Implement ADR 032: Typed Events

[akhilkumarpilli]

Summary

Implement ADR 032: Typed Events as documented in #7474

Pros

• Improves consistency of events implementation which helps for writing event driven applications.
• Simplifies the process of consuming events.
  ref: https://github.com/cosmos/cosmos-sdk/blob/master/docs/architecture/adr-032-typed-events.md#positive
  ref: Detailed code example of publishing events

Cons

• Includes lot of marshalling and unmarshalling in implementation.
  ref: x/ibc: implement ADR 032 typed events #7762 (review)

Roadmap

• init: Implement ADR 032 typed events #7564 Implement EmitTypedEvent and ParseTypedEvent functions

• Modules: create proto Events for modules, replace all EmitEvents with EmitTypedEvents

  • x/auth
  • x/bank
  • x/crisis
  • x/distribution
  • x/evidence
  • x/gov
  • x/ibc (x/ibc: implement ADR 032 typed events #7762)
  • x/mint
  • x/slashing
  • x/staking

• Update events documentation per module

[colin-axner]

Resolve road blocks outlined in this comment

[amaury1093]

Hey @akhilkumarpilli, what's the status of this issue? What are the next steps so that all modules only emit typed events?

[akhilkumarpilli]

Hey @akhilkumarpilli, what's the status of this issue? What are the next steps so that all modules only emit typed events?

This issue tendermint/tendermint#5978 needs to be resolved first. Once after that, we can start implementing ADR-032 in all modules.

[tac0turtle]

This issue tendermint/tendermint#5978 needs to be resolved first. Once after that, we can start implementing ADR-032 in all modules.

We will be providing a postgres indexer, can this be done through that?

As for the current indexer, we may say it is feature complete and not work on it anymore.

[akhilkumarpilli]

This issue tendermint/tendermint#5978 needs to be resolved first. Once after that, we can start implementing ADR-032 in all modules.

We will be providing a postgres indexer, can this be done through that?

As for the current indexer, we may say it is feature complete and not work on it anymore.

Hope it will support. We will try to implement and test this once after postgres indexer is integrated. Thanks.

[clevinson]

@marbar3778 can we discuss this next friday in our architecture call to align on if there's any tendermint blockers here?

[albertchon]

I've been doing some benchmarking with emitting very large typed events and have found that the TypedEventToEvent takes a significant amount of time to run due to high amount of allocations in the ProtoMarshalJSON call.

Can a more efficient solution for typed events be worked on?

[aaronc]

Based on on last architecture call, it sounds like the path forward for this may be to create a custom event system within the SDK that bypasses Tendermint. With that approach, event indexing could happen in a separate thread reducing the impact of marshaling JSON. A custom approach would also allow us to tune things to the data model we're using (i.e. dealing with quotes properly).

[clevinson]

@akhilkumarpilli We'd like to discuss this at our next architecture call on Friday July 2. @anilcse will invite you to that call.

[akhilkumarpilli]

@akhilkumarpilli We'd like to discuss this at our next architecture call on Friday July 2. @anilcse will invite you to that call.

@clevinson I am not sure whether I can be available for call as I need to undergo a minor surgery on friday. @anilcse will help in discussions regarding typed events incase of my absence.

[francas]

Hi, I have a question on Typed Events.

I noticed because of unneeded marshalling we get strangely quoted values in the event log:

- attributes:
    - key: appId
      value: '"62d449fd27193b2aff8aeee5322381b40ed05a3cd2904c2de4b2c65983372882"'
    type: poc.poc.EventRegisterApp

Main reason I'm asking is because we're subscribing to those events and now have to "unquote" them for no reason. Maybe there is another way of subscribing that lets read Typed Events somehow. But current one (via RPC - Tendermint RPC) gives access to already parsed (quoted) data.

[anilcse]

@tac0turtle should we remove TypedEvents as we are not really using them widely?

[julienrbrt]

@tac0turtle should we remove TypedEvents as we are not really using them widely?

Typed events are still supported in core (https://github.com/cosmos/cosmos-sdk/blob/main/core/event/service.go#L19-L22), so we shouldn't kill them. We just don't need to migrate all existing modules to typed event.

[anilcse]

What about this: https://github.com/cosmos/cosmos-sdk/blob/main/types/events.go#L21-L22

[julienrbrt]

What about this: https://github.com/cosmos/cosmos-sdk/blob/main/types/events.go#L21-L22

That is equivalent to the snippet above.