Kvstore

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Kvstore is a proxy based Redis cluster solution written in C++

Why Another Redis Cluster Solution

There are three open source Redis cluster solution as we known, so why another? Here are the main pain points:

• Twemproxy

  • can not resharding without restarting cluster
  • use only one thread so can not use multiple core in modern server machine

• Codis

  • write in go so there is some GC problem, this is undesirable for a cache service, cause most requests will be served in less than 1 millisecond
  • need to change Redis source code, it's painful to update to the latest Redis version
  • it used much more memory than the original Redis server, cause the key will be duplicated in the slot

• Redis Cluster

  • need to update redis client driver
  • do not widely deployed in production
  • do not support commands with multiple keys. e.g. MSET, MGET
  • it also used too much memory caused by duplicated key in the slot

Feature

• multiput thread to process client request

• pipeline support

• resharding without restarting cluster

• support most of redis commands, see not-support-redis-cmd for detailed commands

• support two mode:

  • cache mode

  -- Used as a pure cache, with redis sharding but without replication, so it can save half memory. For high availability, Redis node will be removed from the sharding nodes when it is failed

  • data-store mode

  -- Used as a data source, with redis sharding and replication. For high availability Slave Redis node will be promoted to master when the old master node failed

Architecture

<img width="500" height="500" src="doc/kvstore-arch.png"/>

Benchmark

Need to be done in the future

How to Build

Kvstore can be compile under Linux with epoll and MacOS X with kqueue, kvstore need a C++ compiler with C++11 feature, no other dependencies are required.

To compile the entire project, run the following commands

$ ./build.sh version 1.0

This will generate a package named kvstore-1.0.tar.gz in the current directory

How to Clean the Build

$./build.sh clean

How to Setup a Test Environment

Copy the build package to any directory, unzip it, run with command

$ ./kv_store.sh start

If no error report in this command, then kvstore cluster is already runing in this machine, with ** one kv_store_proxy and two redis-server sharding **. Use test_all to test that everything is OK

$ ./test_all 

After test, use this command to shutdown the cluster

$ ./kv_store.sh stop  

Have Fun!