kafka流应用程序显示,每次重新启动时,将分区event-x的偏移量重置为偏移量0

ukqbszuj  于 2021-06-04  发布在  Kafka
关注(0)|答案(1)|浏览(441)

我有一个spring cloud stream kafka流应用程序,它读取一个主题(事件)并执行一个简单的处理:

@Configuration
class EventKStreamConfiguration {

    private val logger = LoggerFactory.getLogger(javaClass)

    @StreamListener
    fun process(@Input("event") eventStream: KStream<String, EventReceived>) {

        eventStream.foreach { key, value ->
            logger.info("--------> Processing Event {}", value)
            // Save in DB
        }
    }
}

此应用程序使用来自confluent cloud的kafka环境,其事件主题具有6个分区。完整配置为:

spring:
  application:
    name: events-processor
  cloud:
    stream:
      schema-registry-client:
        endpoint: ${schema-registry-url:http://localhost:8081}
      kafka:
        streams:
          binder:
            brokers: ${kafka-brokers:localhost}
            configuration:
              application:
                id: ${spring.application.name}
              default:
                key:
                  serde: org.apache.kafka.common.serialization.Serdes$StringSerde
              schema:
                registry:
                  url: ${spring.cloud.stream.schema-registry-client.endpoint}
              value:
                subject:
                  name:
                    strategy: io.confluent.kafka.serializers.subject.RecordNameStrategy
              processing:
                guarantee: exactly_once
          bindings:
            event:
              consumer:
                valueSerde: io.confluent.kafka.streams.serdes.avro.SpecificAvroSerde
      bindings:
        event:
          destination: event

  data:
    mongodb:
      uri: ${mongodb-uri:mongodb://localhost/test}

server:
  port: 8085

logging:
  level:
    org.springframework.kafka.config: debug

---

spring:
  profiles: confluent-cloud
  cloud:
    stream:
      kafka:
        streams:
          binder:
            autoCreateTopics: false
            configuration:
              retry:
                backoff:
                  ms: 500
              security:
                protocol: SASL_SSL
              sasl:
                mechanism: PLAIN
                jaas:
                  config: xxx
              basic:
                auth:
                  credentials:
                    source: USER_INFO
              schema:
                registry:
                  basic:
                    auth:
                      user:
                        info: yyy

kstream正在正确处理消息。如果我重新启动应用程序,它们不会被重新处理。注意:我不希望他们被重新处理,所以这种行为是可以的。
但是,启动日志显示了一些奇怪的信息:
首先,它显示还原使用者客户端的创建。自动偏移复位无:

2019-07-19 10:20:17.120  INFO 82473 --- [           main] o.a.k.s.p.internals.StreamThread         : stream-thread [events-processor-9a8069c4-3fb6-4d76-a207-efbbadd52b8f-StreamThread-1] Creating restore consumer client
2019-07-19 10:20:17.123  INFO 82473 --- [           main] o.a.k.clients.consumer.ConsumerConfig    : ConsumerConfig values: 
    auto.commit.interval.ms = 5000
    auto.offset.reset = none

然后创建一个具有自动偏移重置功能的客户机。

2019-07-19 10:20:17.235  INFO 82473 --- [           main] o.a.k.s.p.internals.StreamThread         : stream-thread [events-processor-9a8069c4-3fb6-4d76-a207-efbbadd52b8f-StreamThread-1] Creating consumer client
2019-07-19 10:20:17.241  INFO 82473 --- [           main] o.a.k.clients.consumer.ConsumerConfig    : ConsumerConfig values: 
    auto.commit.interval.ms = 5000
    auto.offset.reset = earliest

启动日志的最后跟踪显示偏移量重置为0。每次重新启动应用程序时都会发生这种情况:

