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http://download.tangent.org/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');