memcached的安装、常用命令以及在实际开发中的案例(2)

方式2：编译安装

# 安装依赖
yum -y install zlib-devel
yum -y install libmemcached-devel

# 编译安装
wget https:pecl.php.net/get/memcached-3.1.4.tgz 
tar zxvf memcached-3.1..tgz

cd memcached-4 
/usr/bin/phpize

./configure --with-php-config=/usr/bin/php-config 
 make && make install

# 修改php.ini
vim /etc/php.ini

# 添加
extension=memcached.so"

# 保存退出

# 重启httpd服务
service httpd restart

# 临时关闭
selinux
setenforce 

# 永久关闭
selinux
vim /etc/selinux/config

# 修改
selinux
selinux=disabled

# 保存退出

PHP案例：构建高速缓存
- 如果缓存数据存在，请求memcached服务，查询缓存数据，显示给用户
- 如果缓存数据不存在，请求数据源数据，将数据存储至缓存中
第一次从数据库获取?

进入mysql 
mysql -uroot -p

创建数据库
create database cms;
use cms;

创建数据表
create table cms_users(
id int unsigned not null auto_increment primary key,username varchar(50) not null default '',age tinyint unsigned not 100) not default CURRENT_TIMESTAMP
)engine=innodb default charset=utf8;

插入数据
insert into cms_users(username,age,sex,major) values(cyy',22,1)">1,1)">math);
insert into cms_users(username,1)">cyy22,1)">chinesecyy323,1)">3,1)">englishcyy424,1)">4,1)">businesscyy525,1)">5,1)">php);

查看数据
select * from cms_users;

users.php

<?php
$start = microtime(true);

# 建立memcached连接
$mem = new Memcached();
$mem->addServer('127.0.0.1',11211);
$key_name = 'users';
$expire_time = 60;过期时间

 判断用户数据在缓存当中是否存在，如果存在，直接get，显示给用户
# 如果不存在，查询数据库，将数据写入到memcached当中，显示给用户

if (false === ($users = $mem->get($key_name))) {
     数据不存在于缓存当中，调用PDO查询DB
    $users = fetchDataFromDB();
     将查询出的数据写入到memcached当中
    $mem->set($key_name,1)">$users,time() + $expire_time);
}

function fetchDataFromDB() {
    echo 'Fetching data from db....';
     Fetch users from mysql using PDO
    try {
        $dsn = "mysql:dbname=cms;host=localhost;port=3306";
        $pdo = new PDO($dsn,'root','123456',1)"> 
                [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
        $sql = 'select * from cms_users'$stmt = $pdo->prepare($sql);
        $stmt->execute();
        $stmt->fetchAll(PDO::FETCH_ASSOC);
    } catch (PDOException $pe) {
        echo $pe->getMessage();
    }
    return $users;
}

$sex_array = ['unknown','male','female'];
echo '<table border=1>';
echo '<tr><th>ID</th><th>USERNAME</th><th>AGE</th><th>SEX</th><th>MAJOR</th><th>CREATED_TIME</th></tr>'foreach ($users as $user) {
    echo '<tr>'echo '<td>'.$user['id'].'</td>'$user['username'].'</td>'$user['age'].'</td>'$sex_array[$user['sex']].'</td>'$user['major'].'</td>'$user['created_time'].'</td>'echo '</tr>';
}
echo '</table>'$end = );
echo "Running time: ". ($end-$start);

小案例

<?php

 Memcached();

 telnet 127.0.0.1 11211
 stats
$stats = $mem->getStats();
 var_dump($stats);
$mem->set('php_client',['one' => 1,'two' => 2],1)">time() + 60$res = $mem->get('php_client'var_dump($res);

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