Add support for AWS SQS

[arvidvillen]

Add support for AWS SQS: https://aws.amazon.com/sqs/

[tcerda95]

@cescoffier

I would love to collaborate with this implementation but I have a few theoretical doubts when it comes to backpressure and implementing the incoming connector.

First a high level overview of how SQS works. SQS offers a long polling mechanism (max 20 secs), can return up to a maximum of 10 messages per poll/batch and AWS offers an async SDK. So a very simple implementation for a PublisherBuilder I came up with is to poll indefefinitely and create a multi with each of the items per batch. Note that the async SQS client from the SDK returns a completion stage:

    public PublisherBuilder<? extends Message<?>> getSource() {
        Multi<Message<?>> publisher = Uni.createFrom()
            .completionStage(() -> sqsClient.receiveMessage(m -> m.queueUrl(url)))
            .repeat().indefinitely()
            .invoke(() -> System.out.println("Log SQS invocation"))
            .onItem().transformToIterable(ReceiveMessageResponse::messages)
            .onItem().transform(Message::of);

        return ReactiveStreams.fromPublisher(publisher);
    }

However, given that this implementation would poll indefinitely, would not this defeat the purpose of backpressure? Or will this only poll as long as downstream requests for more items?

Finally, thank you very much for your time.

[cescoffier]

I don't now SQS, but Mutiny will only retry when there is request. So, I believe the back pressure will be managed.

[MihaiBogdanEugen]

@tcerdaITBA I'd like to contribute to this as well. Have you made any progress on your side?

[soulseekeer24]

hello, anyone still interested on working on this?

[damiankaplon]

1. Is there any way for now to use smallrye-reactive-messaging with SQS? As far as i know it does not support amazon SQS for now. Am i right?
2. Is it possible to wrap SQS Client using JMS so i can integrate smallrye-reactive-messaging via JMS Connector?

[MihaiBogdanEugen]

1. You are right.

2. No.

[soulseekeer24]

anyone interested on working on adding SQS support ?XD

[adampoplawski]

Hello
Is there a change for this support? Maybe I can contribute somehow?

[cescoffier]

Sure, a contribution would be more than welcome.

[soulseekeer24]

i would like to help

[adampoplawski]

@tcerdaITBA are you still interested? It seems you did some work towards and now it seems there are ppl willing to support.

[holomekc]

Hi I started with an implementation:
https://github.com/holomekc/smallrye-reactive-messaging/commits/feature/AWS

I think I have no issues with the actual implementation. But there are some concepts which confuses me a little bit. So maybe you can help me to bring it into the right direction. But first the progress.

Progress:
Moved to the pr: #2402

[holomekc]

Questions:

1. Project structure
   I created an AWS module and a nested SQS module. Should I flatten the structure? I like the nested approach.
   What do you think

2. OpenTelemetry
   TracingUtils starts and ends the trace immediately. Does not that violate the OpenTelemetry documentation?:

   • Call shouldStart(Context, Object) and do not proceed if it returns false.
   • Call start(Context, Object) at the beginning of a request.
   • Call end(Context, Object, Object, Throwable) at the end of a request.

   In SQS when I send a message I get the messageId only in the response of the SDK lib. I cannot add this information
   to the span. Why isn't AsyncOperationEndStrategy
   used? For batching it is different. There I need to generate the ids before sending. But from an implementation perspective it
   would be easier to do that after the response as well.

3. Configuration
   For CreateQueue I want to provide the option to define attributes (Map<String, String) and tags (Map<String, String>).
   In case of sending messages I could use the metadata to provide this information. But this does not work for the
   incoming channel. The only way I found is to use the connector configuration. But Maps or Lists are not really supported.
   I need to parse from String manually (key1:value1,key2:value2 or value1,value2). This is something I cannot do inside of
   the message streams over and over again. It is a bit strange, because in microprofile config you could define maps.
   Quarkus also does this all the time.

   In general I think it depends on the use-case. I think for creation it is fine, because you most likely
   do not create that many queues. But what is the proper way to achieve something like this. I saw that sometimes beans
   are used to provide configuration. This is a bit strange to me

4. Graceful Shutdown
   I started with a terminate method and @BeforeDestroy. I saw that in the other implementations. But this is not really
   graceful. I cannot simply destroy the SDK client and the channels. I need to count some things. E.g. in case 10 messages are
   received I need to wait for the processing and I need to wait for the deletion/confirmation. I did this already in the past in
   a Quarkus lib. There the approach was more clear to me. Am I allowed to block the terminate method? It could take some
   time until the processing is done

Thank you for some help.

[adampoplawski]

@cescoffier can we get support with code review? It seems more people want to contribute.

[cescoffier]

Sure, @ozangunalp abd I would be happy to review the code

[adampoplawski]

Hello @cescoffier @ozangunalp . Sorry to ping again but maybe review was forgotten by accident :)

[cescoffier]

@adampoplawski where is the PR?

[adampoplawski]

Hello @cescoffier
There is branch plus questions from @holomekc how to proceed, sorry for miss information.
https://github.com/holomekc/smallrye-reactive-messaging/commits/feature/AWS

[holomekc]

I did not create a pr yet, because I did not write tests etc. yet. As @adampoplawski mentioned I wrote some questions. I needed to chill a little bit. I was working to much. I will try to finish what I started asap. I have some freetime soon-ish

[ozangunalp]

Thanks for this.
There is now a connector contribution guide if it may help you: https://smallrye.io/smallrye-reactive-messaging/4.11.0/concepts/contributing-connectors/

[holomekc]

I created the pr. It is not done yet, but maybe review, help etc. is easier to achieve:
#2402

[spc16670]

Are we planning to merge it anytime soon? Eagerly awaiting this....

[holomekc]

Nope. Feel free to help. There is still much to do.

[adampoplawski]

@cescoffier @ozangunalp There is new PR.