启动springboot服务器时如何绕过kafka代理失败？

Question

我在使用 spring-boot-Kafka('spring-Kafka' -'2.2.7.RELEASE') 集成库访问我的 Kafka 的 spring-boot(2.1.7.RELEASE) 应用服务器中遇到问题话题。

当我的 Kafka 代理关闭时，我的应用程序无法启动。

这是我得到的：

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 failed

org.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)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:743)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:390)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:312)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1214)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1203)
    at com.zinka.fmsclients.FmsClientsApplication.main(FmsClientsApplication.java:14)
Caused by: org.apache.kafka.common.errors.TimeoutException: Timeout expired while fetching topic metadata

有没有办法绕过对 Kafka 代理的这种依赖？即使代理不可用/关闭，我也希望我的应用程序启动。代理启动后，应用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/或代理不可用，也允许应用程序启动。

@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spring的变化。

@Component
class ContainerFactoryConfigurer {

    ContainerFactoryConfigurer(ConcurrentKafkaListenerContainerFactory<?, ?> factory) {
        factory.getContainerProperties().setMissingTopicsFatal(false);
    }

}