What is Godis?

Godis is simple implementation of Redis-like in-memory cache written in Go.

Features

• A key-value storage that supports strings, lists and hashes as stored values.

• Automatic expiration of a key. TTL can be optionally assigned to a key.

• The following commands are supported:

  common	string	list	hash
  command	get	llen	hkeys
  type	set	lindex	hexists
  keys		lpop	hget
  exists		lpush	hgetall
  del		rpop	hset
  expire		rpush	hdel
  expireat		lset
  pexpire
  pexpireat
  ttl
  pttl
  persist

  The commands have the same signature and work exactly the same as corresponding commands in Redis below version 2.4 (Godis does not support multikey and multivalue commands).

• Both REdis Serialization Protocol (RESP) and Inline Commands Protocol are supported. Thus simple telnet and redis-cli clients can be used to play with Godis. Moreover, performance can be tested with redis-benchmark.

• Golang API client

• Write-ahead logging based persistence. Log compaction is not yet implemented and format of the log is not optimized due to reasons of simplicity.

Installation

To build Godis as a Docker image install and run Docker and use the following command:
docker build -t godis github.com/ekundo/godis

Playing with Godis

As a first step start Godis server with:
docker run -v $(pwd):/work -p 2121:2121 -it --rm godis

Then send commands to server using any tcp client like telnet

$ telnet 127.0.0.1 2121
set foo bar
+OK
get foo
$3
bar

Although redis-cli is the best choice:

$ redis-cli -p 2121 -h 127.0.0.1
redis> set foo bar
OK
redis> get foo
"bar"

Use command to get the list of available commands. Details of each command from the list can be found at redis command guide.

Performance testing results

Below are the testing results performed on my MacBook Pro 13 (Intel Core i5 2.9 GHz, 8 GB LPDDR3, SSD)

$ redis-benchmark -p 2121 -r 65536 -q -t SET,GET,LPUSH,RPUSH,LPOP,RPOP,HSET
SET: 21640.34 requests per second
GET: 26116.48 requests per second
LPUSH: 23342.67 requests per second
RPUSH: 22925.26 requests per second
LPOP: 24313.15 requests per second
RPOP: 25227.04 requests per second
HSET: 19105.85 requests per second

Test result are compared with such of original Redis server:

redis-benchmark -r 65536 -q -t SET,GET,LPUSH,RPUSH,LPOP,RPOP,HSET
SET: 50994.39 requests per second
GET: 51072.52 requests per second
LPUSH: 52938.06 requests per second
RPUSH: 52328.62 requests per second
LPOP: 52548.61 requests per second
RPOP: 51867.22 requests per second
HSET: 51519.84 requests per second