[jira] [Commented] (IGNITE-14800) Add technical ability to differentiate between create and update in configuration

["Sergey Chugunov (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/IGNITE-14800?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17357115#comment-17357115 ] 

Sergey Chugunov commented on IGNITE-14800:
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[~ibessonov],

Patch looks good to me, it makes code more clear and straightforward. I approved your PR, please feel free to merge it to main branch.

Thank you!

> Add technical ability to differentiate between create and update in configuration
> ---------------------------------------------------------------------------------
>
>                 Key: IGNITE-14800
>                 URL: https://issues.apache.org/jira/browse/IGNITE-14800
>             Project: Ignite
>          Issue Type: Sub-task
>    Affects Versions: 3.0.0-alpha2
>            Reporter: Ivan Bessonov
>            Assignee: Ivan Bessonov
>            Priority: Major
>              Labels: ignite-3
>             Fix For: 3.0.0-alpha3
>
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> {{org.apache.ignite.configuration.internal.DynamicConfiguration#change}} method (and its variants in other classes) has a substantial disadvantage - it doesn't allow you to read current configuration in lambdas to decide a new value for some other configurations.
> Why is this the way it is? For simplicity of implementation, we immediately convert it to {{InnerNode}} and only then pass into configuration changer. This means that we will apply the same exact tree on every retry iteration.
> This is bad during concurrent resources creation, if you create 2 resources with the same name, then one of changes will be create and the other one is update. There is no way to tell what will happen until it is already happened. Such behavior is not convenient if you create SQL indexes or tables, for example, CREATE should not be silently converted to ALTER.
> Other reason why it's bad - it complicates concurrent array fields updates. Makes it nearly impossible.
> What should we do to fix it?
>  * CHANGE interfaces should extend VIEW interfaces. Lambda parameters should be available for read and provide configuration snapshot that's currently being updated;
>  * changing lambda should be applied on every retry. Only then we could guarantee that provided configuration snapshots are valid;
>  * consider using the same procedure for arbitrary configuration sources. This will save us some code and will be handy in https://issues.apache.org/jira/browse/IGNITE-14645 implementation.



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