liyinhgqw / memcache_client

Memcache client for golang with consistent hashing implemented

Memcache Client with Consistent Hashing

Overview

This is memcache client library for Golang, with consistent hashing implemented. We don't try hacking the memcache server code with Chord, since we want it to stay original.

Installing

$ go get github.com/liyinhgqw/memcache

Example

import (
    "fmt"
    "github.com/liyinhgqw/memcache"
)

func main() {
    // register server addresses and weights
    cl := memcache.NewChClient([]string{"localhost:11211", "localhost:11212"}, []uint32{1, 1})
    cl.Set(&memcache.Item{
        Key:   "a",
        Value: []byte("AAA"),
    })
    cl.Set(&memcache.Item{
        Key:   "b",
        Value: []byte("BBB"),
    })
    items, err := cl.GetMulti([]string{"a", "b"})
    if err != nil {
        fmt.Println(err)
    }
    for k, v := range items {
        fmt.Println(k, v)
    }
}

You can see memcache_test.go for more usage.

Limitation

Since we don't mess with the memcache server code using Chord algorithm, there are some limitations:

• All clients Must use the same server list and weights.
• Add or delete a server is okay, cache miss may happen for some keys.
• Never ever delete an added server, otherwise inconsistency may happen.

Reference

• simple hash memcache client
• APE memcache client usage
• command protocol