Shulou(Shulou.com)06/03 Report--

This article mainly introduces what programming language is most suitable for crawlers, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, let the editor take you to understand it.

In the early days, crawlers used to be done with C _ Java,Python +, but it was more tedious, and then people began to use a lot of well-designed scripting languages, because these two languages are most suitable for crawlers.

The most important part of a high-performance web crawler is the synchronization of (many) parallel instances, running on multiple machines.

A very rough rule of thumb is that a single machine with saturated 10Mbps connections performs well, there are hundreds of large search engines running, and the basic function of each crawler is very simple and almost trivial, because it includes getting pages and extracting links from them.

Because multiple instances are running in parallel, the main challenge is to detect duplicates in real time, because you never want to click on the target page multiple times and comply with robots.txt constraints in real time in all of these instances.

All of this is tricky because cross-instance timing is uncertain and unpredictable, so a lot of synchronization must be done to ensure that each site complies with robots.txt constraints.

Therefore, languages with built-in threads such as Java are very suitable in this respect. In both Vast.com and Wowd, we use Java specifically for crawling.

It is important not to confuse fetching with fetching / wrappers / web clients to do some extraction / processing.

Thank you for reading this article carefully. I hope the article "what programming language is most suitable for crawlers" shared by the editor will be helpful to everyone. At the same time, I also hope that you will support and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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