support per-record observations in batch listeners

[igormq]

Don't know if i am doing the right approach here, but.

• support per-record observations in batch listeners
• document recordObservationsInBatch container property
• describe new option in the change history
• add integration test for per-record observations

Related to #3872 (comment)

[sobychacko]

@igormq Thank you for the PR. We will do a detailed review soon. But, please add your name as an author to the classes you modified. Also, make the modifications in the ref docs directly and then add a short sentence about it in the whats-new doc. The change history is only for previous versions. Thanks!

[artembilan]

Thank you for looking into this!
Not easy task to tackle.
Hope you'll find my review as reasonable.

[sobychacko]

@igormq Thank you for this PR. Implementing observability with batch listeners is not trivial, and I think you laid good foundations here. Providing this as an optional feature is very important, as we don't want to impose observability by default in all batch listeners. Please take a look at some of the feedback I provided, which largely echoes what @artembilan has already reviewed. As you make further changes, we will need to add docs and other related components, but getting the implementation right is the critical step right now. Thanks again!

[igormq]

@igormq Thank you for this PR. Implementing observability with batch listeners is not trivial, and I think you laid good foundations here. Providing this as an optional feature is very important, as we don't want to impose observability by default in all batch listeners. Please take a look at some of the feedback I provided, which largely echoes what @artembilan has already reviewed. As you make further changes, we will need to add docs and other related components, but getting the implementation right is the critical step right now. Thanks again!

Hey @sobychacko and @artembilan thank you so much for all the feedback, really appreciate! I think that i addressed all of them. Let me know if I am missing something :)

[sobychacko]

@igormq Code changes look good. Now, we need to add reference docs with instructions on enabling observability in batch mode, maybe some examples etc. Then we need to mention this new feature in the whats-new doc.

[igormq]

Now, we need to add reference docs with instructions on enabling observability in batch mode, maybe some examples et

done that, and also fixed the check style issues

[artembilan]

I'm not sure if you broke something with your change, but we have to revise that an observation is really created for the whole batch around that listener method call.
If that was not supported at all, then it is OK.