


PHP and phpSpider: How to deal with performance issues in large-scale data crawling?
With the development of the Internet and the popularity of data, more and more companies and individuals have begun to pay attention to data crawling to obtain the required information. In large-scale data crawling tasks, performance is an important consideration. This article will introduce how to use PHP and phpSpider to deal with the performance issues of large-scale data crawling, and illustrate it through code examples.
1. Use multi-threading
When crawling large-scale data, using multi-threading can significantly improve the running efficiency of the program. Through PHP's multi-threading extensions (such as the PHP pthreads extension), multiple crawling tasks can be performed simultaneously in one process. The following is a sample code using multi-threading:
<?php $urls = array( 'https://example.com/page1', 'https://example.com/page2', 'https://example.com/page3', // 更多待爬取的URL ); $threads = array(); // 创建线程 foreach ($urls as $url) { $thread = new MyThread($url); $threads[] = $thread; $thread->start(); } // 等待线程执行完毕 foreach ($threads as $thread) { $thread->join(); } class MyThread extends Thread { private $url; public function __construct($url) { $this->url = $url; } public function run() { // 在这里写爬取逻辑 // 使用$this->url作为爬取的URL } } ?>
2. Optimize network access
When crawling data, network access is one of the bottlenecks of performance. In order to improve the efficiency of network access, you can use excellent HTTP client libraries such as curl library or Guzzle to implement functions such as parallel requests and connection pool management.
The following sample code demonstrates how to use the Guzzle library for parallel execution of multiple requests:
<?php require 'vendor/autoload.php'; // 请确保已安装Guzzle库 use GuzzleHttpClient; use GuzzleHttpPool; use GuzzleHttpPsr7Request; $urls = array( 'https://example.com/page1', 'https://example.com/page2', 'https://example.com/page3', // 更多待爬取的URL ); $client = new Client(); $requests = function ($urls) { foreach ($urls as $url) { yield new Request('GET', $url); } }; $pool = new Pool($client, $requests($urls), [ 'concurrency' => 10, // 并发请求数量 'fulfilled' => function ($response, $index) { // 在这里处理请求成功的响应 // $response为响应对象 }, 'rejected' => function ($reason, $index) { // 在这里处理请求失败的原因 // $reason为失败原因 }, ]); $promise = $pool->promise(); $promise->wait(); ?>
3. Reasonable use of cache
In large-scale data crawling, often access Same URL multiple times. In order to reduce the number of network requests and improve program performance, caching mechanisms (such as Memcached or Redis) can be reasonably used to store crawled data. The following is a sample code that uses Memcached as a cache:
<?php $urls = array( 'https://example.com/page1', 'https://example.com/page2', 'https://example.com/page3', // 更多待爬取的URL ); $memcached = new Memcached(); $memcached->addServer('localhost', 11211); foreach ($urls as $url) { $data = $memcached->get($url); if ($data === false) { // 如果缓存中没有数据,则进行爬取并存入缓存 // 爬取逻辑略 $data = $result; // 假设$result为爬取得到的数据 $memcached->set($url, $data); } // 使用$data进行后续数据处理 } ?>
Through reasonable use of cache, repeated network requests can be reduced and the efficiency of data crawling can be improved.
Summary:
This article introduces how to use multi-threading, optimize network access, and rationally use cache to deal with performance issues of large-scale data crawling. Code examples show how to use PHP's multi-thread extension, Guzzle library and caching mechanism to improve crawling efficiency. In actual applications, other methods can be used to further optimize performance depending on specific needs and environments.
The above is the detailed content of PHP and phpSpider: How to deal with performance issues in large-scale data crawling?. For more information, please follow other related articles on the PHP Chinese website!

php把负数转为正整数的方法:1、使用abs()函数将负数转为正数,使用intval()函数对正数取整,转为正整数,语法“intval(abs($number))”;2、利用“~”位运算符将负数取反加一,语法“~$number + 1”。

实现方法:1、使用“sleep(延迟秒数)”语句,可延迟执行函数若干秒;2、使用“time_nanosleep(延迟秒数,延迟纳秒数)”语句,可延迟执行函数若干秒和纳秒;3、使用“time_sleep_until(time()+7)”语句。

php除以100保留两位小数的方法:1、利用“/”运算符进行除法运算,语法“数值 / 100”;2、使用“number_format(除法结果, 2)”或“sprintf("%.2f",除法结果)”语句进行四舍五入的处理值,并保留两位小数。

判断方法:1、使用“strtotime("年-月-日")”语句将给定的年月日转换为时间戳格式;2、用“date("z",时间戳)+1”语句计算指定时间戳是一年的第几天。date()返回的天数是从0开始计算的,因此真实天数需要在此基础上加1。

php判断有没有小数点的方法:1、使用“strpos(数字字符串,'.')”语法,如果返回小数点在字符串中第一次出现的位置,则有小数点;2、使用“strrpos(数字字符串,'.')”语句,如果返回小数点在字符串中最后一次出现的位置,则有。

方法:1、用“str_replace(" ","其他字符",$str)”语句,可将nbsp符替换为其他字符;2、用“preg_replace("/(\s|\ \;||\xc2\xa0)/","其他字符",$str)”语句。

在PHP中,可以利用implode()函数的第一个参数来设置没有分隔符,该函数的第一个参数用于规定数组元素之间放置的内容,默认是空字符串,也可将第一个参数设置为空,语法为“implode(数组)”或者“implode("",数组)”。

php字符串有下标。在PHP中,下标不仅可以应用于数组和对象,还可应用于字符串,利用字符串的下标和中括号“[]”可以访问指定索引位置的字符,并对该字符进行读写,语法“字符串名[下标值]”;字符串的下标值(索引值)只能是整数类型,起始值为0。


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

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

WebStorm Mac version
Useful JavaScript development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

SublimeText3 Chinese version
Chinese version, very easy to use

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

Dreamweaver Mac version
Visual web development tools
