GraveHag / CyberspaceSpider

CyberspaceSpider is a visualization-based web crawling project that maps the path a web crawler takes as it navigates through the internet. With CyberspaceSpider, you can gain insights into the structure of the web and the relationships between different sites. It is a simple and intuitive tool that provides a unique perspective on web crawling.
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Implementing a web crawler that respects crawl delay from robots.txt #15

Open GraveHag opened 1 year ago

GraveHag commented 1 year ago

1) Use a WebClient to download the robots.txt file for the website you want to crawl. The robots.txt file should be located at the root of the website, so you can construct the URL by appending "/robots.txt" to the website's base URL.

2) Parse the robots.txt file and extract the Crawl-delay directive for your crawler. The Crawl-delay directive specifies the number of seconds to wait between requests. If the directive is not present or cannot be parsed, use a default delay time.

3) When making requests to the website, add a delay between requests to respect the crawl delay specified in the robots.txt file. You can use the Thread.Sleep method to pause the execution of your code for the appropriate number of seconds.

4) Monitor the rate at which you are making requests and adjust the crawl delay as needed to ensure you are not overloading the website. You can also use the User-agent directive in the robots.txt file to specify a custom user agent for your crawler, which can help website administrators identify your crawler and adjust their policies accordingly.