[QUESTION] Mitigation around AWS RDS write forwarding in read only replicas

[ls-urs-keller]

Summary

We had some issues around AWS RDS with cross region replication and rw/ro replicas with write forwarding.
I believe it is a bug on the AWS side. But it would be good if it could be mitigated.

Analysis here: https://github.com/ls-urs-keller/r2dbc-test

Mitigation: don't issue "START TRANSACTION READ WRITE" but either just "BEGIN" or "START TRANSACTION" if the transaction is readonly=false.

Checklist

• I have searched the existing issues to make sure my question has not been asked before
• I have provided all the necessary information and context to help answer my question
• I have read the documentation and/or README for this project (if applicable)

[jchrys]

Thanks for providing the details that really helps. Let me check if we can implement this without affecting current behavior.

[ls-urs-keller]

Thanks for providing the details that really helps. Let me check if we can implement this without affecting current behavior.

I have a support call with AWS, they can't reproduce, before changing anything let me come back to you with the results of that call.

[jchrys]

Got it :D

[ls-urs-keller]

Got it :D

Sorry for the late reply.
So AWS support says it is a permission problem on our side. To use START TRANSACTION READ WRITE you will need more permissions than when using BEGIN or START TRANSACTION go figure.

I guess to make this work with AWD RDS and write forwarding you must not not issue START TRANSACTION READ WRITE.

[jchrys]

Thanks for update :D
I’ll check if we can adjust our implementation accordingly.