What are the steps to use redis long connection in php-PHP Tutorial-php.cn

Home

Backend Development

PHP Tutorial

What are the steps to use redis long connection in php

php中世界最好的语言

May 18, 2018 pm 02:47 PM

php redis step

This time I will bring you the steps for using redis long connection in php, and what are the precautions for using redis long connection in php. The following is a practical case, let's take a look.

php-redis project address on github: https://github.com/phpredis/phpredis

pconnect function declaration

Time_out indicates how many seconds the client will be idle before disconnecting. The function connection returns true if successful and false if failed:

pconnect(host, port, time_out, persistent_id, retry_interval)
    host: string. can be a host, or the path to a unix domain socket
    port: int, optional
    timeout: float, value in seconds (optional, default is 0 meaning unlimited)
    persistent_id: string. identity for the requested persistent connection
    retry_interval: int, value in milliseconds (optional)

Copy after login

The following example details the reuse of pconnect connections.

$redis->pconnect('127.0.0.1', 6379);
$redis->pconnect('127.0.0.1'); // 默认端口6379,跟上面的例子使用相同的连接。
$redis->pconnect('127.0.0.1', 6379, 2.5); // 设置了2.5秒的过期时间。将是不同于上面的新连接
$redis->pconnect('127.0.0.1', 6379, 2.5, 'x'); //设置了持久连接的id，将是不同于上面的新连接
$redis->pconnect('/tmp/redis.sock'); // unix domain socket - would be another connection than the four before.

Copy after login

Introduction to the use of pconnect

A brief description of the pconnect method

Use this method to create a connection , the connection will not be closed after calling the close method, the connection will only be closed after the process ends.

[To be verified] If you are using a long connection, the timeout configuration item in the Redis configuration file needs to be set to 0, otherwise the connection in the connection pool will expire due to timeout.

Explain pconnect for PHP-FPM

Long connections will only end after the PHP-FPM process ends, the

life cycle of the connection is the life cycle of the PHP-FPM process. Compared with shorter connections, a redis connection will be generated during each PHP-FPM call. The representation on the server is excessive time_out connection status.
On the contrary, long connections, all CGIs called by PHP-FPM will only share one long connection, so only a fixed number of time_out will be generated.

Close long connections

You can call the close and unset methods, but they are very different:

close The function is only to prevent the current PHP process from making redis requests, but it cannot actually close the long redis connection. The connection will still be reused in subsequent requests until the FPM process life cycle ends. So close does not destroy the redis object, it just disconnects it.

unset The variable will be destroyed. It should also be noted that you do not need to close if you use pconnect. If the current script execution time is very long, it will always occupy a connection.

How to determine whether the current Redis is in the connected state

The equivalent problem is to determine whether the current instance is valid in

single case mode.

It is customary to call echo to determine whether the string itself is returned normally, or call ping to see whether the return value is PONG.

But you need to be particularly careful. After redis disconnects, when calling echo and ping (returning 'POMG'), an exception

will be thrown. So it needs to be handled through the exception catching mechanism.

Code analysis of pconnect connection reuse issues

Situation 1: Non-singleton mode.

Explanation: Instance a and instance b share a connection, and instance b modifies the connection of instance a:

So the following example causes the final value of instance $a to become 2 , requires special attention.

$a = pconnect(host, port, time_out);
select(3);
$a -> setex(id, 3);
echo $a -> get(id);
//之后执行下面的连接
$b = pconnect(host, port, time_out);
select(2);
$b->set(id,2)
echo $a->get(id);  //这个id操作的db变成了2，不再是之前的3了。因为这两个连接共用了一个连接通道。

Copy after login

Scenario 2: Singleton mode.

Modify the above code so that both a and b are generated through getInstance. The prerequisite for generation is to determine whether the current instance exists. The confusion point of the singleton mode is:

$a generates an instance. At this time, $b is generated. $b uses the instance of $a, and then modifies the connection of $a. Then calling $a must be The modified instance of $b called. Same as situation two.

The code for singleton mode is as follows:

public static function getInstance($db = 0)
{
  if (!isset(self::$_instance)) {
    self::$_instance = new Redis();
  }
  self::_connect();
  self::$_instance->select($db);
  return self::$_instance;
}

Copy after login

Both cases illustrate the problem of connection reuse. How to fix this bug? Two points:

1. Generate a single instance for each db.

2. Avoid connection reuse issues.

So the code can be adjusted to return a singleton array:

public static function getInstance($db = 0)
{
  try{
    if (isset(self::$_instance[$db]) && self::$_instance[$db]->Ping() == 'Pong') {
      return self::$_instance[$db];
    }
  } catch (Exception $e) {
  }
  self::$_instance[$db] = new Redis();
  self::_connect($db);
  return self::$_instance[$db];
}

Copy after login

Things to note

Avoid using the Use redis objects in class member variables.

In the singleton mode of redis, the expiration time of time_out is declared. If the occasion for redis processing is a task, and the interval between task calls to redis is relatively long. When the interval is greater than time_out, redis will disconnect, and all operations on redis will fail. The solution is to avoid this calling method and execute it by dynamically declaring the redis class at the place of call. This problem does not distinguish between long connections and short links, and it is an error in the calling method.

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

Hot AI Tools

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress images for free

Clothoff.io

AI clothes remover

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

How to fix KB5055523 fails to install in Windows 11?

3 weeks ago By DDD

How to fix KB5055518 fails to install in Windows 10?

3 weeks ago By DDD

Roblox: Dead Rails - How To Tame Wolves

4 weeks ago By DDD

Strength Levels for Every Enemy & Monster in R.E.P.O.

4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Roblox: Grow A Garden - Complete Mutation Guide

2 weeks ago By DDD

Hot Tools

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

Java Tutorial

1660

CakePHP Tutorial

1416

Laravel Tutorial

1311

PHP Tutorial

1261

C# Tutorial

1234

Related knowledge

PHP and Python: Code Examples and Comparison Apr 15, 2025 am 12:07 AM

PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.

PHP's Purpose: Building Dynamic Websites Apr 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 and Python: Different Paradigms Explained Apr 18, 2025 am 12:26 AM

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP: Handling Databases and Server-Side Logic Apr 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.

Choosing Between PHP and Python: A Guide Apr 18, 2025 am 12:24 AM

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

Why Use PHP? Advantages and Benefits Explained Apr 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.

PHP and Python: A Deep Dive into Their History Apr 18, 2025 am 12:25 AM

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

PHP's Impact: Web Development and Beyond Apr 18, 2025 am 12:10 AM

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

See all articles