A Framework for Designing Large-Scale Distributed Crawler Systems

First, why crawlers have to use proxy IP, this thing in the end how important

Crawlers have been engaged in the old iron know, now the site's anti-climbing mechanism than the security door is also strict. To give you a chestnut, you wrote a crawler script, the results of running half an hour to be blocked IP, this time if there is no proxy IP support, the whole project directly cool. This is why all serious crawler projects now have to use proxy IPs as oxygen tanks.

A word of caution is necessary here:Don't use those free agents.. The free IP pool on the market is like a toilet in a public restroom, who have used it, not to mention the slow speed, but also may be blacklisted by the website at any time. Let's do the project, or have to find like ipipgo this professional service provider, his family IP pool updated every day more than 8 million resources, the survival rate can be 95% or more.

Second, how to build a distributed crawler system four beams and eight pillars

The skeleton of the whole system has to be designed this way (note the table for more clarity):

Focus on the proxy IP scheduling strategy. It is recommended to integrate the ipipgo API directly into the crawler node, and set up a smart switching rule: for example, if 3 consecutive requests fail, or if the response time exceeds 2 seconds, the IP replacement will be triggered immediately. Measured, this can collect the success rate from 40% directly to 90% up.

III. Five life-preserving techniques in actual combat

1. Don't be too gung-ho about IP rotationThe IP address of the website can be used in the following ways: don't be silly and use IPs in order, mix them with IPs from different regions and carriers. ipipgo background can be set to rotate the strategy, such as changing IPs every 50 requests, or adjusting the anti-climbing pattern of the target website.

2. The requesting head has to be able to do tricks.: Don't let all crawler nodes use the same User-Agent. combine ipipgo's IP assignment with UA masquerading, with different browser fingerprints for each IP, so that the site is harder to recognize.

3. There's something to be said for speed control.Don't think that you can build vigorously by using proxy IP. It is recommended to adjust dynamically according to the response speed of the target website. ipipgo's intelligent QPS regulation function can automatically match the optimal collection frequency.

Fourth, the real project stepped on the actual record

Last year, I helped an e-commerce company to do price monitoring, and at first I used an ordinary proxy IP, which triggered hundreds of CAPTCHAs per hour. Change to ipipgoDynamic Residential AgentsAfter that, the IP switching interval was set to 15 seconds, and with their request fingerprinting masquerade service, the CAPTCHA trigger rate dropped directly below 5%.

Here is a tawdry operation: the crawler nodes are distributed in 10 different regions of the server, each node is bound to ipipgo's specific geographical IP pool. For example, to climb the data in East China, Shanghai, Hangzhou IP, so that the collection efficiency is more than two times higher than the messy IP.

V. Frequently Asked Questions QA

Q: What should I do if my proxy IP is always blocked?
A: Check three places: ① is not using a transparent proxy (must use the high stash proxy) ② single IP request is too dense ③ is the lack of the necessary request header camouflage. It is recommended to go directly to ipipgo's commercial-grade solution, they have packaged these issues.

Q: Which is better, dynamic IP or static IP?
A: Look at the use of the scene. Dynamic IP is suitable for large-scale collection (ipipgo can change 5000+ IPs per minute), and static IP is suitable for the scenario that requires login status. But now ipipgo's exclusive IP pool combines the two advantages and supports on-demand switching.

Q: How do I break the CAPTCHA when I encounter it?
A: Do not just hard, on the three axes: ① reduce the frequency of individual IP requests ② increase the mouse movement track simulation ③ with ipipgo's CAPTCHA whitelist IP pool. If you can't, you can take over the coding platform, but the cost will soar.

Finally, to be honest, to do distributed crawler is like playing guerrilla warfare, proxy IP is your ammunition depot. Choose the right service provider can really take three years less detour, like ipipgo can provide a complete anti-anti-crawling solution, used to know really save a lot of heart. Any specific problem can go directly to their official website to find technical customer service, reply speed than ordinary business several orders of magnitude faster.