Apache Ratis (Incubating)

Clone this repo:
  1. ced7dbf RATIS-649. Add metrics related to ClientRequests. Contributed by Aravindan Vijayan. by Shashikant Banerjee · 13 hours ago master
  2. ef12b1f RATIS-676. Add a metric in RaftServer to track the Log Commit Index. Contributed by Aravindan Vijayan. by Shashikant Banerjee · 14 hours ago
  3. f36acab RATIS-717. NPE thrown on the follower while instantiating RaftLeaderMetrics. Contributed by Aravindan Vijayan. by Shashikant Banerjee · 14 hours ago
  4. d11320d RATIS-706. Dead lock in GrpcClientRpc. Contributed by Tsz Wo Nicholas Sze. by Lokesh Jain · 30 hours ago
  5. 9cbf1ef RATIS-691. Fix checkstyle violations in ratis-logservice. Contributed by Dinesh Chitlangia by Tsz Wo Nicholas Sze · 2 days ago

Apache Ratis

Apache Ratis is a Java library that implements the Raft protocol [1], where an extended version of the Raft paper is available at https://raft.github.io/raft.pdf. The paper introduces Raft and states its motivations in following words:

Raft is a consensus algorithm for managing a replicated log. It produces a result equivalent to (multi-)Paxos, and it is as efficient as Paxos, but its structure is different from Paxos; this makes Raft more understandable than Paxos and also provides a better foundation for building practical systems.

Ratis aims to make Raft available as a java library that can be used by any system that needs to use a replicated log. It provides pluggability for state machine implementations to manage replicated states. It also provides pluggability for Raft log, and rpc implementations to make it easy for integration with other projects. Another important goal is to support high throughput data ingest so that it can be used for more general data replication use cases.


  1. Diego Ongaro and John Ousterhout, In Search of an Understandable Consensus Algorithm, 2014 USENIX Annual Technical Conference (USENIX ATC 14) (Philadelphia, PA), USENIX Association, 2014, pp. 305-319.