paxos

The paxos project is an implementation of the paxos consensus protocol. It provides a library for maintaining consistency within a distributed system.

Build

You will need a compiler with full C++11 support. You can then use CMake to generate MakeFiles for this project.

$ mkdir build && cd build
$ cmake ..
$ make && ./unittests/all_unittests

Setup

Create a paxos.replicaset file in the directory where the parliament will run.

$ echo 127.0.0.1:8080 >> paxos.replicaset

Usage

Create a parliament and then send proposals to vote upon.

#include <paxos/parliament.hpp>

int main(void)
{
    //
    // Create a parliament group.
    //
    paxos::Parliament p(paxos::Replica("127.0.0.1", 8080));

    //
    // Sends a proposal to vote on.
    //
    p.SendProposal("Pinky says, 'Narf!'");
}

Each passed proposal is appended to the paxos.ledger. If you want to process the decree, you must create your parliament with a decree handler.

    paxos::Parliament p(
        //
        // Our replica identity in the parliament.
        //
        paxos::Replica("127.0.0.1", 8080),

        //
        // Path of directory to contain state information.
        //
        ".",

        //
        // Decree handler to process passed decrees.
        //
        [](std::string decree) { std::cout << "Execute: " << decree << "\n"; });

As soon as the instance sees the decree passed, it will execute the decree handler and append the decree to the ledger.

References

• The Part-Time Parliament