一.Repcached (memcached同步补丁)
下载地址:http://sourceforge.net/projects/repcached/files/repcached/2.2.1-1.2.8/
版本号:memcached 1.2.8 repcached 2.2.1
1、repcached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
2、安装
在两台服务器上分别安装memcached服务,另注本文libevent的版本为:libevent-1.4.13,下载地址: http://www.monkey.org/~provos/libevent-1.4.13-stable.tar.gz (安装省略)
repcached有两种方式:
方式一、下载对应的repcached版本
#wget http://downloads.sourceforge.net/repcached/memcached-1.2.8-repcached-2.2.tar.gz #tar zxf memcached-1.2.8-repcached-2.2.tar.gz #cd memcached-1.2.8-repcached-2.2
方式二、下载对应patch版本
#wget http://downloads.sourceforge.net/repcached/repcached-2.2-1.2.8.patch.gz #gzip -cd ../repcached-2.2-1.2.8.patch.gz | patch -p1】 #./configure –enable-replication # make # make install
3、启动:
启动master
# ./memcached -v -u root -d -l 127.0.0.1 -p 11211 -x 127.0.0.1 -X 11111 (11211:master端口;11111:同步端口) replication: connect (peer=127.0.0.1:11111) replication: accept replication: marugoto copying replication: start
启动salve
# ./memcached -v -u root -d -l 127.0.0.1 -p 11212 -x 127.0.0.1 -X 11111 (11212:slave端口;11111:同步端口) replication: connect (peer=127.0.0.1:11111) replication: marugoto copying replication: close replication: listen
4、测试:
操作master
[root@localhost bin]# telnet 127.1 11211 Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1)... Escape character is '^]'. get key1 END set key1 0 0 2 aa STORED quit Connection closed by foreign host.
查看slave
[root@localhost bin]# telnet 127.1 11212 Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1)... Escape character is '^]'. get key1 VALUE key1 0 2 aa END quit Connection closed by foreign host.
注意:如果master down机,slave接管并成为master,这时down机的master只能启用slave,他们之间互换角色,才能保持复制功能。换句话说,master没有抢占功能。而且,同步间隔时间未知。
优点:
- 数据冗余
- 两台memcached都可以进行读写操作
缺点:
- 只支持单对单
- 只支持memcached 1.2.x版本
二.Magent (memcached的代理)
原文地址:http://blog.s135.com/post/393/
magent是一款开源的Memcached代理服务器软件,其项目网址为:
http://code.google.com/p/memagent/
1、安装步骤:
a、编译安装libevent:
wget http://monkey.org/~provos/libevent-1.4.9-stable.tar.gz tar zxvf libevent-1.4.9-stable.tar.gz cd libevent-1.4.9-stable/ ./configure --prefix=/usr make && make install cd ../
b、编译安装Memcached:
wget http://danga.com/memcached/dist/memcached-1.2.6.tar.gz tar zxvf memcached-1.2.6.tar.gz cd memcached-1.2.6/ ./configure --with-libevent=/usr make && make install cd ../
c、编译安装magent:
mkdir magent cd magent/ wget http://memagent.googlecode.com/files/magent-0.5.tar.gz tar zxvf magent-0.5.tar.gz /sbin/ldconfig sed -i "s#LIBS = -levent#LIBS = -levent -lm#g" Makefile make cp magent /usr/bin/magent cd ../
2、使用实例:
memcached -m 1 -u root -d -l 127.0.0.1 -p 11211 memcached -m 1 -u root -d -l 127.0.0.1 -p 11212 memcached -m 1 -u root -d -l 127.0.0.1 -p 11213 magent -u root -n 51200 -l 127.0.0.1 -p 12000 -s 127.0.0.1:11211 -s 127.0.0.1:11212 -b 127.0.0.1:11213
- 分别在11211、11212、11213端口启动3个Memcached进程,在12000端口开启magent代理程序;
- 11211、11212端口为主Memcached,11213端口为备份Memcached;
- 连接上12000的magent,set key1和set key2,根据哈希算法,key1被写入11212和11213端口的Memcached,key2被写入11212和11213端口的Memcached;
- 当11211、11212端口的Memcached死掉,连接到12000端口的magent取数据,数据会从11213端口的Memcached取出;
- 当11211、11212端口的Memcached重启复活,连接到12000端口,magent会从11211或11212端口的Memcached取数据,由于这两台Memcached重启后无数据,因此magent取得的将是空值,尽管11213端口的Memcached还有数据(此问题尚待改进)。
3、整个测试流程:
[root@centos52 ~]# telnet 127.0.0.1 12000 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. stats memcached agent v0.4 matrix 1 -> 127.0.0.1:11211, pool size 0 matrix 2 -> 127.0.0.1:11212, pool size 0 END set key1 0 0 8 zhangyan STORED set key2 0 0 8 zhangyan STORED quit Connection closed by foreign host. [root@centos52 ~]# telnet 127.0.0.1 11211 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. get key1 END get key2 VALUE key2 0 8 zhangyan END quit Connection closed by foreign host. [root@centos52 ~]# telnet 127.0.0.1 11212 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. get key1 VALUE key1 0 8 zhangyan END get key2 END quit Connection closed by foreign host. [root@centos52 ~]# telnet 127.0.0.1 11213 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. get key1 VALUE key1 0 8 zhangyan END get key2 VALUE key2 0 8 zhangyan END quit Connection closed by foreign host.
