启动springboot服务器时如何绕过kafka代理失败？

Question

我在 spring-boot(2.1.7.RELEASE) 应用程序服务器中遇到问题，该服务器使用 spring-boot-Kafka('spring-Kafka' -'2.2.7.RELEASE') 集成库来访问我的 Kafka 主题。当我的 Kafka 代理关闭时，我的应用程序无法启动。这就是我得到的：2019-10-06 02:41:02.764  WARN -- [main           ] org.apache.kafka.clients.NetworkClient                       [] : [Consumer clientId=consumer-1, groupId=caas] Connection to node -1 could not be established. Broker may not be available.Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.2019-10-06 02:41:31.777 ERROR -- [main           ] org.springframework.boot.SpringApplication                   [] : Application run failedorg.springframework.context.ApplicationContextException: Failed to start bean 'org.springframework.kafka.config.internalKafkaListenerEndpointRegistry'; nested exception is org.apache.kafka.common.errors.TimeoutException: Timeout expired while fetching topic metadata    at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:185)    at org.springframework.context.support.DefaultLifecycleProcessor.access$200(DefaultLifecycleProcessor.java:53)    at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:360)    at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:158)    at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:122)    at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:893)    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh(ServletWebServerApplicationContext.java:162)    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:552)有没有办法绕过对 Kafka 代理的依赖？即使经纪人不可用/关闭，我也希望我的应用程序能够启动。一旦代理启动，应用程序服务器应该能够连接。

Answer 1

有一个容器属性missingTopicsFatal： https://docs.spring.io/spring-kafka/api/org/springframework/kafka/listener/ContainerProperties.html#isMissingTopicsFatal - 即使主题和/或经纪人不可用。

@Bean(name = "kafkaListenerContainerFactory")

public ConcurrentKafkaListenerContainerFactory<?, ?> kafkaListenerContainerFactory(

    ConsumerFactory<Object, Object> kafkaConsumerFactor,

    ConcurrentKafkaListenerContainerFactoryConfigurer configurer) {

  ConcurrentKafkaListenerContainerFactory<Object, Object> factory =

      new ConcurrentKafkaListenerContainerFactory<>();

  configurer.configure(factory, kafkaConsumerFactor);

  ContainerProperties containerProperties = factory.getContainerProperties();

  containerProperties.setMissingTopicsFatal(false);

  ...

  return factory;

}

Answer 2

这是新版本的spring的变化。

@Component

class ContainerFactoryConfigurer {

    ContainerFactoryConfigurer(ConcurrentKafkaListenerContainerFactory<?, ?> factory) {

        factory.getContainerProperties().setMissingTopicsFatal(false);

    }

}