Note: This project is of alpha quality. APIs are still in some flux, but they are ready for you to play with them. A stable version will be released when we feel it is ready.
Problem and Importance
When building a distributed system one principal goal is often to build in fault-tolerance. That is, if one particular node in a network goes down, or if there is a network partition, the entire cluster does not fall over. The cluster of nodes taking part in a distributed consensus protocol must come to agreement regarding values, and once that decision is reached, that choice is final.
Distributed Consensus Algorithms often take the form of a replicated state machine and log. Each state machine accepts inputs from its log, and represents the value(s) to be replicated, for example, a hash table. They allow a collection of machines to work as a coherent group that can survive the failures of some of its members.
Two well known Distributed Consensus Algorithms are Paxos and Raft. Paxos is used in systems like Chubby by Google, and Raft is used in things like
etcd. Raft is generally seen as a more understandable and simpler to implement than Paxos, and was chosen for this project for this reason.
- Raft Crate Documentation
- The Raft site
- The Secret Lives of Data - Raft
- Raft Paper
- Raft Dissertation
- Raft Refloated
For Linux, BSD, or Mac. Windows is not supported at this time. We are willing and interested in including support, however none of our contributors work on Windows. Your PRs are welcome!
You will need the Rust compiler:
curl -L https://static.rust-lang.org/rustup.sh > rustup chmod +x rustup ./rustup --channel=nightly
We require the
nightlychannel for now.
This should install
rustc. Next, you'll need
capnp to build the
messages.canpnp file . It is suggested to use the git method
git clone https://github.com/sandstorm-io/capnproto.git cd capnproto/c++ ./setup-autotools.sh autoreconf -i ./configure make -j6 check sudo make install
Finally, clone the repository and build it:
git clone firstname.lastname@example.org:Hoverbear/raft-rs.git && \ cd raft-rs && \ cargo build
Note this is a library, so building won't necessarily produce anything useful for you unless you're developing.
You can run a single-node
register example like this:
RUST_LOG=raft=debug cargo run --example register server 1 1 127.0.0.1:8080
There are currently examples showing:
- Register: A single shared, replicated buffer for storing some data. Uses
- Hashmap: A replicated hash table that stores
Strings as keys. Uses
For a multi-node example (
hashmap shown for variety), make sure to include all the peers on all instances:
# Node 1 RUST_LOG=raft=debug cargo run --example hashmap server 1 1 127.0.0.1:8080 2 127.0.0.1:8081 # Node 2 RUST_LOG=raft=debug cargo run --example hashmap server 2 1 127.0.0.1:8080 2 127.0.0.1:8081
We'd love it if you contributed your own or expanded on ours!
You can run the
raft crate's full bank of tests with all debug output like so:
RUST_BACKTRACE=1 RUST_LOG=raft=debug cargo test -- --nocapture
For something more terse use
First timer with Git? Check this out for some help!!
We use Homu for merging requests. This means we cannot merge your code unless it passes tests!