模拟11211、11212端口的Memcached死掉
[root@centos52 ~]# ps -ef | grep memcached root 6589 1 0 01:25 ? 00:00:00 memcached -m 1 -u root -d -l 127.0.0.1 -p 11211 root 6591 1 0 01:25 ? 00:00:00 memcached -m 1 -u root -d -l 127.0.0.1 -p 11212 root 6593 1 0 01:25 ? 00:00:00 memcached -m 1 -u root -d -l 127.0.0.1 -p 11213 root 6609 6509 0 01:44 pts/0 00:00:00 grep memcached [root@centos52 ~]# kill -9 6589 [root@centos52 ~]# kill -9 6591 [root@centos52 ~]# telnet 127.0.0.1 12000 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. get key1 VALUE key1 0 8 zhangyan END get key2 VALUE key2 0 8 zhangyan END quit Connection closed by foreign host.
模拟11211、11212端口的Memcached重启复活
[root@centos52 ~]# memcached -m 1 -u root -d -l 127.0.0.1 -p 11211 [root@centos52 ~]# memcached -m 1 -u root -d -l 127.0.0.1 -p 11212 [root@centos52 ~]# telnet 127.0.0.1 12000 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. get key1 END get key2 END quit Connection closed by foreign host.
优点:
- 可以做多主或多从
缺点:
- 当master宕掉又恢复后,取不到数据。
三.Repcached和Magent结合
安装memcached 1.2.8、repcached 2.2.1、magent 0.5
测试流程:
1、启动memcached和magent
开启代理,代理端口为12000,设置127.0.0.1:11211为主,127.0.0.1:11212为从。
magent -u root -p 12000 -s 127.0.0.1:11211 -b 127.0.0.1:11212
启动两个memcached进程,做数据同步,同步端口为11111。
./memcached -u root -d -l 127.0.0.1 -p 11211 -x 127.0.0.1 -X 11111
./memcached -u root -d -l 127.0.0.1 -p 11212 -x 127.0.0.1 -X 11111
2、从代理写入数据,在两台memcached上查看
[root@localhost bin]# telnet 127.1 12000 Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1). Escape character is '^]'. set key1 0 0 1 a STORED quit Connection closed by foreign host. [root@localhost bin]# telnet 127.1 11211 Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1). Escape character is '^]'. get key1 VALUE key1 0 1 a END quit Connection closed by foreign host.
3. 模拟主或从memcached宕机后,数据是否存在
[root@localhost bin]# ps aux|grep memcached root 15314 0.0 0.4 3556 2108 ? Ss 16:03 0:00 ./memcached -u root -d -l 127.0.0.1 -p 11211 -x 127.0.0.1 -X 11111 root 15318 0.0 0.3 3556 1836 ? Ss 16:04 0:00 ./memcached -u root -d -l 127.0.0.1 -p 11211 -x 127.0.0.1 -X 11111 root 15370 0.0 0.1 4016 696 pts/3 R+ 16:09 0:00 grep memcached [root@localhost bin]# kill 15314 [root@localhost bin]# ps aux|grep memcached root 15318 0.0 0.3 3556 1836 ? Ss 16:04 0:00 ./memcached -u root -d -l 127.0.0.1 -p 11211 -x 127.0.0.1 -X 11111 root 15370 0.0 0.1 4016 696 pts/3 R+ 16:09 0:00 grep memcached [root@localhost bin]# telnet 127.1 12000 Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1). Escape character is '^]'. set key1 0 0 1 a STORED quit Connection closed by foreign host. [root@localhost bin]# telnet 127.1 11212 Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1). Escape character is '^]'. get key1 VALUE key1 0 1 a END quit Connection closed by foreign host.
4. 模拟主或从memcached恢复后,数据是否存在/同步
[root@localhost bin]# ./memcached -u root -d -l 127.0.0.1 -X 11111 [root@localhost bin]# ps aux|grep memcached root 15318 0.0 0.4 3556 2112 ? Ss 16:04 0:00 ./memcached -u root -d -l 127.0.0.1 -p 11211 -x 127.0.0.1 -X 11111 root 15380 0.0 0.3 3556 1808 ? Ss 16:11 0:00 ./memcached -u root -d -l 127.0.0.1 -p 11211 -x 127.0.0.1 -X 11111 root 15384 0.0 0.1 4016 700 pts/3 R+ 16:11 0:00 grep memcached [root@localhost bin]# telnet 127.1 12000 Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1). Escape character is '^]'. set key1 0 0 1 a STORED quit Connection closed by foreign host. [root@localhost bin]# telnet 127.1 11211 Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1). Escape character is '^]'. get key1 VALUE key1 0 1 a END quit Connection closed by foreign host.
优点:
- 数据冗余
- 两台memcached都可进行读写操作
- 可以做多主或多从(未测试)
缺点:
- 只支持memcached 1.2.x版本
原文发布时间为:2012-07-05
本文来自合作伙伴“Linux中国”