Hard Design: Web Crawler
A fetcher node crashes after popping a URL from the queue but before completing the crawl. How do you prevent URL loss?
— Tests your understanding of this concept.
Answer Options
A The URL is lost permanently
B Use in-flight tracking: mark URL as 'crawling' with TTL; if not completed in 5 minutes, return to queue
C Use a transaction log on the fetcher
D Duplicate all URLs in two queues
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See the Answer on Guru Sishya →This question is from the Design: Web Crawler topic (System Design Cases).
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