Redcon

Redis compatible server framework for Go

Features

• Create a Fast custom Redis compatible server in Go
• Simple interface. One function ListenAndServe and two types Conn & Command
• Support for pipelining and telnet commands
• Works with Redis clients such as redigo, redis-py, node_redis, and jedis
• TLS Support
• Compatible pub/sub support
• Multithreaded

This library is also available for Rust and C.

Installing

go get -u github.com/tidwall/redcon

Example

Here's a full example of a Redis clone that accepts:

• SET key value
• GET key
• SETNX key value
• DEL key
• PING
• QUIT
• PUBLISH channel message
• SUBSCRIBE channel

You can run this example from a terminal:

go run example/clone.go

package main

import (
	"log"
	"strings"
	"sync"

	"github.com/tidwall/redcon"
)

var addr = ":6380"

func main() {
	var mu sync.RWMutex
	var items = make(map[string][]byte)
	var ps redcon.PubSub
	go log.Printf("started server at %s", addr)
	err := redcon.ListenAndServe(addr,
		func(conn redcon.Conn, cmd redcon.Command) {
			switch strings.ToLower(string(cmd.Args[0])) {
			default:
				conn.WriteError("ERR unknown command '" + string(cmd.Args[0]) + "'")
			case "ping":
				conn.WriteString("PONG")
			case "quit":
				conn.WriteString("OK")
				conn.Close()
			case "set":
				if len(cmd.Args) != 3 {
					conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
					return
				}
				mu.Lock()
				items[string(cmd.Args[1])] = cmd.Args[2]
				mu.Unlock()
				conn.WriteString("OK")
			case "get":
				if len(cmd.Args) != 2 {
					conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
					return
				}
				mu.RLock()
				val, ok := items[string(cmd.Args[1])]
				mu.RUnlock()
				if !ok {
					conn.WriteNull()
				} else {
					conn.WriteBulk(val)
				}
			case "setnx":
				if len(cmd.Args) != 3 {
					conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
					return
				}
				mu.RLock()
				_, ok := items[string(cmd.Args[1])]
				mu.RUnlock()
				if ok {
					conn.WriteInt(0)
					return
				}
				mu.Lock()
				items[string(cmd.Args[1])] = cmd.Args[2]
				mu.Unlock()
				conn.WriteInt(1)
			case "del":
				if len(cmd.Args) != 2 {
					conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
					return
				}
				mu.Lock()
				_, ok := items[string(cmd.Args[1])]
				delete(items, string(cmd.Args[1]))
				mu.Unlock()
				if !ok {
					conn.WriteInt(0)
				} else {
					conn.WriteInt(1)
				}
			case "publish":
				if len(cmd.Args) != 3 {
					conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
					return
				}
				conn.WriteInt(ps.Publish(string(cmd.Args[1]), string(cmd.Args[2])))
			case "subscribe", "psubscribe":
				if len(cmd.Args) < 2 {
					conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
					return
				}
				command := strings.ToLower(string(cmd.Args[0]))
				for i := 1; i < len(cmd.Args); i++ {
					if command == "psubscribe" {
						ps.Psubscribe(conn, string(cmd.Args[i]))
					} else {
						ps.Subscribe(conn, string(cmd.Args[i]))
					}
				}
			}
		},
		func(conn redcon.Conn) bool {
			// Use this function to accept or deny the connection.
			// log.Printf("accept: %s", conn.RemoteAddr())
			return true
		},
		func(conn redcon.Conn, err error) {
			// This is called when the connection has been closed
			// log.Printf("closed: %s, err: %v", conn.RemoteAddr(), err)
		},
	)
	if err != nil {
		log.Fatal(err)
	}
}

TLS Example

Redcon has full TLS support through the ListenAndServeTLS function.

The same example is also provided for serving Redcon over TLS.

go run example/tls/clone.go

Benchmarks

Redis: Single-threaded, no disk persistence.

$ redis-server --port 6379 --appendonly no

redis-benchmark -p 6379 -t set,get -n 10000000 -q -P 512 -c 512
SET: 941265.12 requests per second
GET: 1189909.50 requests per second

Redcon: Single-threaded, no disk persistence.

$ GOMAXPROCS=1 go run example/clone.go

redis-benchmark -p 6380 -t set,get -n 10000000 -q -P 512 -c 512
SET: 2018570.88 requests per second
GET: 2403846.25 requests per second

Redcon: Multi-threaded, no disk persistence.

$ GOMAXPROCS=0 go run example/clone.go

$ redis-benchmark -p 6380 -t set,get -n 10000000 -q -P 512 -c 512
SET: 1944390.38 requests per second
GET: 3993610.25 requests per second

Running on a MacBook Pro 15" 2.8 GHz Intel Core i7 using Go 1.7

Contact

Josh Baker @tidwall

License

Redcon source code is available under the MIT License.