对此的更新：我们有spring-retry依赖关系，但重试不起作用，因为默认情况下它只适用于 GET，我们的大多数调用都是 POST（但可以再次调用）。添加配置spring.cloud.loadbalancer.retry.retryOnAllOperations: true解决了这个问题，因此应该通过在第二次尝试时使用替代实例重试来避免大多数这些故障。
我们还添加了一个 RetryListener，它在某些连接异常时清除服务的负载均衡器缓存：
@Configuration
public class RetryConfig {
private static final Logger logger = LoggerFactory.getLogger(RetryConfig.class);
// Need to use bean factory here as can't autowire LoadBalancerCacheManager -
// - it's set to 'autowireCandidate = false' in LoadBalancerCacheAutoConfiguration
@Autowired
private BeanFactory beanFactory;
@Bean
public CacheClearingLoadBalancedRetryFactory cacheClearingLoadBalancedRetryFactory(ReactiveLoadBalancer.Factory<ServiceInstance> loadBalancerFactory) {
return new CacheClearingLoadBalancedRetryFactory(loadBalancerFactory);
}
// Extension of the default bean that defines a retry listener
public class CacheClearingLoadBalancedRetryFactory extends BlockingLoadBalancedRetryFactory {
public CacheClearingLoadBalancedRetryFactory(ReactiveLoadBalancer.Factory<ServiceInstance> loadBalancerFactory) {
super(loadBalancerFactory);
}
@Override
public RetryListener[] createRetryListeners(String service) {
RetryListener cacheClearingRetryListener = new RetryListener() {
@Override
public <T, E extends Throwable> boolean open(RetryContext context, RetryCallback<T, E> callback) { return true; }
@Override
public <T, E extends Throwable> void close(RetryContext context, RetryCallback<T, E> callback, Throwable throwable) {}
@Override
public <T, E extends Throwable> void onError(RetryContext context, RetryCallback<T, E> callback, Throwable throwable) {
logger.warn("Retry for service {} picked up exception: context {}, throwable class {}", service, context, throwable.getClass());
if (throwable instanceof ConnectTimeoutException || throwable instanceof NoRouteToHostException) {
try {
LoadBalancerCacheManager loadBalancerCacheManager = beanFactory.getBean(LoadBalancerCacheManager.class);
Cache loadBalancerCache = loadBalancerCacheManager.getCache(CachingServiceInstanceListSupplier.SERVICE_INSTANCE_CACHE_NAME);
if (loadBalancerCache != null) {
boolean result = loadBalancerCache.evictIfPresent(service);
logger.warn("Load Balancer Cache evictIfPresent result for service {} is {}", service, result);
}
} catch(Exception e) {
logger.error("Failed to clear load balancer cache", e);
}
}
}
};
return new RetryListener[] { cacheClearingRetryListener };
}
}
}
这种方法有什么问题吗？可以将这样的东西添加到内置功能中吗？