memcached单点

mac2022-06-30 43

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

·········10········20········30········40········50········60········ 1. #wget http://downloads.sourceforge.net/repcached/memcached-1.2.8-repcached-2.2.tar.gz 2. #tar zxf memcached-1.2.8-repcached-2.2.tar.gz 3. #cd memcached-1.2.8-repcached-2.2

方式二、下载对应patch版本

·········10········20········30········40········50········60········ 1. #wget http://downloads.sourceforge.net/repcached/repcached-2.2-1.2.8.patch.gz 2. #gzip -cd ../repcached-2.2-1.2.8.patch.gz | patch -p1】 3. #./configure –enable-replication 4. # make 5. # make install

3、启动：

启动master

·········10········20········30········40········50········60········ 1. # ./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） 2. replication: connect (peer=127.0.0.1:11111) 3. replication: accept 4. replication: marugoto copying 5. replication: start

启动salve

·········10········20········30········40········50········60········ 1. # ./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） 2. replication: connect (peer=127.0.0.1:11111) 3. replication: marugoto copying 4. replication: close 5. replication: listen

4、测试：

操作master

·········10········20········30········40········50········60········ 01. [root@localhost bin]# telnet 127.1 11211 02. Trying 127.0.0.1... 03. Connected to localhost.localdomain (127.0.0.1)... 04. Escape character is '^]'. 05. get key1 06. END 07. set key1 0 0 2 08. aa 09. STORED 10. quit 11. Connection closed by foreign host.

查看slave

·········10········20········30········40········50········60········ 01. [root@localhost bin]# telnet 127.1 11212 02. Trying 127.0.0.1... 03. Connected to localhost.localdomain (127.0.0.1)... 04. Escape character is '^]'. 05. get key1 06. VALUE key1 0 2 07. aa 08. END 09. quit 10. 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：

·········10········20········30········40········50········60········ 1. wget http://monkey.org/~provos/libevent-1.4.9-stable.tar.gz 2. tar zxvf libevent-1.4.9-stable.tar.gz 3. cd libevent-1.4.9-stable/ 4. ./configure --prefix=/usr 5. make && make install 6. cd ../

b、编译安装Memcached：

·········10········20········30········40········50········60········ 1. wget http://danga.com/memcached/dist/memcached-1.2.6.tar.gz 2. tar zxvf memcached-1.2.6.tar.gz 3. cd memcached-1.2.6/ 4. ./configure --with-libevent=/usr 5. make && make install 6. cd ../

c、编译安装magent：

·········10········20········30········40········50········60········ 01. mkdir magent 02. cd magent/ 03. wget http://memagent.googlecode.com/files/magent-0.5.tar.gz 04. tar zxvf magent-0.5.tar.gz 05. /sbin/ldconfig 06. sed -i "s#LIBS = -levent#LIBS = -levent -lm#g" Makefile 07. make 08. cp magent /usr/bin/magent 09. cd ../

2、使用实例：

·········10········20········30········40········50········60········ 1. memcached -m 1 -u root -d -l 127.0.0.1 -p 11211 2. memcached -m 1 -u root -d -l 127.0.0.1 -p 11212 3. memcached -m 1 -u root -d -l 127.0.0.1 -p 11213 4. 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：

·········10········20········30········40········50········60········ 01. [root@centos52 ~]# telnet 127.0.0.1 12000 02. Trying 127.0.0.1... 03. Connected to 127.0.0.1. 04. Escape character is '^]'. 05. stats 06. memcached agent v0.4 07. matrix 1 -> 127.0.0.1:11211, pool size 0 08. matrix 2 -> 127.0.0.1:11212, pool size 0 09. END 10. set key1 0 0 8 11. zhangyan 12. STORED 13. set key2 0 0 8 14. zhangyan 15. STORED 16. quit 17. Connection closed by foreign host. 18. 19. [root@centos52 ~]# telnet 127.0.0.1 11211 20. Trying 127.0.0.1... 21. Connected to 127.0.0.1. 22. Escape character is '^]'. 23. get key1 24. END 25. get key2 26. VALUE key2 0 8 27. zhangyan 28. END 29. quit 30. Connection closed by foreign host. 31. 32. [root@centos52 ~]# telnet 127.0.0.1 11212 33. Trying 127.0.0.1... 34. Connected to 127.0.0.1. 35. Escape character is '^]'. 36. get key1 37. VALUE key1 0 8 38. zhangyan 39. END 40. get key2 41. END 42. quit 43. Connection closed by foreign host. 44. 45. [root@centos52 ~]# telnet 127.0.0.1 11213 46. Trying 127.0.0.1... 47. Connected to 127.0.0.1. 48. Escape character is '^]'. 49. get key1 50. VALUE key1 0 8 51. zhangyan 52. END 53. get key2 54. VALUE key2 0 8 55. zhangyan 56. END 57. quit 58. Connection closed by foreign host.

模拟11211、11212端口的Memcached死掉

·········10········20········30········40········50········60········ 01. [root@centos52 ~]# ps -ef | grep memcached 02. root 6589 1 0 01:25 ? 00:00:00 memcached -m 1 -u root -d -l 127.0.0.1 -p 11211 03. root 6591 1 0 01:25 ? 00:00:00 memcached -m 1 -u root -d -l 127.0.0.1 -p 11212 04. root 6593 1 0 01:25 ? 00:00:00 memcached -m 1 -u root -d -l 127.0.0.1 -p 11213 05. root 6609 6509 0 01:44 pts/0 00:00:00 grep memcached 06. [root@centos52 ~]# kill -9 6589 07. [root@centos52 ~]# kill -9 6591 08. [root@centos52 ~]# telnet 127.0.0.1 12000 09. Trying 127.0.0.1... 10. Connected to 127.0.0.1. 11. Escape character is '^]'. 12. get key1 13. VALUE key1 0 8 14. zhangyan 15. END 16. get key2 17. VALUE key2 0 8 18. zhangyan 19. END 20. quit 21. Connection closed by foreign host.

模拟11211、11212端口的Memcached重启复活

·········10········20········30········40········50········60········ 01. [root@centos52 ~]# memcached -m 1 -u root -d -l 127.0.0.1 -p 11211 02. [root@centos52 ~]# memcached -m 1 -u root -d -l 127.0.0.1 -p 11212 03. [root@centos52 ~]# telnet 127.0.0.1 12000 04. Trying 127.0.0.1... 05. Connected to 127.0.0.1. 06. Escape character is '^]'. 07. get key1 08. END 09. get key2 10. END 11. quit 12. 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。

转载于:https://www.cnblogs.com/sunwubin/p/3548943.html

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