search
HomeBackend DevelopmentPHP TutorialAnalysis on how to use long connection of PHP extension module memcached, extension module memcached_PHP tutorial

Analysis on how to use long connection of PHP extension module memcached, extension module memcached

There is an article widely circulated on the Internet about the difference between memcache and memcached, the two extension modules of PHP. It specifically emphasizes that a big difference between memcached and memcached is that the memcached module does not support long connections. So for many years I thought that memcached did not support long connections. In fact, this is not the case. The memcached extension module has supported long connections since a very early version. We can see from the source code of the extension module:

/* {{{ Memcached::__construct([string persistent_id[, callback on_new[, string connection_str]]]))

Creates a Memcached object, optionally using persistent memcache connection */

static PHP_METHOD(Memcached, __construct)

{

From the PHP manual, we can see that the constructor provided by the memcached extension module provides an optional parameter persistent_id, which is introduced in the manual:

By default, Memcached instances will be destroyed after the request ends. However, you can share instances between requests by specifying a unique ID for each instance by persistent_id when creating it. All instances created with the same persistent_id value share the same connection.

The meaning of this parameter is that if you pass a named id to the constructor, then a long connection will be established. Usually we use PHP-FPM mode, so that the PHP-FPM process will resume the memcached service A long connection channel. We can also understand that persistent_id is a connection pool name, and all php-fpm processes are members of this connection pool.

But what we need to pay attention to is that PHP is an interpreted language. When PHP establishes a long connection through the memached module for the first time, remember that subsequent PHP executions should not build long connections named with the same persistent_id through the constructor of memcached. Long connections with different persistent_id names can be established. If the same name is executed repeatedly by PHP, it will definitely cause the php-fpm process to be abnormal and cause the communication with memcached to become slower and slower. At the same time, depending on the version of libmemcached, it will also cause PHP to generate coredump. .

So how do we prevent a single php-fpm from repeatedly establishing a long connection after establishing a long connection named with persistent_id? In fact, it is explained in the PHP manual with comments, and the content is as follows:

When using persistent connections, it is important to not re-add servers.

This is what you do not want to do:

$mc = new Memcached('mc');
$mc->setOption(Memcached::OPT_LIBKETAMA_COMPATIBLE, true);
$mc->addServers(array(
  array('mc1.example.com',11211),
  array('mc2.example.com',11211),
));


Every time the page is loaded those servers will be appended to the list resulting in many simultaneous open connections to the same server. The addServer/addServers functions to not check for existing references to the specified servers.

A better approach is something like:

$mc = new Memcached('mc');
$mc->setOption(Memcached::OPT_LIBKETAMA_COMPATIBLE, true);
if (!count($mc->getServerList())) {
  $mc->addServers(array(
    array('mc1.example.com',11211),
    array('mc2.example.com',11211),
  ));
}<br />

Use the getServerList() method to check whether a long connection resource with the same name already exists in the php-fpm process container currently used for execution. If it exists, do not repeatedly use the addServers() method to add a new connection configuration.

www.bkjia.comtruehttp: //www.bkjia.com/PHPjc/932496.htmlTechArticleAnalysis on how to use long connection of PHP extension module memcached, extension module memcached There is an article widely circulated on the Internet about PHP The difference between the two extension modules memcache and memcached, especially...
Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
PHP: An Introduction to the Server-Side Scripting LanguagePHP: An Introduction to the Server-Side Scripting LanguageApr 16, 2025 am 12:18 AM

PHP is a server-side scripting language used for dynamic web development and server-side applications. 1.PHP is an interpreted language that does not require compilation and is suitable for rapid development. 2. PHP code is embedded in HTML, making it easy to develop web pages. 3. PHP processes server-side logic, generates HTML output, and supports user interaction and data processing. 4. PHP can interact with the database, process form submission, and execute server-side tasks.

