Spring @Retryable - how to log when it is invoked?

问题

I use compile 'org.springframework.retry:spring-retry:1.2.2.RELEASE'with Spring Boot 1.5.9.RELEASE.

Configured to retry my method and it works well:

@Retryable(value = { IOException.class }, maxAttempts = 5, backoff = @Backoff(delay = 500))
public void someMethod(){...}

How to output some specific message when retry occurs?

回答1:

You can register a RetryListener:

@Bean
public List<RetryListener> retryListeners() {
    Logger log = LoggerFactory.getLogger(getClass());

    return Collections.singletonList(new RetryListener() {

        @Override
        public <T, E extends Throwable> boolean open(RetryContext context, RetryCallback<T, E> callback) {
            // The 'context.name' attribute has not been set on the context yet. So we have to use reflection.
            Field labelField = ReflectionUtils.findField(callback.getClass(), "val$label");
            ReflectionUtils.makeAccessible(labelField);
            String label = (String) ReflectionUtils.getField(labelField, callback);
            log.trace("Starting retryable method {}", label);
            return true;
        }

        @Override
        public <T, E extends Throwable> void onError(RetryContext context, RetryCallback<T, E> callback, Throwable throwable) {
            log.warn("Retryable method {} threw {}th exception {}",
                    context.getAttribute("context.name"), context.getRetryCount(), throwable.toString());
        }

        @Override
        public <T, E extends Throwable> void close(RetryContext context, RetryCallback<T, E> callback, Throwable throwable) {
            log.trace("Finished retryable method {}", context.getAttribute("context.name"));
        }
    });

If you don't need to log from all 3 interception points, you can override RetryListenerSupport instead. For example:

@Bean
public List<RetryListener> retryListeners() {
    Logger log = LoggerFactory.getLogger(getClass());

    return Collections.singletonList(new RetryListenerSupport() {

        @Override
        public <T, E extends Throwable> void onError(
                RetryContext context, RetryCallback<T, E> callback, Throwable throwable) {
            log.warn("Retryable method {} threw {}th exception {}",
                    context.getAttribute("context.name"), 
                    context.getRetryCount(), throwable.toString());
        }
    });
}

回答2:

Looking through the code the org.springframework.retry.support.RetryTemplate performs the retry logic for retrying the operations. This template only logs simple things like:

o.s.retry.support.RetryTemplate          : Retry: count=0
o.s.retry.support.RetryTemplate          : Checking for rethrow: count=1
o.s.retry.support.RetryTemplate          : Retry: count=1
o.s.retry.support.RetryTemplate          : Checking for rethrow: count=2
o.s.retry.support.RetryTemplate          : Retry: count=2
o.s.retry.support.RetryTemplate          : Checking for rethrow: count=3
o.s.retry.support.RetryTemplate          : Retry failed last attempt: count=3

If you want to log the specific exception you could catch the exception log it and rethrow. Unfortunately as far as i can see there is no way to log custom messages within the framework.

Another method would be to shadow the actual interceptor responsible for the invocation of your method like RetryOperationsInterceptor, this is not advised however.

来源：https://stackoverflow.com/questions/49066706/spring-retryable-how-to-log-when-it-is-invoked

标签

Spring

spring-boot

Spring-Retry