1、介绍 repcached是日本人开发的实现memcached复制功能,它是一个单 master单 slave的方案,但它的master/slave都是可读写的,而且可以相互同步,如果 master坏掉, slave侦测到连接断了,它会自动 listen而成为 master;而如果 slave坏掉, master也会侦测到连接断,它就会重新 listen等待新的 slave加入 repcached的安装有两种方式,一种是直接对应的repcached版本,其包含repcached和memcached两个包。直接安装该版本, 即完成了repcached和memcached的安装,不用再独立安装memcached。另一种是一个独立的repcached补丁包,将其作为 memcached的补丁,需要单独安装memcached,然后再为其打上该补丁。在多数情况下,都采用第一种安装方法。 2、实验环境:两台测试机,ip分别为192.168.1.105和192.168.1.106,在其上安装repcached,并设置两台服务器互为主从。 使用整合了repcached和memcached的版本安装:安装libevent:
-stable.tar.gzcd libevent--stable./configure --prefix=/usr/local/libevent && make && make install
安装repcached:
wget https://github.com/usecide/repcached/archive/master.zipunzip memcached-repcached.zipcd memcached-repcached./autogensh./configure --prefix=/usr/local/repcached --enable-64bit --enable-replication --with-libevent=/usr/local/libeventmake && make install
使用repcached补丁包安装的方法:下载补丁包,目前补丁包最高对应的memcached是1.2.8
wget http://sourceforge.net/projects/repcached/files/repcached/2.2.1-1.2.8/repcached-2.2.1-1.2.8.patch.gz/download下载对应版本的memcachedwget https://memcached.googlecode.com/files/memcached-1.2.8.tar.gz.tar.gz-.patch.gzcd memcached--.patch./configure --prefix=/usr/local/memcached --enable-64bit --enable-replication --with-libevent=/usr/local/libeventmake && make install如果在编译时出现如下错误:memcached.c: Infunction ‘add_iov’:memcached.c::error: ‘IOV_MAX’ undeclared (first use in this function)memcached.c::error: (Each undeclared identifier is reported only oncememcached.c::error: for each function it appears in.)]: ***[memcached-memcached.o] Error]: Leavingdirectory `/root/memcached/memcached--repcached-']: ***[all-recursive] Error]: Leavingdirectory `/root/memcached/memcached--repcached-'则需要手动修改源文件memcached.c将 /* FreeBSD 4.x doesn't have IOV_MAXexposed. */ #ifndef IOV_MAX #if defined(__FreeBSD__) ||defined(__APPLE__) # define IOV_MAX #endif #endif修改为: /* FreeBSD 4.x doesn't have IOV_MAXexposed. */ #ifndef IOV_MAX /*#if defined(__FreeBSD__) ||defined(__APPLE__)*/ # define IOV_MAX #endif /*#endif*/
启动:分别在两台机上启动repcached如下:105:
/usr/local/repcached/bin/memcached -u memcached -l -m -x -d
106:
/usr/local/repcached/bin/memcached -u memcached -l -m -x -d
参数简单说明:
-u:指定启动memcached的用户,该用户需要事先创建-l:指定memcached监听的本地ip地址-p:指定memcached监听的本地的tcp端口,默认为11211-m:指定memcached启动后占用的内存空间大小,单位为M-x:指定repcached的master的ip地址,需要从master同步数据-X:指定从master同步数据时的端口,默认为11212-d:将其作为守护进程放入后台运行
测试:在105上进行如下操作:
telnetset key1hello
在106上查看:
telnetget key1当看到显示VALUE key1hello即代表数据成功实现同步,反之测试亦然。