Is there any way to stop runAlways = true migration from running always based on some variable ?

[rahulsant100]

I have a use case where I don't want to run the runAlways migration on the same application build number. There can be multiple reasons when the pod crash can happen or it was restarted. If a ChangeUnit is runAlways, I want it to be executed once only on the same application build number.

This application build number is injected in the application config once it is deployed.

[rahulsant100]

@dieppa

[dieppa]

Sorry @rahulsant100 , we discussed this and we thought we answered you.

However, I am not 100% clear what your use case is. My understanding is that you have a changeUnit with runAlways set to true and you want it to be executed in every deployment. Right now the changeUnit will be executed always per every node deployed(understanding node by any instance of the application or even when the application is restarted).

Nevertheless, you have some scenarios where you don't want this behaviour. Let's imagine you have two instances of the same application you are deploying. Currently, the changeUnit will be executed twice, one per instance, but you only want the changeUnit to be run once. Or if, having only one instance, the application is restarted, then you don't want the changeUnit to be run again.

Is my understanding correct, @rahulsant100 ?

CC: @osantana85 , @dhivesh @bercianor @davidfrigolet

[rahulsant100]

Yes @dieppa, We have a single instance of the application which is restarted. I don't want to run that changeUnit again. Let me explain you a bit more clearly, suppose we have an application having a config key "build number" = 24.05 having a changeUnit with runAlways set to true. Now, if I deploy that application, the changeUnit will be executed. But if I do a redeployment of the same application build that changeUnit shouldn't be executed.

Now, let's suppose I update my config key "build number" to 24.06. And then I do the deployment, the changeUnit should be executed.

So, the changeUnit should be executed once per new build deployment.

This use case is present in our system to avoid the latency caused by alwaysRun=true ChangeUnit on deployment of the same application build.

[dieppa]

I understand your point now. Unfortunately we don't have anything like that at the moment, however in the next big release, in which we are going to re-define the concept to provide what Mongock offers now, but mucho more, we will add that feature together with the concept of deployment.

In the meantime, I can think in some workarounds, not ideal, but it would work. For example, as part of your changeUnit, you could persist the app version, then that changeUnit would check if the app version(passed somehow as parameter) is different to what is persisted, in that case will run the code, other wise will pass.

Regards