Twemproxy是Twitter开源的Redis代理，借助其可实现稳定的Redis分布式方案，相对于官方较新的Redis Cluster架构，容量伸缩较麻烦。
安装比较简单，注意可能会遇到autoconf版本低的问题。
安装依赖库
# yum install autoconf libtool -y
下载最新版本
https://github.com/twitter/twemproxy/releases
编译安装twemproxy
# tar zxf twemproxy-0.4.1.tar.gz
# cd twemproxy-0.4.1
遇到autoconf版本低的报错
# autoreconf -fvi
...
configure.ac:8: error: Autoconf version 2.64 or higher is required
下载较高版本的autoconf
http://ftp.gnu.org/gnu/autoconf/autoconf-2.69.tar.gz
编译安装autoconf，并覆盖低版本文件
# ./configure
# make
# make install
# cp /usr/local/bin/autoconf /usr/bin/
# cp /usr/local/bin/autoreconf /usr/bin/
重新安装
# autoreconf -fvi
# ./configure --prefix=/usr/local/twemproxy
# make
# make install
twemproxy的重要特性
1. Maintains persistent server connections.
2. Keeps connection count on the backend caching servers low.
3. Enables pipelining of requests and responses.
4. Supports multiple server pools simultaneously.
5. Observability via stats exposed on the stats monitoring port.
6. Supports multiple hashing modes including consistent hashing and distribution.
配置文件，其中端口6379和6389为2个Redis实例。
$ cat kp.conf
kp:
listen: 127.0.0.1:7379
hash: fnv1a_64
distribution: ketama
timeout: 100
auto_eject_hosts: true
server_retry_timeout: 2000
server_failure_limit: 2
redis: true
redis_auth: abcdefg
servers:
- 127.0.0.1:6379:1
- 127.0.0.1:6389:1
启动twemproxy
# nutcracker --daemonize --verbose=11 --output=nut.log --conf-file=kp.conf --stats-port=22222 --pid-file=nut.pid
登陆twemproxy
$ redis-cli -p 7379 -a abcdefg
127.0.0.1:7379> get hello
"redis"
127.0.0.1:7379> set twe proxy
OK
127.0.0.1:7379> dbsize
Error: Server closed the connection
获取twemproxy状态
$ curl -GET http://127.0.0.1:22222
{"service":"nutcracker", "source":"51", "version":"0.4.1", "uptime":22766,
...
}
若感兴趣可关注订阅号”数据库最佳实践”(DBBestPractice).