2019-07-19 10:20:31.577  INFO 82473 --- [-StreamThread-1] o.a.k.s.p.internals.StreamThread         : stream-thread [events-processor-9a8069c4-3fb6-4d76-a207-efbbadd52b8f-StreamThread-1] State transition from PARTITIONS_ASSIGNED to RUNNING
2019-07-19 10:20:31.578  INFO 82473 --- [-StreamThread-1] org.apache.kafka.streams.KafkaStreams    : stream-client [events-processor-9a8069c4-3fb6-4d76-a207-efbbadd52b8f] State transition from REBALANCING to RUNNING
2019-07-19 10:20:31.669  INFO 82473 --- [events-processor] o.a.k.c.consumer.internals.Fetcher       : [Consumer clientId=events-processor-9a8069c4-3fb6-4d76-a207-efbbadd52b8f-StreamThread-1-consumer, groupId=events-processor] Resetting offset for partition event-3 to offset 0.
2019-07-19 10:20:31.669  INFO 82473 --- [events-processor] o.a.k.c.consumer.internals.Fetcher       : [Consumer clientId=events-processor-9a8069c4-3fb6-4d76-a207-efbbadd52b8f-StreamThread-1-consumer, groupId=events-processor] Resetting offset for partition event-0 to offset 0.
2019-07-19 10:20:31.669  INFO 82473 --- [events-processor] o.a.k.c.consumer.internals.Fetcher       : [Consumer clientId=events-processor-9a8069c4-3fb6-4d76-a207-efbbadd52b8f-StreamThread-1-consumer, groupId=events-processor] Resetting offset for partition event-1 to offset 0.
2019-07-19 10:20:31.669  INFO 82473 --- [events-processor] o.a.k.c.consumer.internals.Fetcher       : [Consumer clientId=events-processor-9a8069c4-3fb6-4d76-a207-efbbadd52b8f-StreamThread-1-consumer, groupId=events-processor] Resetting offset for partition event-5 to offset 0.
2019-07-19 10:20:31.670  INFO 82473 --- [events-processor] o.a.k.c.consumer.internals.Fetcher       : [Consumer clientId=events-processor-9a8069c4-3fb6-4d76-a207-efbbadd52b8f-StreamThread-1-consumer, groupId=events-processor] Resetting offset for partition event-4 to offset 0.

为什么配置了两个消费者?
为什么第二个有 auto.offset.reset = earliest 当我没有显式地配置它并且Kafka默认值是最新的?
我想要默认的(auto.offset.reset=latest)行为,它看起来工作正常。然而,这与我在日志中看到的不矛盾吗?
更新:
我想把第三个问题改成这样:为什么日志显示分区在每次重新启动时都被重置为0,尽管如此,没有消息被重新传递到kstream?
更新2:
我已经简化了这个场景,这次使用了一个本地kafka流应用程序。这种现象与 Spring 云流的观测结果完全相同。然而,检查消费者组和分区我发现这是有意义的。
K流:

fun main() {

    val props = Properties()
    props[StreamsConfig.APPLICATION_ID_CONFIG] = "streams-wordcount"
    props[StreamsConfig.BOOTSTRAP_SERVERS_CONFIG] = "localhost:9092"
    props[StreamsConfig.CACHE_MAX_BYTES_BUFFERING_CONFIG] = 0
    props[StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG] = Serdes.String().javaClass.name
    props[StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG] = Serdes.String().javaClass.name

    val builder = StreamsBuilder()

    val source = builder.stream<String, String>("streams-plaintext-input")

    source.foreach { key, value -> println("$key $value") }

    val streams = KafkaStreams(builder.build(), props)
    val latch = CountDownLatch(1)

    // attach shutdown handler to catch control-c
    Runtime.getRuntime().addShutdownHook(object : Thread("streams-wordcount-shutdown-hook") {
        override fun run() {
            streams.close()
            latch.countDown()
        }
    })

    try {
        streams.start()
        latch.await()
    } catch (e: Throwable) {
        exitProcess(1)
    }

    exitProcess(0)
}

这就是我所看到的:
1) 如果主题为空,则启动将显示所有分区重置为偏移量0:

07:55:03.885 [streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-2 to offset 0.
07:55:03.886 [streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-3 to offset 0.
07:55:03.886 [streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-0 to offset 0.
07:55:03.886 [streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-1 to offset 0.
07:55:03.886 [streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-4 to offset 0.
07:55:03.886 [streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-3549a54e-49db-4490-bd9f-7156e972021a-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-5 to offset 0

2) 我在主题中放了一条消息并检查了消费者组,看到记录在分区4中:

