PIP-199: Create a robust and inline Client Feature Matrix page

[momo-jun]

Motivation

As the outcome of PIP-108, the Client Feature Matrix has addressed the initial user request for technology evaluation and selection. It has been linked on Pulsar doc site, providing an overview of feature supportability on language-specific clients.

However, it has the following limitations to continually serving the purpose over time:

1. Visibility: Not prominent for users/maintainers to notice.
2. Process control: No required review/approval or version control.
3. Accuracy: A bit out-of-dated with limited chances to get it updated (possibly caused by 1&2).

Goal

As an extension/enhancement to PIP-108, this proposal aims to make the existing client feature matrix more robust and prominent to address the above pain points and better serve the adoption purpose.

Implementation

Note: Instead of showing a full version to duplicate the existing feature matrix, this PIP aims to build a compact version with key features listed to serve the adoption purpose better.

1. Deliver a more robust Client Feature Matrix and required documentation through a thorough review and update.
   ----@RobertIndie and @shibd will be working on adding the information for missing features and supportability in language-specific clients.
2. Work out a compact feature list that makes more sense for adoption from a user perspective. ---- @ericsyh @liudezhi2098 reviewed the feature list.
3. Build the compact matrix on a web page to provide a better reading experience. Reference. ---- @urfreespace has researched it.

[tisonkun]

Thanks for starting this discussion. I'd like to mention my previous attempt in this direction https://github.com/apache/pulsar-site/issues/146.

I will take a closer look at this proposal in this week. Generally, I'd prefer inline the current feature matrix into each client's document entries instead of displaying the big feature matrix map in another approach - it consumes substantial developer efforts while it may not provide too much value.

[momo-jun]

@tisonkun thanks for your suggestion. Maintaining a matrix provides a chance to do a horizontal comparison within the same set of features. I think it provides value to both maintainers and users in the whole picture.

[tisonkun]

@momo-jun Yeah. If only there were volunteers who are willing to do it instead of "need developer resources".

Do you have a more concrete design and implementation? This proposal is far away from actionable now.

For example,

1. Where is the JSON file to be placed?
2. How to generate the result (table?) from the JSON file, especially what field we'd like to retain.
3. How and where is the result to display?
4. Currently, @Anonymitaet asked contributors to update the matrix sheet, how do we coordinate with these actions?
   See also [docs][java-client] Add sections for interceptor usage #17075 (review).

[momo-jun]

@tisonkun This is just a heads-up. I haven't got a concrete design or implementation plan yet.
The questions you listed are good ones that need to be clarified. I will add more details and discuss it in the community soon.

[momo-jun]

Move it to pending at this time point since there has been no feedback on the discussion thread yet and no engineering resources to build the page.
Will revisit it later.

[github-actions]

The issue had no activity for 30 days, mark with Stale label.

[momo-jun]

This PIP has been WIP since last week. I've updated the description and will add more details as soon as we have a bare bone to demo.

[hpvd]

great!
Tiny addition: Links in docs need to be updated to point to the new page
e.g. https://pulsar.apache.org/docs/next/client-libraries/#feature-matrix

[momo-jun]

@hpvd Yes - working on it apache/pulsar-site#546.

[hpvd]

awesome!