“Reactive Redis:Spring Boot Application Start Fails, If Redis is Unavailable”

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英文:

Reactive Redis:Spring Boot Application Start Fails, If Redis is Unavailable

问题

我们正在使用Reactive Redis来缓存Web客户端的响应。如果Redis服务器正常运行，应用程序会正常工作。但是如果我们停止Redis，应用程序启动会失败。预期行为是即使Redis连接失败，应用程序仍然应该继续启动。Spring是否处理连接异常？还是我们需要处理这种异常？

以下是我用于配置Redis的代码：

import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.ReactiveRedisConnection;
import org.springframework.data.redis.connection.ReactiveRedisConnectionFactory;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.ReactiveRedisTemplate;
import org.springframework.data.redis.serializer.RedisSerializationContext;

@Configuration
@ConditionalOnClass({ReactiveRedisTemplate.class, RedisConnectionFactory.class,
                     LettuceConnectionFactory.class, ReactiveRedisConnectionFactory.class})
public class RedisConfiguration {

    @Bean
    public ReactiveRedisConnectionFactory reactiveRedisConnectionFactory() {
        return new LettuceConnectionFactory();
    }

    @Bean
    public ReactiveRedisConnection reactiveRedisConnection(final ReactiveRedisConnectionFactory redisConnectionFactory) {
        return redisConnectionFactory.getReactiveConnection();
    }

    @Bean
    public ReactiveRedisTemplate<String, String> reactiveRedisTemplateString
            (ReactiveRedisConnectionFactory connectionFactory) {
        return new ReactiveRedisTemplate<>(connectionFactory, RedisSerializationContext.string());
    }
}

异常信息如下：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'reactiveRedisConnection' defined in class path resource 
org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to localhost:6379
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:655)
	...
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.redis.connection.ReactiveRedisConnection]: Factory method 'reactiveRedisConnection' threw exception; nested exception is org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to localhost:6379
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
	...
Caused by: org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to localhost:6379
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getNativeConnection(LettuceConnectionFactory.java:1227)
	...
Caused by: io.lettuce.core.RedisConnectionException: Unable to connect to localhost:6379
	at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:78)
	...
Caused by: io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: localhost/127.0.0.1:6379
Caused by: java.net.ConnectException: Connection refused
	...

希望这有助于解决您的问题。

英文:

We are using Reactive Redis to cache web-client response.If Redis server is up and running application works fine.But App start up is failing ,if we stop redis. Expected behavior is app should still go ahead and start even though redis connection fails.Does spring handles connection exception?or do we have to handle this kind of exceptions?

Here is the code I used to configure redis;

import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.ReactiveRedisConnection;
import org.springframework.data.redis.connection.ReactiveRedisConnectionFactory;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.ReactiveRedisTemplate;
import org.springframework.data.redis.serializer.RedisSerializationContext;
@Configuration
@ConditionalOnClass({ReactiveRedisTemplate.class, RedisConnectionFactory.class,
LettuceConnectionFactory.class, ReactiveRedisConnectionFactory.class})
public class RedisConfiguration {
@Bean
public ReactiveRedisConnectionFactory reactiveRedisConnectionFactory() {
return new LettuceConnectionFactory();
}
@Bean
public ReactiveRedisConnection reactiveRedisConnection(final ReactiveRedisConnectionFactory redisConnectionFactory) {
return redisConnectionFactory.getReactiveConnection();
}
@Bean
public ReactiveRedisTemplate&lt;String, String&gt; reactiveRedisTemplateString
(ReactiveRedisConnectionFactory connectionFactory) {
return new ReactiveRedisTemplate&lt;&gt;(connectionFactory, RedisSerializationContext.string());
}
}

Exception

org.springframework.beans.factory.BeanCreationException: Error creating bean with name &#39;reactiveRedisConnection&#39; defined in class path resource 
org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to localhost:6379
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:655)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:635)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:893)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:879)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551)
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:62)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
at com.demo.obapi.redis.Application.main(Application.:30)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.redis.connection.ReactiveRedisConnection]: Factory method &#39;reactiveRedisConnection&#39; threw exception; nested exception is org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to localhost:6379
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:650)
... 20 common frames omitted
Caused by: org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to localhost:6379
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getNativeConnection(LettuceConnectionFactory.java:1227)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getConnection(LettuceConnectionFactory.java:1206)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getSharedReactiveConnection(LettuceConnectionFactory.java:980)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getReactiveConnection(LettuceConnectionFactory.java:441)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getReactiveConnection(LettuceConnectionFactory.java:95)
at com.demo.example.redis.cache.config.RedisConfiguration.reactiveRedisConnection(RedisConfiguration.java:63)
at com.demo.example.redis.cache.config.RedisConfiguration$$EnhancerBySpringCGLIB$$63b514a4.CGLIB$reactiveRedisConnection$0(&lt;generated&gt;)
at com.demo.example.redis.cache.config.RedisConfiguration$$EnhancerBySpringCGLIB$$63b514a4$$FastClassBySpringCGLIB$$a05cf79e.invoke(&lt;generated&gt;)
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244)
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331)
at com.demo.obapi.redis.cache.config.RedisConfiguration$$EnhancerBySpringCGLIB$$63b514a4.reactiveRedisConnection(&lt;generated&gt;)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
... 21 common frames omitted
Caused by: io.lettuce.core.RedisConnectionException: Unable to connect to localhost:6379
at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:78)
at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:56)
at io.lettuce.core.AbstractRedisClient.getConnection(AbstractRedisClient.java:234)
at io.lettuce.core.RedisClient.connect(RedisClient.java:207)
at org.springframework.data.redis.connection.lettuce.StandaloneConnectionProvider.lambda$getConnection$1(StandaloneConnectionProvider.java:115)
at java.base/java.util.Optional.orElseGet(Optional.java:369)
at org.springframework.data.redis.connection.lettuce.StandaloneConnectionProvider.getConnection(StandaloneConnectionProvider.java:115)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getNativeConnection(LettuceConnectionFactory.java:1225)
... 36 common frames omitted
Caused by: io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: localhost/127.0.0.1:6379
Caused by: java.net.ConnectException: Connection refused
at java.base/sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at java.base/sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:779)
at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:330)
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:334)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:702)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:834)

答案1

得分: 0

Spring Boot自动处理Redis连接，我们不需要自己的自定义类。我从我的代码中删除了上面的类，现在我可以看到连接失败，但应用程序成功启动。

英文:

Spring boot automatically handles redis connection, we don't need our own custom class.Removed above class from my code, now I can see connection fails but app starts successfully.

huangapple
  • 本文由 发表于 2020年8月4日 10:06:41
  • 转载请务必保留本文链接：https://go.coder-hub.com/63239258.html
  • java
  • project-reactor
  • redis
  • spring
  • spring-webflux
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