🧵 Struggling with custom exponential retries in your Spring Boot Kafka application? Here’s a quick guide to get it working!
1/7 Dependency Setup:
Ensure you have the necessary dependencies in your pom.xml or build.gradle. You need spring-kafka and spring-retry.
<span><dependency></span><span><groupId></span>org.springframework.kafka<span></groupId></span><span><artifactId></span>spring-kafka<span></artifactId></span><span></dependency></span><span><dependency></span><span><groupId></span>org.springframework.retry<span></groupId></span><span><artifactId></span>spring-retry<span></artifactId></span><span></dependency></span><span><dependency></span> <span><groupId></span>org.springframework.kafka<span></groupId></span> <span><artifactId></span>spring-kafka<span></artifactId></span> <span></dependency></span> <span><dependency></span> <span><groupId></span>org.springframework.retry<span></groupId></span> <span><artifactId></span>spring-retry<span></artifactId></span> <span></dependency></span><dependency> <groupId>org.springframework.kafka</groupId> <artifactId>spring-kafka</artifactId> </dependency> <dependency> <groupId>org.springframework.retry</groupId> <artifactId>spring-retry</artifactId> </dependency>
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2/7 ️ Configuration:
Create a Kafka configuration class to set up retry policies. Use RetryTemplate for exponential backoff.
<span>@Configuration</span><span>public</span> <span>class</span> <span>KafkaConfig</span> <span>{</span><span>@Bean</span><span>public</span> <span>RetryTemplate</span> <span>retryTemplate</span><span>()</span> <span>{</span><span>RetryTemplate</span> <span>retryTemplate</span> <span>=</span> <span>new</span> <span>RetryTemplate</span><span>();</span><span>FixedBackOffPolicy</span> <span>backOffPolicy</span> <span>=</span> <span>new</span> <span>FixedBackOffPolicy</span><span>();</span><span>backOffPolicy</span><span>.</span><span>setBackOffPeriod</span><span>(</span><span>1000</span><span>);</span> <span>// initial interval</span><span>retryTemplate</span><span>.</span><span>setBackOffPolicy</span><span>(</span><span>backOffPolicy</span><span>);</span><span>retryTemplate</span><span>.</span><span>setRetryPolicy</span><span>(</span><span>new</span> <span>SimpleRetryPolicy</span><span>(</span><span>3</span><span>));</span> <span>// max attempts</span><span>return</span> <span>retryTemplate</span><span>;</span><span>}</span><span>}</span><span>@Configuration</span> <span>public</span> <span>class</span> <span>KafkaConfig</span> <span>{</span> <span>@Bean</span> <span>public</span> <span>RetryTemplate</span> <span>retryTemplate</span><span>()</span> <span>{</span> <span>RetryTemplate</span> <span>retryTemplate</span> <span>=</span> <span>new</span> <span>RetryTemplate</span><span>();</span> <span>FixedBackOffPolicy</span> <span>backOffPolicy</span> <span>=</span> <span>new</span> <span>FixedBackOffPolicy</span><span>();</span> <span>backOffPolicy</span><span>.</span><span>setBackOffPeriod</span><span>(</span><span>1000</span><span>);</span> <span>// initial interval</span> <span>retryTemplate</span><span>.</span><span>setBackOffPolicy</span><span>(</span><span>backOffPolicy</span><span>);</span> <span>retryTemplate</span><span>.</span><span>setRetryPolicy</span><span>(</span><span>new</span> <span>SimpleRetryPolicy</span><span>(</span><span>3</span><span>));</span> <span>// max attempts</span> <span>return</span> <span>retryTemplate</span><span>;</span> <span>}</span> <span>}</span>@Configuration public class KafkaConfig { @Bean public RetryTemplate retryTemplate() { RetryTemplate retryTemplate = new RetryTemplate(); FixedBackOffPolicy backOffPolicy = new FixedBackOffPolicy(); backOffPolicy.setBackOffPeriod(1000); // initial interval retryTemplate.setBackOffPolicy(backOffPolicy); retryTemplate.setRetryPolicy(new SimpleRetryPolicy(3)); // max attempts return retryTemplate; } }
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3/7 Exponential Backoff Policy:
For exponential backoff, use ExponentialBackOffPolicy.
