memcached初体验

最新推荐文章于 2024-07-24 22:54:08 发布

caiqiiqi

最新推荐文章于 2024-07-24 22:54:08 发布

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分类专栏：网络编程

本文链接：https://blog.youkuaiyun.com/caiqiiqi/article/details/79149652

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直接安装

```

sudo apt install memcached

```

然后就会默认在后台运行。

```

$ ps aux|grep memcached
memcache 87827 0.0 0.3 326560 3796 ? Ssl 17:48 0:00 /usr/bin/memcached -m 64 -p 11211 -u memcache -l 127.0.0.1

```

来一个PHP的demo(需要安装sudo apt install php-memcached)。

```

<?php
# 先建立到本地memcached的连接。

$mem = new Memcached();
$mem->addServer("127.0.0.1", 11211);
# 然后尝试读取某key的值（因为没有设置，所以这个值还没有）

$key1 = "cqq";
$result = $mem->get($key1);

# 第一次判断这个值发现没有之后，会通过->add()函数将值加到memcached，第二次就会有了。
if ($result){
echo $result;
}else {
echo "[!] no matching key found! I'm gonna add that now.";
$mem->add($key1, "caiqiqi") or die("[!] couldn't save any values to memcached!");
}
?>

```

然后想要命令行访问，直接连接他的TCP端口，然后

```

$ nc -v 127.0.0.1 11211
Connection to 127.0.0.1 11211 port [tcp/*] succeeded!
get cqq
VALUE cqq 0 7
caiqiqi
END

```

## 用memcached缓存mysql查询到的数据

### php demo

```

<?php
$mem = new Memcached();
$mem->addServer("127.0.0.1", 11211);

# 准备工作：先创建数据库，账户，密码

# mysql> create database mem_test;

# mysql> grant all on mem_test.* to test@'localhost' identified by 'testing123';

# mysql> use mem_test;

# mysql> create table sample_data(id int, name varchar(30));

# mysql> insert into sample_data values(1, "some_data");
$servername = "127.0.0.1";
$username = "test";
$password = "testing123";
$dbname = "mem_test";

$conn = new mysqli($servername, $username, $password, $dbname) or dir(mysql_error());
$query_str = "select id from sample_data where name = 'some_data'";
$query_key = "KEY" . md5($query_str); # 通过加上md5值生成一个唯一的key
print $query_key;

$result = $mem->get($query_key);
if ($result){
print " Data was: ". $result[0] . "";
print " Caching success!Retrived data from memcached!";
} else{
$result = $conn->query($query_str) or dir(mysql_error());
$row = $result->fetch_assoc();
#var_dump($row);
$mem->set($query_key, $row['id'], 100); # 过期时间s
print "Data not found in memcached.Data retrieved from MySQL and stored in memcached for next time.";
}

```

执行完上述php代码之后（命令行或者WEB），再去memcached里去查找。

```

caikiki@ubuntu:~$ nc -v 127.0.0.1 11211
Connection to 127.0.0.1 11211 port [tcp/*] succeeded!
get KEYc029fe1cf78a2428b554004188ab9468
VALUE KEYc029fe1cf78a2428b554004188ab9468 0 1
1
END

```

参考：

http://www.runoob.com/memcached/memcached-connection.html

https://www.digitalocean.com/community/tutorials/how-to-install-and-use-memcache-on-ubuntu-14-04