5 releases
0.1.4 | Sep 15, 2024 |
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0.1.3 | Sep 15, 2024 |
0.1.2 | Sep 14, 2024 |
0.1.1 | Sep 14, 2024 |
0.1.0 | Sep 14, 2024 |
#820 in Algorithms
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Jarl may be Just Another Raft Library, but it makes a point to be literally just another Raft library. There's no I/O, no standard library, no dependencies, no internal allocations, no async... literally just a state machine for managing consensus of a "virtual" cell.
The library is a single Rust file. As simple as it gets.
All Raft log state is managed in-memory.
The goal is to eventually have wrapping libraries which implement various transport integrations for using "off-the-shelf" (e.g. gRPC, OpenAPI, etc.) in an actual networked context. If we're feeling cheeky, we might even implement some unexpected IPC mechanisms (Raft over SMS anyone? What about Raft over S3? Serverless Raft‽).
lib.rs
:
Raft state machine
(Figure 4 from Raft paper)
Starting state = [Follower]
===========================
******************* ┌───────────┐ **************
* Times out, * │ ┼──>* Times out, *
* starts election *─────────>│ Candidate │ * tries new *
* * │ │<──* election *
******************* └─┬───────┬─┘ **************
^ v │
┌────┴─────┐ ********************* │
│ Follower │<──* Discovers current * │
└──────────┘ * leader or * │
^ * new term * │
│ ********************* v
│ ******************
******************** ┌────────┐ * Receives votes *
* Discovers server *<───┼ Leader │<───* from majority *
* with higher term * └────────┘ * of nodes *
******************** ******************