Am I still able to intercept exceptions on retry to emit client side metrics?

[kevinrobayna]

Describe the issue

In v1 I was able to add a lambda to intercept exceptions in client and emit metrics if desired, I'm struggling to do the same with v2.

import com.amazonaws.retry.PredefinedRetryPolicies;
import com.amazonaws.retry.RetryPolicy;

  private RetryPolicy buildRetryPolicy() {
    return new RetryPolicy(
        (originalRequest, exception, retriesAttempted) -> {
          LOGGER.info("AWS failed with exception {}", exception.getClass());
          if (exception instanceof ProvisionedThroughputExceededException) {
            metrics.getCounter(PROVIDER_EXCEPTION,Map.of("exception", "ProvisionedThroughputExceededException")).inc();
          }
          return PredefinedRetryPolicies.DEFAULT_RETRY_CONDITION.shouldRetry(
              originalRequest, exception, retriesAttempted);
        },
        PredefinedRetryPolicies.DEFAULT_BACKOFF_STRATEGY,
        PredefinedRetryPolicies.DEFAULT_MAX_ERROR_RETRY,
        false);
  }

Your Environment

• AWS Java SDK version used: '2.15.26'
• JDK version used: 11
• Operating System and version: N/A

[debora-ito]

RetryCondition is what you're looking for, here's a super quick code example:

RetryPolicy policy =  RetryPolicy.builder()
            .retryCondition(
                retryPolicyContext -> {
                    if (retryPolicyContext.exception() instanceof ProvisionedThroughputExceededException)
                         // add metrics
                    return false;
                })
            .build();

[kevinrobayna]

That might be exactly what i need! Thanks! I'll try it out.

[kevinrobayna]

@debora-ito but this return false; that it won't be retried. I don't want to change the default way I just want to intercept the method to log the exceptions.

          return PredefinedRetryPolicies.DEFAULT_RETRY_CONDITION.shouldRetry(
              originalRequest, exception, retriesAttempted);

[debora-ito]

You are correct, I just wanted to show a way to use the RetryCondition, you'd need to add your logic.

[debora-ito]

return RetryCondition.defaultRetryCondition().shouldRetry(RetryPolicyContext.builder().build());

Let us know if this would help.

[kevinrobayna]

Thanks! that worked. For anyone who reads this in the future.

            RetryPolicy.defaultRetryPolicy().toBuilder()
                .retryCondition(
                    retryPolicyContext -> {
                      LOGGER.info("AWS failed with exception {}", retryPolicyContext.getClass());
                      // send metrics
                      return RetryCondition.defaultRetryCondition().shouldRetry(retryPolicyContext);
                    })
                .build())