欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  IT编程

memcached复制-repcached

程序员文章站 2022-06-24 21:00:58
1.前言 由于memcached把数据都放到内存里,因此性能是极高的,正因为如此,不可避免会造成数据丢失,repcached就派上用场了,它可以实现memcached的主从复制 2.安装repcached 下面采用memcached和repcached一起安装的方式 $ cd usr/local/s ......
1.前言

由于memcached把数据都放到内存里,因此性能是极高的,正因为如此,不可避免会造成数据丢失,repcached就派上用场了,它可以实现memcached的主从复制

2.安装repcached

下面采用memcached和repcached一起安装的方式

$ cd usr/local/src
$ wget https://downloads.sourceforge.net/project/repcached/repcached/2.2.1-1.2.8/memcached-1.2.8-repcached-2.2.1.tar.gz
$ tar -zxvf memcached-1.2.8-repcached-2.2.1.tar.gz
$ cd memcached-1.2.8-repcached-2.2.1
$ ./configure --enable-replication --program-transform-name=s/memcached/repcached/
error: 'IOV_MAX' undeclared (first use in this function) #centos编译会报这个错,需要修改代码
$ vi memcached.c
/* FreeBSD 4.x doesn't have IOV_MAX exposed. */
#ifndef IOV_MAX
#if defined(__FreeBSD__) || defined(__APPLE__) 
#define IOV_MAX 1024
#endif
#endif
$ make && make install
3.测试复制

为了方便,下面的测试是在同一台机器上开启两个端口来进行主从复制的

$ memcached -p 11211 -d -v #-d表示守护进程 -v是打印日志
replication: listen
replication: accept

#按下Ctrl+c,在本机添加从服务器,-x是主cache的ip
$ memcached -p 11212 -d -x 192.168.56.10 -v
replication: connect (peer=192.168.56.10:11212)
replication: marugoto copying
replication: start

#分别连接测试主从同步
$ telnet localhost 11211
Trying ::1...
Connected to localhost.
Escape character is '^]'.
set myname 0 0 6
pigfly
STORED
quit
Connection closed by foreign host.
$ telnet localhost 11212
Trying ::1...
Connected to localhost.
Escape character is '^]'.
get myname
VALUE myname 0 6
pigfly #从cache已经能获取到主cache的数据了,说明主复制到从没有问题
END
set age 0 0 2
23
STORED
quit
Connection closed by foreign host.
$ telnet localhost 11211
Trying ::1...
Connected to localhost.
Escape character is '^]'.
get age
VALUE age 0 2
23 #这里主cache也拿到了从cache的数据,说明从复制到主也没问题
END
quit
Connection closed by foreign host.
$ telnet localhost 11212
Trying ::1...
Connected to localhost.
Escape character is '^]'.
delete age
DELETED
quit
Connection closed by foreign host.
$ telnet localhost 11211
Trying ::1...
Connected to localhost.
Escape character is '^]'.
get age #删除也是同步的
END
4.总结

简单配置几下就可以实现memcached的备份,是不是很开森?!考虑下面的一些情况:

repcached只支持memcached1.2.x,好几年没更新过了 当有一台memcache宕机,repcached不会自动帮你切换到另外一台,要手动切换,考虑用缓存代理+主从复制