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

This article mainly introduces "how to solve the IP blacklist". In the daily operation, I believe many people have doubts about how to solve the IP blacklist problem. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts about "how to solve the IP blacklist". Next, please follow the editor to study!

1. What problems should web crawlers pay attention to:

The most important thing to consider when building a crawler is not to overload the original server. Nowadays, many servers take a rather hostile attitude towards crawlers. If you push too hard on a website, it will blacklist the IP address of your crawler. Once blacklisted, they will limit you to one or fewer queries per minute, effectively preventing you from crawling their site.

two。 Resolve the IP blacklist problem:

The problem of IP being pulled into the blacklist should often occur. After all, the efficiency of fully controlling the crawling speed is too slow. The simplest solution is to replace a highly anonymous ip agent used by the crawler, such as Sun http, which can extract ip directly from the proxy website for replacement. After replacement, it will be much smoother to enter the website to crawl, because at this time you are using a brand new ip and will be blocked by the website in time. You can also crawl with another one.

PS: in addition, you need to know something else:

(1) appropriate support for robots.txt.

(2) automatic throttling based on original server bandwidth and load estimation.

(3) automatic throttling based on the estimation of the frequency of the original content change.

(4) site administrator interface, where site owners can register, verify, and control the rate and frequency of crawls.

(5) understand the virtual host and throttle through the original IP address.

(6) support some form of machine-readable site map.

(7) correct crawl queue priority and ordering.

(8) reasonable duplicate domain and duplicate content detection to avoid re-crawling the same site in different domains.

(last.fm and lastfm.com, and 1 million other sites that use multiple domains for the same content. )

(9) learn about the GET parameters and what the "search results" are in many site-specific search engines.

For example, some pages may use certain GET parameters to link to search results pages in another site's internal search. You may not want to crawl these results pages.

(10) learn about other common link formats, such as login / logout links.

Then you can extract all the information from the crawled page, which is very important.

At this point, on the "web crawler how to solve the IP blacklist" study is over, I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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