教你使用MySQL触发器自动更新memcache

mysql 5.1支持触发器以及自定义函数接口(UDF)的特性，如果配合libmemcache以及Memcached Functions for MySQL，就能够实现memcache的自动更新。简单记录一下安装测试步骤。

安装步骤

安装memcached,这个步骤很简单，随处可见

安装mysql server 5.1RC，安装办法也很大众，不废话了

编译libmemcached，解压后安装即可./configure; make; make install

编译Memcached Functions for MySQL，在找一个最新的版本下载就是，./configure --with-mysql=/usr/local/mysql/bin/mysql_config --libdir=/usr/local/mysql/lib/mysql/

make

make install

接下来有两个办法让Memcached Functions for MySQL在mysql中生效

在mysql的shell中执行memcached_functions_mysql源码目录下的sql/install_functions.sql，这会把memcache function作为UDF加入mysql

运行memcached_functions_mysql源码目录下的utils/install.pl，这是一个perl脚本，作用同上一条

测试memcache function

以下测试脚本摘自memcached_functions_mysql的源码目录，有兴趣可以试试

PLAIN TEXTCODE: drop table if exists urls;

create table urls (

id int(3) not null,

url varchar(64) not null default ,

primary key (id)

);

select memc_servers_set(localhost:11211);

select memc_set(urls:sequence, 0);

DELIMITER |

DROP TRIGGER IF EXISTS url_mem_insert;

CREATE TRIGGER url_mem_insert

BEFORE INSERT ON urls

FOR EACH ROW BEGIN

SET NEW.id= memc_increment(urls:sequence);

SET @mm= memc_set(concat(urls:,NEW.id), NEW.url);

END |

DELIMITER ;

insert into urls (url) values (http://google.com);

insert into urls (url) values (http://www.ooso.net/index.php);

insert into urls (url) values (http://www.devdao.net/);

insert into urls (url) values (http://slashdot.org);

insert into urls (url) values (http://mysql.com);

select * from urls;

select memc_get(urls:1);

select memc_get(urls:2);

select memc_get(urls:3);

select memc_get(urls:4);

select memc_get(urls:5);