[Deliverable] Review usage of content topics in Status Communities protocol

[chair28980]

The usage of content topics in Status is aligned with Wakuv1. Waku v2 comes with a new recommended format that enables auto-sharding.

Moreover, single Status users currently use a high number of content topics, which may have an impact on performance of req-res protocols such as store and filter.

Such impact is to be measured in a previous milestone by Vac DST.

The output of this deliverable should be an RFC update on how content topics should be used, backed with simulations when performance improvement is expected.

It should include migration strategy and potential impact on the product.

Implementation Details

This is planned to be done in a phase-wise manner:

1. Identify and update communities content-topic usage in status app to match current filter criteria. Discussion and analysis in https://forum.vac.dev/t/status-communities-review-and-proposed-usage-of-waku-content-topics/335/29
2. Come up with recommendations as to how filter-criteria can be changed/updated for communities.

Phase-1 has 2 sub-phases as per <>. The idea is the PRs for both phases would be made ready one after the other and decision to release phase1b(n+2) is left to status app (probably based on number of users that are still using version n)

• Update code to a version n+1 to send messages to a single content-topic in community for all chats, but listen on all existing content-topics. This is being tracked in feat_: use a single content-topic for all community chats status-im/status-go#5864

• Update the code to a version n+2 which would only use single content-topic for both sending/receiving of messages within a community. This would break compatibility with versions n and before of the status app.

Phase-2 TBD (Not sure at this point if it can be part of same deliverable or can be taken up as subsequent deliverable)