Alibaba Cloud SDK：重試策略配置

配置方式

可以在非同步用戶端中通過RetryPolicy配置重試策略。RetryPolicy支援設定退避策略、重試條件以及最大重試次數，範例程式碼如下：

AsyncClient client = AsyncClient.builder()
        .credentialsProvider(provider)
        .overrideConfiguration(
                darabonba.core.client.ClientOverrideConfiguration.create()
                        // 設定重試策略
                        .setRetryPolicy(darabonba.core.policy.retry.RetryPolicy.builder()
                                .backoffStrategy(darabonba.core.policy.retry.backoff.BackoffStrategy.defaultStrategy())
                                .retryCondition(darabonba.core.policy.retry.conditions.RetryCondition.defaultRetryCondition())
                                .numRetries(3)
                                .build()
                        )
        )
        .build();

參數說明

BackoffStrategy

退避策略，支援配置基礎延遲（baseDelay）和最大重試延遲時間（maxBackoffTime）。您可以通過以下方式自訂BackoffStrategy：

darabonba.core.policy.retry.backoff.FullJitterBackoffStrategy.builder()
        .baseDelay(java.time.Duration.ofMillis(100))
        .maxBackoffTime(java.time.Duration.ofMillis(20000))
        .build();

• baseDelay：基礎延時，重試延時時間將根據baseDelay以指數級增長。預設值為100毫秒。

• maxBackoffTime：最大重試延遲時間。當重試延時時間超過maxBackoffTime的設定值時，後續的重試延遲時間將固定為maxBackoffTime的值。預設值為20000毫秒。

RetryCondition

重試觸發條件，支援兩種類型：StatusCodeCondition和ExceptionsCondition。預設情況下，StatusCodeCondition包含408、429、500、502、503和504；ExceptionsCondition包含AliyunException和IOException。當StatusCodeCondition和ExceptionsCondition中的任意一個條件得到滿足時，系統將觸發重試。

您可以通過以下方式自訂重試觸發條件：

• 所有條件都滿足時觸發重試。

  darabonba.core.policy.retry.conditions.AndRetryCondition.create(RetryCondition... conditions)

  配置樣本：

  java.util.Set<Integer> statusCodeConditions = new java.util.HashSet<>();
  statusCodeConditions.add(408);
  statusCodeConditions.add(429);
  statusCodeConditions.add(500);
  statusCodeConditions.add(502);
  statusCodeConditions.add(503);
  statusCodeConditions.add(504);
  darabonba.core.policy.retry.conditions.StatusCodeCondition statusCodeCondition = darabonba.core.policy.retry.conditions.StatusCodeCondition.create(statusCodeConditions);
  java.util.Set<Class<? extends Exception>> exceptionsConditions = new java.util.HashSet<>();
  exceptionsConditions.add(com.aliyun.core.exception.AliyunException.class);
  exceptionsConditions.add(java.io.IOException.class);
  darabonba.core.policy.retry.conditions.ExceptionsCondition exceptionsCondition = darabonba.core.policy.retry.conditions.ExceptionsCondition.create(exceptionsConditions);
  darabonba.core.policy.retry.conditions.AndRetryCondition andRetryCondition = darabonba.core.policy.retry.conditions.AndRetryCondition.create(statusCodeCondition, exceptionsCondition);

• 任意一個條件滿足時觸發重試。

  darabonba.core.policy.retry.conditions.OrRetryCondition.create(RetryCondition... conditions)

  配置樣本：

  java.util.Set<Integer> statusCodeConditions = new java.util.HashSet<>();
  statusCodeConditions.add(408);
  statusCodeConditions.add(429);
  statusCodeConditions.add(500);
  statusCodeConditions.add(502);
  statusCodeConditions.add(503);
  statusCodeConditions.add(504);
  darabonba.core.policy.retry.conditions.StatusCodeCondition statusCodeCondition = darabonba.core.policy.retry.conditions.StatusCodeCondition.create(statusCodeConditions);
  java.util.Set<Class<? extends Exception>> exceptionsConditions = java.util.new HashSet<>();
  exceptionsConditions.add(com.aliyun.core.exception.AliyunException.class);
  exceptionsConditions.add(java.io.IOException.class);
  darabonba.core.policy.retry.conditions.ExceptionsCondition exceptionsCondition = darabonba.core.policy.retry.conditions.ExceptionsCondition.create(exceptionsConditions);
  darabonba.core.policy.retry.conditions.OrRetryCondition orRetryCondition = darabonba.core.policy.retry.conditions.OrRetryCondition.create(statusCodeCondition, exceptionsCondition);

numRetries

最大重試次數，預設值為3次。