Switch over Uni failures

[r00ta]

Hi!

I have an Uni that might throw some RuntimeExceptions. In some cases I'd like to retry, in some others I'd like only to transform the exception. Pseudocode:

try{
  asyncClient.getSecretValue();
  catch (ResourceNotFoundException e){
    throw new VaultException();
  }
  catch (RuntimeException e){
    retry();
  }
}

With mutiny I was trying something like

Uni<EventBridgeSecret> a = Uni.createFrom().future(asyncClient.getSecretValue(
                GetSecretValueRequest.builder()
                        .secretId(name)
                        .build()))
               .onFailure(ResourceNotFoundException.class).transform(e -> new VaultException("Secret '%s' not found in AWS Vault", e))
               .onFailure(e -> !(e instanceof ResourceNotFoundException)).retry().withJitter(DEFAULT_JITTER).withBackOff(DEFAULT_BACKOFF).atMost(MAX_RETRIES);

But of course the second onFailure is subscribed to the UniOnFailure and not to the original Uni. Do you have any tips for handle such pattern?

Thank you!

[cescoffier]

Shouldn't the onFailure predicate use VaultException instead of ResourceNotFoundException?

[r00ta]

Hi @cescoffier , asyncClient.getSecretValue throws exceptions that are library-specific, VaultException is defined in my project

[jponge]

Have you tried swapping the 2 onFailure handlers?

[r00ta]

Hi @jponge , I tried with

Uni<EventBridgeSecret> a = Uni.createFrom().future(asyncClient.getSecretValue(
                GetSecretValueRequest.builder()
                        .secretId(name)
                        .build()))
               .onFailure(e -> !(e instanceof ResourceNotFoundException)).retry().withJitter(DEFAULT_JITTER).withBackOff(DEFAULT_BACKOFF).atMost(MAX_RETRIES)
                .onFailure(ResourceNotFoundException.class).transform(e -> new VaultException("Secret '%s' not found in AWS Vault", e));

and it did the trick as you suggested. I guess I did not spot it because I was previously using until and I still get different behaviours, for example the snippet

    @Override
    public Uni<Void> test(){
        return Uni.createFrom().failure(new VaultException(""))
                .replaceWithVoid()
                .onFailure(e -> !(e instanceof VaultException)).retry().until(x -> {LOGGER.info("ARGUMENT!"); return false;})
                .onFailure(VaultException.class).retry().until(x -> {LOGGER.info("VAULT!"); return false;});
    }

prints

2022-01-18 09:23:29,553 INFO  [com.red.ser.bri.man.vau.AWSVaultServiceImpl] (main) ARGUMENT!
2022-01-18 09:23:29,554 INFO  [com.red.ser.bri.man.vau.AWSVaultServiceImpl] (main) VAULT!

when called. I would expect only VAULT to be printed, but it's not the case

[cescoffier]

Hum... Yes... Let me try.

[cescoffier]

Ok... it's a bug. The predicate is not used with until. I'm working on a fix.

CC @jponge

[jponge]

Resolved by @cescoffier in #817