(StreamThread.java:124)
        at org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.onJoinComplete(ConsumerCoordinator.java:228)
        at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.joinGroupIfNeeded(AbstractCoordinator.java:313)
        at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.ensureActiveGroup(AbstractCoordinator.java:277)
        at org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.poll(ConsumerCoordinator.java:259)
        at org.apache.kafka.clients.consumer.KafkaConsumer.pollOnce(KafkaConsumer.java:1013)
        at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:979)
        at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:407)
        at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:242)

Answer 1

如果主题存在一个分区，Kafka Streams 不会自动更改分区数。目前尚不清楚为什么该主题是使用您提供的信息中的一个分区创建的。一种可能性是，当您第一次启动应用程序时，您的输入主题有一个分区，后来您向输入主题添加了第二个分区。

您需要使用文档中描述的应用程序重置工具清理应用程序（注意，这是一个两步过程）：https://docs.confluent.io/current/streams/developer-guide/app-reset-tool.html