PHP and the Web: Exploring its Long-Term ImpactPHP and the Web: Exploring its Long-Term ImpactApr 16, 2025 am 12:17 AM

PHP has shaped the network over the past few decades and will continue to play an important role in web development. 1) PHP originated in 1994 and has become the first choice for developers due to its ease of use and seamless integration with MySQL. 2) Its core functions include generating dynamic content and integrating with the database, allowing the website to be updated in real time and displayed in personalized manner. 3) The wide application and ecosystem of PHP have driven its long-term impact, but it also faces version updates and security challenges. 4) Performance improvements in recent years, such as the release of PHP7, enable it to compete with modern languages. 5) In the future, PHP needs to deal with new challenges such as containerization and microservices, but its flexibility and active community make it adaptable.

Why Use PHP? Advantages and Benefits ExplainedWhy Use PHP? Advantages and Benefits ExplainedApr 16, 2025 am 12:16 AM

The core benefits of PHP include ease of learning, strong web development support, rich libraries and frameworks, high performance and scalability, cross-platform compatibility, and cost-effectiveness. 1) Easy to learn and use, suitable for beginners; 2) Good integration with web servers and supports multiple databases; 3) Have powerful frameworks such as Laravel; 4) High performance can be achieved through optimization; 5) Support multiple operating systems; 6) Open source to reduce development costs.

Debunking the Myths: Is PHP Really a Dead Language?Debunking the Myths: Is PHP Really a Dead Language?Apr 16, 2025 am 12:15 AM

PHP is not dead. 1) The PHP community actively solves performance and security issues, and PHP7.x improves performance. 2) PHP is suitable for modern web development and is widely used in large websites. 3) PHP is easy to learn and the server performs well, but the type system is not as strict as static languages. 4) PHP is still important in the fields of content management and e-commerce, and the ecosystem continues to evolve. 5) Optimize performance through OPcache and APC, and use OOP and design patterns to improve code quality.

The PHP vs. Python Debate: Which is Better?The PHP vs. Python Debate: Which is Better?Apr 16, 2025 am 12:03 AM

PHP and Python have their own advantages and disadvantages, and the choice depends on the project requirements. 1) PHP is suitable for web development, easy to learn, rich community resources, but the syntax is not modern enough, and performance and security need to be paid attention to. 2) Python is suitable for data science and machine learning, with concise syntax and easy to learn, but there are bottlenecks in execution speed and memory management.

PHP's Purpose: Building Dynamic WebsitesPHP's Purpose: Building Dynamic WebsitesApr 15, 2025 am 12:18 AM

PHP is used to build dynamic websites, and its core functions include: 1. Generate dynamic content and generate web pages in real time by connecting with the database; 2. Process user interaction and form submissions, verify inputs and respond to operations; 3. Manage sessions and user authentication to provide a personalized experience; 4. Optimize performance and follow best practices to improve website efficiency and security.

PHP: Handling Databases and Server-Side LogicPHP: Handling Databases and Server-Side LogicApr 15, 2025 am 12:15 AM

PHP uses MySQLi and PDO extensions to interact in database operations and server-side logic processing, and processes server-side logic through functions such as session management. 1) Use MySQLi or PDO to connect to the database and execute SQL queries. 2) Handle HTTP requests and user status through session management and other functions. 3) Use transactions to ensure the atomicity of database operations. 4) Prevent SQL injection, use exception handling and closing connections for debugging. 5) Optimize performance through indexing and cache, write highly readable code and perform error handling.

How do you prevent SQL Injection in PHP? (Prepared statements, PDO)How do you prevent SQL Injection in PHP? (Prepared statements, PDO)Apr 15, 2025 am 12:15 AM

Using preprocessing statements and PDO in PHP can effectively prevent SQL injection attacks. 1) Use PDO to connect to the database and set the error mode. 2) Create preprocessing statements through the prepare method and pass data using placeholders and execute methods. 3) Process query results and ensure the security and performance of the code.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Best Graphic Settings
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. How to Fix Audio if You Can't Hear Anyone
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Chat Commands and How to Use Them
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Atom editor mac version download

Atom editor mac version download

The most popular open source editor

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

SublimeText3 English version

SublimeText3 English version

Recommended: Win version, supports code prompts!