NuRaft

Raft implementation derived from the cornerstone project, which is a very lightweight C++ implementation with minimum dependencies, originally written by Andy Chen.

New features that are not described in the original paper, but required for the real-world use cases in eBay, have been added. We believe those features are useful for others outside eBay as well.

Features

In the original cornerstone

• Core Raft algorithm
  • Log replication & compaction
  • Leader election
  • Snapshot
  • Dynamic membership & configuration change
• Group commit & pipelined write
• User-defined log store & state machine support

New features added in this project

• Pre-vote protocol
• Leadership expiration
• Priority-based semi-deterministic leader election
• Read-only member (learner)
• Object-based logical snapshot
• Custom/separate quorum size for commit & leader election
• Asynchronous replication
• SSL/TLS support
• Parallel Log Appending
• Custom Commit Policy

How to Build

1. Install cmake and openssl:

• Ubuntu

  $ sudo apt-get install cmake openssl libssl-dev libz-dev

• OSX

  $ brew install cmake
  $ brew install openssl

• Windows

  • Download and install CMake.
  • Currently, we do not support SSL for Windows.

2. Fetch Asio library:

Using git submodule

$ git submodule update --init

Other ways to fetch:

• Linux & OSX: using the bash script

$ ./prepare.sh

• Windows: doing it manually
  • Clone Asio asio-1-24-0 into the project directory.

C:\NuRaft> git clone https://github.com/chriskohlhoff/asio -b asio-1-24-0

3. Build static library, tests, and examples:

• Linux & OSX

  $ mkdir build
  $ cd build
  build$ cmake ../
  build$ make

Run unit tests

build$ ./runtests.sh

• Windows:

  C:\NuRaft> mkdir build
  C:\NuRaft> cd build
  C:\NuRaft\build> cmake -G "NMake Makefiles" ..\
  C:\NuRaft\build> nmake

You may need to run vcvars script first in your build directory. For example (it depends on how you installed MSVC):

C:\NuRaft\build> c:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat

How to Use

Please refer to this document.

Example Implementation

Please refer to examples.

Benchmark

Please refer to tests/bench.

Quick Benchmark Results

Supported Platforms

• Ubuntu (tested on 14.04 -- 20.04)
• Centos (tested on 7)
• OSX (tested on 10.13 -- 12.3)
• Windows (built using MSVC 2019, not thoroughly tested)

Contributing to This Project

We welcome contributions. If you find any bugs, potential flaws and edge cases, improvements, new feature suggestions or discussions, please submit issues or pull requests.

Contact

• Jung-Sang Ahn jungsang.ahn@gmail.com

License Information

Copyright 2017-present eBay Inc.

Author/Developer: Jung-Sang Ahn

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

3rd Party Code

1. URL: https://github.com/datatechnology/cornerstone
   License: https://github.com/datatechnology/cornerstone/blob/master/LICENSE
   Originally licensed under the Apache 2.0 license.

2. URL: https://github.com/stbrumme/crc32
   Original Copyright 2011-2016 Stephan Brumme
   See Original ZLib License: https://github.com/stbrumme/crc32/blob/master/LICENSE

3. URL: https://github.com/greensky00/simple_logger
   License: https://github.com/greensky00/simple_logger/blob/master/LICENSE
   Originally licensed under the MIT license.

4. URL: https://github.com/greensky00/testsuite
   License: https://github.com/greensky00/testsuite/blob/master/LICENSE
   Originally licensed under the MIT license.

5. URL: https://github.com/greensky00/latency-collector
   License: https://github.com/greensky00/latency-collector/blob/master/LICENSE
   Originally licensed under the MIT license.

6. URL: https://github.com/eriwen/lcov-to-cobertura-xml/blob/master/lcov_cobertura/lcov_cobertura.py
   License: https://github.com/eriwen/lcov-to-cobertura-xml/blob/master/LICENSE
   Copyright 2011-2012 Eric Wendelin
   Originally licensed under the Apache 2.0 license.

7. URL: https://github.com/bilke/cmake-modules
   License: https://github.com/bilke/cmake-modules/blob/master/LICENSE_1_0.txt
   Copyright 2012-2017 Lars Bilke
   Originally licensed under the BSD license.