SQSListener scales even if i manually set sync working

[VladislavKutsobin]

Type: Bug

Component: SQS

Describe the Bug
Hello!

Please, help me understand what i do wrong.
I apologize i can't share with you stack trace because the code under nda. I will try describe the problem:
I use 'spring-cloud-aws-starter-sqs' dependency, version 3.0.1. My configuration is auto (i don't define any beans - only credentials and region in application.properties).
Next, i use SqsListener like:
@SqsListener(value = "${sqs.balance.calculator}", maxConcurrentMessages = "1", maxMessagesPerPoll = "1")

So my main goal is correct calculation. Optimization is not important in my case. So i would my listener works sync.
I must do that because inside the method i adjust the same entity, and if i do it async - i have a lot of optimistic blocking exception.

But, the main reason why i write this issue is: Sometimes i catch errors: [Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect)]

And it mean that somewhere occurs autoscaling. But why, what i can do wrong?

Thanks!

[tomazfernandes]

Hi @VladislavKutsobin, sorry for the delay.

Are your instances autoscaling? If you have more than one server instance it will consume more than one message at a time.

Hard to say anything without more information. Perhaps message visibility is expiring?

It would be helpful if you could take a look at your logs. If there's a log in the end of message consumption, and one at the end, you should be able to see whether two messages are being consumed concurrently, or if there's anything else causing the issue.

Make sure to log some instance identifier and any other useful information.

Another option is - if you can create a minimal project that reproduces the issue I could take a look.

Thanks.