<span>@Bean</span><span>public</span> <span>RetryTemplate</span> <span>retryTemplate</span><span>()</span> <span>{</span><span>RetryTemplate</span> <span>retryTemplate</span> <span>=</span> <span>new</span> <span>RetryTemplate</span><span>();</span><span>ExponentialBackOffPolicy</span> <span>backOffPolicy</span> <span>=</span> <span>new</span> <span>ExponentialBackOffPolicy</span><span>();</span><span>backOffPolicy</span><span>.</span><span>setInitialInterval</span><span>(</span><span>1000</span><span>);</span><span>backOffPolicy</span><span>.</span><span>setMaxInterval</span><span>(</span><span>10000</span><span>);</span><span>backOffPolicy</span><span>.</span><span>setMultiplier</span><span>(</span><span>2</span><span>);</span><span>retryTemplate</span><span>.</span><span>setBackOffPolicy</span><span>(</span><span>backOffPolicy</span><span>);</span><span>retryTemplate</span><span>.</span><span>setRetryPolicy</span><span>(</span><span>new</span> <span>SimpleRetryPolicy</span><span>(</span><span>3</span><span>));</span><span>return</span> <span>retryTemplate</span><span>;</span><span>}</span><span>@Bean</span> <span>public</span> <span>RetryTemplate</span> <span>retryTemplate</span><span>()</span> <span>{</span> <span>RetryTemplate</span> <span>retryTemplate</span> <span>=</span> <span>new</span> <span>RetryTemplate</span><span>();</span> <span>ExponentialBackOffPolicy</span> <span>backOffPolicy</span> <span>=</span> <span>new</span> <span>ExponentialBackOffPolicy</span><span>();</span> <span>backOffPolicy</span><span>.</span><span>setInitialInterval</span><span>(</span><span>1000</span><span>);</span> <span>backOffPolicy</span><span>.</span><span>setMaxInterval</span><span>(</span><span>10000</span><span>);</span> <span>backOffPolicy</span><span>.</span><span>setMultiplier</span><span>(</span><span>2</span><span>);</span> <span>retryTemplate</span><span>.</span><span>setBackOffPolicy</span><span>(</span><span>backOffPolicy</span><span>);</span> <span>retryTemplate</span><span>.</span><span>setRetryPolicy</span><span>(</span><span>new</span> <span>SimpleRetryPolicy</span><span>(</span><span>3</span><span>));</span> <span>return</span> <span>retryTemplate</span><span>;</span> <span>}</span>@Bean public RetryTemplate retryTemplate() { RetryTemplate retryTemplate = new RetryTemplate(); ExponentialBackOffPolicy backOffPolicy = new ExponentialBackOffPolicy(); backOffPolicy.setInitialInterval(1000); backOffPolicy.setMaxInterval(10000); backOffPolicy.setMultiplier(2); retryTemplate.setBackOffPolicy(backOffPolicy); retryTemplate.setRetryPolicy(new SimpleRetryPolicy(3)); return retryTemplate; }
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4/7 Consumer Factory:
Integrate the RetryTemplate with your Kafka consumer factory.
<span>@Bean</span><span>public</span> <span>ConcurrentKafkaListenerContainerFactory</span><span><</span><span>String</span><span>,</span> <span>String</span><span>></span> <span>kafkaListenerContainerFactory</span><span>()</span> <span>{</span><span>ConcurrentKafkaListenerContainerFactory</span><span><</span><span>String</span><span>,</span> <span>String</span><span>></span> <span>factory</span> <span>=</span><span>new</span> <span>ConcurrentKafkaListenerContainerFactory</span><span><>();</span><span>factory</span><span>.</span><span>setConsumerFactory</span><span>(</span><span>consumerFactory</span><span>());</span><span>factory</span><span>.</span><span>setRetryTemplate</span><span>(</span><span>retryTemplate</span><span>());</span><span>return</span> <span>factory</span><span>;</span><span>}</span><span>@Bean</span> <span>public</span> <span>ConcurrentKafkaListenerContainerFactory</span><span><</span><span>String</span><span>,</span> <span>String</span><span>></span> <span>kafkaListenerContainerFactory</span><span>()</span> <span>{</span> <span>ConcurrentKafkaListenerContainerFactory</span><span><</span><span>String</span><span>,</span> <span>String</span><span>></span> <span>factory</span> <span>=</span> <span>new</span> <span>ConcurrentKafkaListenerContainerFactory</span><span><>();</span> <span>factory</span><span>.</span><span>setConsumerFactory</span><span>(</span><span>consumerFactory</span><span>());</span> <span>factory</span><span>.</span><span>setRetryTemplate</span><span>(</span><span>retryTemplate</span><span>());</span> <span>return</span> <span>factory</span><span>;</span> <span>}</span>@Bean public ConcurrentKafkaListenerContainerFactory<String, String> kafkaListenerContainerFactory() { ConcurrentKafkaListenerContainerFactory<String, String> factory = new ConcurrentKafkaListenerContainerFactory<>(); factory.setConsumerFactory(consumerFactory()); factory.setRetryTemplate(retryTemplate()); return factory; }
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5/7 ️ Consumer Factory Method:
Define the consumer factory method as well.
