With the development of Internet technology and the explosive increase in visits, how to improve the performance of the website has become an urgent issue. Caching technology is one of the most commonly used solutions to improve website performance. As a very popular back-end development language, PHP also provides many caching technologies, the most commonly used of which is Memcache caching technology.
Memcache is a high-performance distributed memory object caching system, which is often used to improve data access speed and reduce database load. This article will introduce how to use Memcache caching technology in PHP to improve data reading performance.
1. Memcache installation and configuration
Memcache extension can be obtained in PECL. Use the following commands to download and install the Memcache extension.
$ pecl install memcache
Add the following lines to the php.ini file to enable the Memcache extension.
extension=memcache.so
On the Linux server, use the following command to start the Memcached service.
$ memcached -d -m 64 -u root -l 127.0.0.1 -p 11211
You can use the following code Snippet tests whether Memcache is available.
$memcache = new Memcache;
$memcache->connect('localhost', 11211) or die ("Could not connect");
2. Use Memcache to cache data
Storing data into Memcache is very simple. Use the following code to store data key-value pairs into the cache.
$memcache = new Memcache;
$memcache->connect('localhost', 11211) or die ("Could not connect");
$memcache->set('key ', 'value', 0, 3600);
The above code saves "key" and "value" to Memcache, and the cache time is 3600 seconds.
When you need to get the data in the Memcache cache, you can use the following code.
$memcache = new Memcache;
$memcache->connect('localhost', 11211) or die ("Could not connect");
$data = $memcache->get ('key');
The above code will get the value with the key "key" from Memcache.
If you need to delete the data cached in Memcache, you can use the following code snippet.
$memcache = new Memcache;
$memcache->connect('localhost', 11211) or die ("Could not connect");
$memcache->delete('key ');
The above code will delete the data with the key "key" from Memcache.
3. Use Memcache to accelerate database access
When using Memcache to improve data reading performance, the most common application scenario is to cache data in the database. If certain data of a website is frequently read from the database, using Memcache to cache this data can reduce the load on the database server and improve the performance of the website.
The following are the steps to use Memcache to speed up database access.
When requesting data for the first time, get the data from the database and store it in Memcache.
$memcache = new Memcache;
$memcache->connect('localhost', 11211) or die ("Could not connect");
$data = $memcache- >get('key');
if (!$data) { //The data does not exist in Memcache
$db = new mysqli('localhost', 'user', 'password', 'database'); $result = $db->query('SELECT * FROM table'); $data = $result->fetch_all(MYSQLI_ASSOC); $db->close(); $memcache->set('key', $data, 0, 3600);
}
In subsequent requests, call Memcache cached data to avoid database queries.
$memcache = new Memcache;
$memcache->connect('localhost', 11211) or die ("Could not connect");
$data = $memcache- >get('key');
if ($data === false) { //The data does not exist in Memcache and needs to be read from the database
$db = new mysqli('localhost', 'user', 'password', 'database'); $result = $db->query('SELECT * FROM table'); $data = $result->fetch_all(MYSQLI_ASSOC); $db->close(); $memcache->set('key', $data, 0, 3600);
}
Using the above code, the data can be read from the database. After caching through Memcache, the cache can be accessed to obtain the data in subsequent requests, thereby improving data reading performance.
4. Summary
This article introduces how to use Memcache caching technology in PHP to improve data reading performance. By caching data in memory and avoiding frequent access to the database, the load on the database can be reduced and the performance of the website can be improved. Of course, Memcache caching technology is not perfect, but in actual applications, Memcache is still an efficient and reliable caching solution.
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