This is a series of projects on a key-value storage system built with the Raft consensus algorithm. These projects are inspired by the famous [MIT 6.824](http://nil.csail.mit.edu/6.824/2018/index.html) course, but aim to be closer to industry implementations. The whole course is pruned from [TiKV](https://github.com/tikv/tikv) and re-written in Go. After completing this course, you will have the knowledge to implement a basic key-value storage fault-tolerance service with distributed transaction support and a better understanding of TiKV implementation.
**Important note: This course is still in developing, and the document is incomplete.** Any feedback and contribution is greatly appreciated. Please see help wanted issues if you want to join in the development.
Then make sure you have installed [go](https://golang.org/doc/install) >= 1.13 toolchains. You should also have installed `make`.
Now you can run `make` to check that everything is working as expected. You should see it runs successfully.
### Overview of the code

Same as the architect TiDB + TiKV + PD that separates the storage and computation, TinyKV only focuses on the storage layer of a distributed database system. If you are also interested in SQL layer, see [TinySQL](https://github.com/pingcap-incubator/tinysql). Besides that, there is a component called TinyScheduler as a center control of the whole TinyKV cluster, which collects information from the heartbeats of TinyKV. After that, the TinyScheduler can generate some scheduling tasks and distribute them to the TinyKV instances. All of them are communicated by RPC.
The whole project is organized into the following directories:
-`kv`: implementation of the TinyKV key/value store.
-`proto`: all communication between nodes and processes uses Protocol Buffers over gRPC. This package contains the protocol definitions used by TinyKV, and generated Go code for using them.
-`raft`: implementation of the Raft distributed consensus algorithm, used in TinyKV.
-`scheduler`: implementation of the TinyScheduler which is responsible for managing TinyKV nodes and for generating timestamps.