EPIC: Baseapp++

[tac0turtle]

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Summary

Tendermint team has been working on a refactor of the abci layer to enable more use cases. This has been a requested feature by many users and will be a focus of the sdk team once a release of 0.36 is cut and SDK team has completed app wiring migration.

More Information can be found on the design here: https://github.com/tendermint/tendermint/tree/master/spec/abci%2B%2B

Phase 1

Phase 1 of baseapp++ will be focused on prepare proposal and process proposal.

• [x] #12770
• [x] #13150
• [x] #13151
• [ ] Release baseapp

Phase 2

Phase 2 of baseapp++ will commence once tendermint releases a version of abci with vote extensions and finalise block

• [ ] ADR for vote extensions and finalise block
• [ ] Implement vote extensions
• [ ] Implement finalize block
• [ ] Release Baseapp

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For Admin Use

• [x] Not duplicate issue
• [ ] Appropriate labels applied
• [ ] Appropriate contributors tagged
• [ ] Contributor assigned/self-assigned

[p0mvn]

Is the plan to switch to the newly introduced "same block execution" or keep using "next block execution"?

Asking to learn - why would we prefer one over the other in the SDK?

[alexanderbez]

I think the idea here @p0mvn is to refactor/update the BaseApp implementation to implement the new ABCI++ interface and deprecate or remove the old methods.

[tac0turtle]

Is the plan to switch to the newly introduced "same block execution" or keep using "next block execution"?

Asking to learn - why would we prefer one over the other in the SDK?

We will continue to use next-block execution because the sdk is built with the off by one approach of delayed execution (next-block execution), if we move to immediate execution (same-block execution) we would need to refactor quite a few things

[itsdevbear]

The ability to do same block execution would be nice, how bad would the refactor be @marbar3778 ?

[tac0turtle]

immediate execution would be a fairly hefty rewrite, I believe, as staking and other modules assume H+1. Optimistic execution, where we start execution in the process proposal phase is a lot lighter of a lift

[alexanderbez]

Yeah it's not trivial because as @marbar3778 pointed out there are various places in the SDK where we have this "off by 1" assumption, so it's not just a few changes to baseapp :-/

In any case, we're proposing the execute the entire block in ProcessProposal, where apps (if they decide) can actually execute this in parallel with Tendermint's voting rounds.

[itsdevbear]

Immediate execution seems like the "more correct" way to do things long term though? Should improve UX a lot since chain will feel "snappier" when using. Less important in a world of sub second block times, but still seems important?

I know this would mess with the distributor for sure, but I presume also evidence crisis etc. would need a big refactor. Would optimistic processing get close to similar performance?

[alexanderbez]

Long term? Yes. It's not on our immediate roadmap though as ABCI++ integration is more important along with store improvements as that is the biggest pain point atm. People don't really mind the current execution model, granted it is annoying.