*** Note: there are plans to build and deploy a new version of state sync. As such, this version (v1) will be deprecated in the near future. See this issue for more information. ***

State synchronizer (State sync)

State sync is a component that helps Diem nodes advance local blockchain ledger state by requesting and sharing transactions between peers. This helps nodes to synchronize with the most up-to-date state of the blockchain (e.g., if they fall behind or are freshly deployed).

Overview

Refer to the State Sync Specification for a high-level overview and description of State Sync.

Implementation details

This crate contains a state sync implementation as described in the specification mentioned above. The files of note in this crate are:

• bootstrapper.rs: the wrapper struct for creating state sync instances and local clients (client.rs) to those instances.
• chunk_request.rs & chunk_response.rs: the definitions of the messages sent between Diem nodes when making state sync requests and responses.
• coordinator.rs: the primary state sync runtime that processes messages (e.g., from other Diem nodes) and reacts appropriately.
• executor_proxy.rs: the interface between the state sync coordinator and both storage and execution.
• request_manager.rs: the actor that manages the network requests and responses between peers.

How is this module organized?

state-sync
|- src                         # Source code and unit tests
|- tests/                      # Integration tests