<span>@Bean</span><span>public</span> <span>ConsumerFactory</span><span><</span><span>String</span><span>,</span> <span>String</span><span>></span> <span>consumerFactory</span><span>()</span> <span>{</span><span>Map</span><span><</span><span>String</span><span>,</span> <span>Object</span><span>></span> <span>props</span> <span>=</span> <span>new</span> <span>HashMap</span><span><>();</span><span>props</span><span>.</span><span>put</span><span>(</span><span>ConsumerConfig</span><span>.</span><span>BOOTSTRAP_SERVERS_CONFIG</span><span>,</span> <span>"localhost:9092"</span><span>);</span><span>props</span><span>.</span><span>put</span><span>(</span><span>ConsumerConfig</span><span>.</span><span>GROUP_ID_CONFIG</span><span>,</span> <span>"group_id"</span><span>);</span><span>props</span><span>.</span><span>put</span><span>(</span><span>ConsumerConfig</span><span>.</span><span>KEY_DESERIALIZER_CLASS_CONFIG</span><span>,</span> <span>StringDeserializer</span><span>.</span><span>class</span><span>);</span><span>props</span><span>.</span><span>put</span><span>(</span><span>ConsumerConfig</span><span>.</span><span>VALUE_DESERIALIZER_CLASS_CONFIG</span><span>,</span> <span>StringDeserializer</span><span>.</span><span>class</span><span>);</span><span>return</span> <span>new</span> <span>DefaultKafkaConsumerFactory</span><span><>(</span><span>props</span><span>);</span><span>}</span><span>@Bean</span> <span>public</span> <span>ConsumerFactory</span><span><</span><span>String</span><span>,</span> <span>String</span><span>></span> <span>consumerFactory</span><span>()</span> <span>{</span> <span>Map</span><span><</span><span>String</span><span>,</span> <span>Object</span><span>></span> <span>props</span> <span>=</span> <span>new</span> <span>HashMap</span><span><>();</span> <span>props</span><span>.</span><span>put</span><span>(</span><span>ConsumerConfig</span><span>.</span><span>BOOTSTRAP_SERVERS_CONFIG</span><span>,</span> <span>"localhost:9092"</span><span>);</span> <span>props</span><span>.</span><span>put</span><span>(</span><span>ConsumerConfig</span><span>.</span><span>GROUP_ID_CONFIG</span><span>,</span> <span>"group_id"</span><span>);</span> <span>props</span><span>.</span><span>put</span><span>(</span><span>ConsumerConfig</span><span>.</span><span>KEY_DESERIALIZER_CLASS_CONFIG</span><span>,</span> <span>StringDeserializer</span><span>.</span><span>class</span><span>);</span> <span>props</span><span>.</span><span>put</span><span>(</span><span>ConsumerConfig</span><span>.</span><span>VALUE_DESERIALIZER_CLASS_CONFIG</span><span>,</span> <span>StringDeserializer</span><span>.</span><span>class</span><span>);</span> <span>return</span> <span>new</span> <span>DefaultKafkaConsumerFactory</span><span><>(</span><span>props</span><span>);</span> <span>}</span>@Bean public ConsumerFactory<String, String> consumerFactory() { Map<String, Object> props = new HashMap<>(); props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092"); props.put(ConsumerConfig.GROUP_ID_CONFIG, "group_id"); props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class); props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class); return new DefaultKafkaConsumerFactory<>(props); }
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6/7 Listener:
Ensure your listener is configured properly to handle retries.
<span>@KafkaListener</span><span>(</span><span>topics</span> <span>=</span> <span>"topic_name"</span><span>,</span> <span>groupId</span> <span>=</span> <span>"group_id"</span><span>)</span><span>public</span> <span>void</span> <span>listen</span><span>(</span><span>String</span> <span>message</span><span>)</span> <span>{</span><span>// Your message handling logic</span><span>System</span><span>.</span><span>out</span><span>.</span><span>println</span><span>(</span><span>"Received message: "</span> <span>+</span> <span>message</span><span>);</span><span>// Simulate error for retry</span><span>if</span> <span>(</span><span>message</span><span>.</span><span>equals</span><span>(</span><span>"retry"</span><span>))</span> <span>{</span><span>throw</span> <span>new</span> <span>RuntimeException</span><span>(</span><span>"Simulated error"</span><span>);</span><span>}</span><span>}</span><span>@KafkaListener</span><span>(</span><span>topics</span> <span>=</span> <span>"topic_name"</span><span>,</span> <span>groupId</span> <span>=</span> <span>"group_id"</span><span>)</span> <span>public</span> <span>void</span> <span>listen</span><span>(</span><span>String</span> <span>message</span><span>)</span> <span>{</span> <span>// Your message handling logic</span> <span>System</span><span>.</span><span>out</span><span>.</span><span>println</span><span>(</span><span>"Received message: "</span> <span>+</span> <span>message</span><span>);</span> <span>// Simulate error for retry</span> <span>if</span> <span>(</span><span>message</span><span>.</span><span>equals</span><span>(</span><span>"retry"</span><span>))</span> <span>{</span> <span>throw</span> <span>new</span> <span>RuntimeException</span><span>(</span><span>"Simulated error"</span><span>);</span> <span>}</span> <span>}</span>@KafkaListener(topics = "topic_name", groupId = "group_id") public void listen(String message) { // Your message handling logic System.out.println("Received message: " + message); // Simulate error for retry if (message.equals("retry")) { throw new RuntimeException("Simulated error"); } }
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7/7 Wrap Up:
With these configurations, your Spring Boot Kafka application should now properly handle custom exponential retries.
原文链接：How to Implement Custom Exponential Retry in Spring Boot with Kafka
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