A Web Crawler with Asyncio Coroutines

Re:A Web Crawler with Asyncio Coroutines by fsg7sdfg789 on Tuesday September 15, 2015 @04:27PM (#10222946)

It's not a significant number of pages per day, honestly. For me, the limiting factor is almost always how many concurrent requests I feel comfortable making to the remote server. For big sites, the proxy I use generally caps it at 5 req / domain (concurrently).

I generally use distributed crawlers, which means I can scale to millions of pages per day (assuming different domains). The biggest limiting factor is the database layer, how many writes can I do in a day.

If I need to go faster, I just spin up another crawler worker, which connects to the queue and starts pulling jobs.

I believe anything under a million pages / day should be do-able by a homebuilt, single-server system.

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Re:A Web Crawler with Asyncio Coroutines by fabiandesimone on Tuesday September 15, 2015 @04:39PM (#10223025)

Thanks. Well, this does make me wonder if we are doing something wrong or we are performing actions that are slowing down the crawling. We have a good server (I believe).

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Re:A Web Crawler with Asyncio Coroutines by troels on Tuesday September 15, 2015 @04:55PM (#10223147)

You might want to benchmark where your software is spending its time. A typical overhead is in the connection time. You may be able to speed things up with a local dns cache and by using http keep-alive. You also generally want to do a lot of parallel requests, since most time would be spent waiting for the subject site to respond.

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Re:A Web Crawler with Asyncio Coroutines by kawera on Tuesday September 15, 2015 @04:47PM (#10223076)

Don't forget to check your connection too; maybe you are filling it up or have latency issues.

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Re:A Web Crawler with Asyncio Coroutines by fsg7sdfg789 on Tuesday September 15, 2015 @06:25PM (#10223542)

I just reached out to you via email to see if I can help.

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