TOPIC                   PARTITION  CURRENT-OFFSET  LOG-END-OFFSET  LAG             CONSUMER-ID                                                                                                         HOST            CLIENT-ID
streams-plaintext-input 0          -               0               -               streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer-905a307a-4c49-4d8b-ac2e-5525ba2e8a8e /127.0.0.1      streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer
streams-plaintext-input 5          -               0               -               streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer-905a307a-4c49-4d8b-ac2e-5525ba2e8a8e /127.0.0.1      streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer
streams-plaintext-input 1          -               0               -               streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer-905a307a-4c49-4d8b-ac2e-5525ba2e8a8e /127.0.0.1      streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer
streams-plaintext-input 2          -               0               -               streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer-905a307a-4c49-4d8b-ac2e-5525ba2e8a8e /127.0.0.1      streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer
streams-plaintext-input 3          -               0               -               streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer-905a307a-4c49-4d8b-ac2e-5525ba2e8a8e /127.0.0.1      streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer
streams-plaintext-input 4          1               1               0               streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer-905a307a-4c49-4d8b-ac2e-5525ba2e8a8e /127.0.0.1      streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer

3) 我重新启动应用程序。现在重置只影响空分区(0、1、2、3、5):

07:57:39.477 [streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-2 to offset 0.
07:57:39.478 [streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-3 to offset 0.
07:57:39.478 [streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-0 to offset 0.
07:57:39.479 [streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-1 to offset 0.
07:57:39.479 [streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-b1565eca-7d80-4550-97d2-e78ead62a840-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-5 to offset 0.

4) 我插入另一条消息,检查使用者组状态,同样的情况发生了:记录在分区2中,当重新启动应用程序时,它只重置空分区(0、1、3、5):

TOPIC                   PARTITION  CURRENT-OFFSET  LOG-END-OFFSET  LAG             CONSUMER-ID                                                                                                         HOST            CLIENT-ID
streams-plaintext-input 0          -               0               -               streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer-cb04e2bd-598f-455f-b913-1370b4144dd6 /127.0.0.1      streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer
streams-plaintext-input 5          -               0               -               streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer-cb04e2bd-598f-455f-b913-1370b4144dd6 /127.0.0.1      streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer
streams-plaintext-input 1          -               0               -               streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer-cb04e2bd-598f-455f-b913-1370b4144dd6 /127.0.0.1      streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer
streams-plaintext-input 2          1               1               0               streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer-cb04e2bd-598f-455f-b913-1370b4144dd6 /127.0.0.1      streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer
streams-plaintext-input 3          -               0               -               streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer-cb04e2bd-598f-455f-b913-1370b4144dd6 /127.0.0.1      streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer
streams-plaintext-input 4          1               1               0               streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer-cb04e2bd-598f-455f-b913-1370b4144dd6 /127.0.0.1      streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer
08:00:42.313 [streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-3 to offset 0.
08:00:42.314 [streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-0 to offset 0.
08:00:42.314 [streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-1 to offset 0.
08:00:42.314 [streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1] INFO org.apache.kafka.clients.consumer.internals.Fetcher - [Consumer clientId=streams-wordcount-addb08ed-62ce-47f9-a446-f2ee0592c53d-StreamThread-1-consumer, groupId=streams-wordcount] Resetting offset for partition streams-plaintext-input-5 to offset 0.
bttbmeg0

bttbmeg01#

为什么配置了两个消费者? Restore Consumer Client 是容错和状态管理的专用使用者。它负责从changelog主题恢复状态。它与应用程序使用者客户端分开显示。您可以在此处找到更多信息:https://docs.confluent.io/current/streams/monitoring.html#kafka-还原使用者客户端id
为什么第二个设置auto.offset.reset=earliest,而我没有显式配置它,并且kafka默认值是最新的?
你是对的, auto.offset.reset 默认值为 latest 在Kafka消费。但在SpringCloudStream中,消费者的默认值 startOffsetearliest . 因此它显示 earliest 第二消费者。也取决于 spring.cloud.stream.bindings.<channelName>.group 结合。如果显式设置,则 startOffset 设置为 earliest ,否则设置为 latest 为了 anonymous 消费者。
参考资料:Spring Cloud流Kafka消费物业
我想要默认的(auto.offset.reset=latest)行为,它看起来工作正常。然而,这与我在日志中看到的不矛盾吗?
万一 anonymous 使用者组,的默认值 startOffsetlatest .

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