cache初学之四 magent代理安装与测试

程序员文章站 2022-07-08 23:45:49

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今天对magent进行代理测试

memagent（http://code.google.com/p/memagent/）是一个memcache proxy，它提供的功能及特点有：

1、和每个memcache server保持多个长连接，效果是减少memcache server保持的连接数量及创建销毁连接的开销。不过，memcache本身就支持大并发连接，这个功能也就没什么特别的说道。

2、支持memcache的binary协议命令，实现请求的转发。

3、和memcache一样，基于libevent的事件驱动来处理IO。

4、支持ketama 的一致性hash算法。

5、支持memcache backup集群，当memcache集群有机器挂了，memagent会将get请求转向memcache backup集群。这个功能对于cache的稳定性要求高的场景下会有用武之地。

就提供的功能而言，memagent是个很简单的东西。对于较大的memcache集群，可以考虑搭一套memagent作为proxy使用。

Magent 代理的安装

安装magent到/usr/local/下
cd /usr/local
mkdir magent

解压

[root@localhost tmp]# cd /usr/local/magent

[root@localhost magent]# ls

magent-0.6.tar.gz

[root@localhost magent]# tar zxvf magent-0.6.tar.gz

ketama.c

ketama.h

magent.c

Makefile

安装

[root@localhost magent]# /sbin/ldconfig

[root@localhost magent]# sed -i "s#LIBS = -levent#LIBS = -levent -lm#g" Makefile

[root@localhost magent]# make

gcc -Wall -g -O2 -I/usr/local/include -c -o magent.o magent.c

gcc -Wall -g -O2 -I/usr/local/include -c -o ketama.o ketama.c

gcc -Wall -g -O2 -I/usr/local/include -o magent magent.o ketama.o -levent -lm -lm -L/usr/local/lib

配置memcached的服务

[root@localhost /]# memcached -m 1 -u root -d -l 192.168.1.118 -p 11212

[root@localhost /]# memcached -m 1 -u root -d -l 192.168.1.118 -p 11213

[root@localhost /]# memcached -m 1 -u root -d -l 192.168.1.118 -p 11214

启动memagent服务

[root@localhost magent]# ./magent -u root -n 4096 -l 192.168.1.118 -p 12000 -s 192.168.1.118:11212 -s 192.168.1.118:11213 -b 192.168.1.118:11214

Magent 的命令参数

-h this message
  -u uid
  -g gid
  -p port, default is 11211. (0 to disable tcp support)
  -s ip:port, set memcached server ip and port
  -b ip:port, set backup memcached server ip and port
  -l ip, local bind ip address, default is 0.0.0.0
  -n number, set max connections, default is 4096
  -D don't go to background
  -k use ketama key allocation algorithm
  -f file, unix socket path to listen on. default is off
  -i number, max keep alive connections for one memcached server, default is 20
  -v verbose

1、分别在11212、11213、11214端口启动3个Memcached进程，在12000端口开启magent代理程序；

2、 11212、11213端口为主Memcached，11214端口为备份Memcached；

3、连接上12000的magent，set key1和set key2，根据哈希算法，key1被写入11213和11214端口的Memcached，key2被写入11213和11214端口的Memcached；

4、当11212、11213端口的Memcached死掉，连接到12000端口的magent取数据，数据会从11214端口的Memcached取出；

5、当11212、11213端口的Memcached重启复活，连接到12000端口，magent会从11212或11213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11214端口的Memcached还有数据（此问题尚待改进）。

整个测试流程

[root@localhost ~]# telnet 192.168.1.118 12000

Trying 192.168.1.118...

Connected to 192.168.1.118 (192.168.1.118).

Escape character is '^]'.

stats

memcached agent v0.6

matrix 1 -> 192.168.1.118:11212, pool size 0

matrix 2 -> 192.168.1.118:11213, pool size 1

END

set key1 0 0 5

hello

STORED

set key2 0 0 5

world

STORED

quit

Connection closed by foreign host.

[root@localhost ~]# telnet 192.168.1.118 11212

Trying 192.168.1.118...

Connected to 192.168.1.118 (192.168.1.118).

Escape character is '^]'.

get key1

END

get key2

VALUE key2 0 5

world

END

quit

Connection closed by foreign host.

[root@localhost ~]# telnet 192.168.1.118 11213

Trying 192.168.1.118...

Connected to 192.168.1.118 (192.168.1.118).

Escape character is '^]'.

get key1

VALUE key1 0 5

hello

END

get key2

END

quit

Connection closed by foreign host.

[root@localhost ~]# telnet 192.168.1.118 11214

Trying 192.168.1.118...

Connected to 192.168.1.118 (192.168.1.118).

Escape character is '^]'.

get key1

VALUE key1 0 5

hello

END

get key2

VALUE key2 0 5

world

END

quit

Connection closed by foreign host.

模拟11212、11213端口的memcache死掉

[root@localhost ~]# ps -ef | grep memcached

root 5126 1 0 19:14 ? 00:00:00 memcached -m 1 -u root -d -l 192.168.1.118 -p 11212

root 5134 1 0 19:14 ? 00:00:00 memcached -m 1 -u root -d -l 192.168.1.118 -p 11213

root 5142 1 0 19:14 ? 00:00:00 memcached -m 1 -u root -d -l 192.168.1.118 -p 11214

root 5976 5526 0 20:11 pts/1 00:00:00 grep memcached

[root@localhost ~]# kill -9 5126

[root@localhost ~]# kill -9 5134

[root@localhost ~]# telnet 192.168.1.118 12000

Trying 192.168.1.118...

Connected to 192.168.1.118 (192.168.1.118).

Escape character is '^]'.

get key1

VALUE key1 0 5

hello

END

get key2

VALUE key2 0 5

world

END

quit

Connection closed by foreign host.

模拟11212、11213端口的memcache重启复活

[root@localhost ~]# memcached -m 1 -u root -d -l 192.168.1.118 -p 11212

[root@localhost ~]# memcached -m 1 -u root -d -l 192.168.1.118 -p 11213

[root@localhost ~]# telnet 192.168.1.118 12000

Trying 192.168.1.118...

Connected to 192.168.1.118 (192.168.1.118).

Escape character is '^]'.

get key1

END

get key2

END

quit

Connection closed by foreign host.