Page History

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Problem

Previous assumptions about Iroha Network and Web API in general were usage of iroha-client with encapsulation of underlying (plain TCP) protocols.
New needs from dependent projects require discussion of these assumptions and decision how to work with iroha network.

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Iroha Bridge module provides an ability to connect different blockchains together and needs an ability to communicate between both sides via web interface.

Current Iroha approach is a proprietary TCP based protocol encapsulated inside `iroha_network` crate. `iroha_client` crate uses `iroha_network` inside and should be  used itself by other applications including another other blockchain solutions like `Polkadot`.

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In this discussion we should make a decision - will this situation impact our current solution?

Introduction

To make a decision we should formalize the problem, allocate and analyze possible solutions.

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Solution

Requirements from Iurii Vinogradov

• We need Http compatible interface on Iroha side

• We need and Http compatible client library which can support all Iroha user ISI, Query, streams.

• HTTP client library should be implemented in Rust for use from Substrate.

• We need JS compatible library to interact with Iroha2

• The deadline is the middle of August.

Problem

Clients with only high level networking support (HTTP/WebSocket) need to do additional development for Iroha Bridge integration and may even have some runtime specific restrictions which will make it impossible.

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Which can be rephrased as:

• Iroha should provide HTTP API for:
  • Iroha Special Instructions Submission
  • Iroha Queries Execution 
  • Iroha Cloud Events Consumption
• Iroha's Rust HTTP client library for Substrate's Off-chain Workers should be developed
• Iroha's JS client library should be developed

Decisions

• Iroha Bridge module will provide additional HTTP Endpoints on top of existing Torii Endpoints
• JS library will use HTTP Endpoints and will not depend on Iroha codebase
• Rust HTTP Client will be implemented as a separate `no-std` crate
• Cloud Events will be implemented via HTTP instead of WebSocket because of Substrate's restrictions

Alternatives

• Iroha provides HTTP API out-of-the-box
  • Need to define scope
  • Need to not duplicate peer to peer communications logic
• Dedicated HTTP server module on Iorha2 Iroha 2 not included in the core but have an ability to proxy all ISI and queries if needed.
• Iroha Bridge module provides HTTP wrapper on top of Iroha API (on the Peer side)
  • Need to define scope
  Iroha Bridge has an additional application as a proxy on top of Iroha API (as a standalone app or service mesh)
• Every client is responsible for HTTP Adapters

Protocol

Also, we need to define protocol for HTTP messages. We have the next proposal:

• JSON RPC - seems like a clearly define protocol able to generate code for multiple platforms.

Action items

Concerns

• Any change in `iroha_network` algorithms and Iroha entities format will break clients
• HTTP implementation of Cloud Events may be very slow and impact the throughput of the whole ledger

Assumptions

• Bridge clients will use Substrate's Off-chain Workers with an ability to communicate over HTTP only
• JS client has additional restrictions
• All clients will use scale encoding

Risks

• Backward compatibility breakage `[7; 9]`
• Performance regress `[8; 5]`
• Scale encoding will be hard to implement for non-rust clients `[3;5]`

Action items

•  Iurii VinogradovSalakhiev Kamil Makoto Takemiya review requirements
•  Iurii Vinogradov ask for comments from clients' developers
•  Nikita Puzankov design the result of the discussion