Web Crawler Framework: Scrapy Architecture Explained

What does the "skeleton" of the Scrapy framework look like?

Let's peel back the shell of Scrapy to take a look, this thing is essentially an assembly line factory. The crawler starts with start_urls and grabs the data, just like a courier sorter, and goes through downloaders, middleware, and pipelines. Here's a piece of trivia:Downloader middleware is where the proxy IPs are hidingThe 90% new hands can't find their way around.

Why Proxy IPs are Oxygen Tanks for Crawlers

To give a real case: an e-commerce site every hour to seal 300 IP, do not use the proxy, your crawler can not survive an episode. ipipgo's dynamic residential proxy pool, each request automatically change IP, like the crawler installed countless stuntman. Here to teach you a wild way - the proxy authentication written as middleware:

class ProxyMiddleware(object).
    def process_request(self, request, spider): proxy = "".
        proxy = "http://user:pass@gateway.ipipgo.com:9020"
        request.meta['proxy'] = proxy

Hands-on tuning of Scrapy's proxy settings

Don't be fooled by the official documentation, there is a way to configure it in practice. Adding these lines to settings.py is the way to go:

DOWNLOADER_MIDDLEWARES = {
    'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware': 400,
    'your_project.middlewares.ProxyMiddleware': 100
}

IPIPGO_API = "https://api.ipipgo.com/getproxy?type=json&count=5"

Remember to store the API key for ipipgo in an environment variable, don't be stupid and write it to death in your code. It is recommended to useRandom delay + auto-retryThe mechanism, together with ipipgo's 5-second switching package, the anti-blocking effect is pulled straight to full effect.

The Three Pitfalls of Proxy IP Use (with Escape Guide)

Five Soulful Questions Frequently Asked by White People

Q: Is it okay to use a free proxy?
A: Dude, have you ever seen a Michelin meal made from the rotten leaves you pick up at the food market? ipipgo's exclusive IP pool is the way to go.

Q: Why doesn't the proxy take effect after I set it?
A: First check the middleware order, then capture the packet to see the X-Forwarded-For field in the request header. ipipgo control panel has real-time traffic monitoring.

Q: Do I need to maintain my own IP pool?
A: It's not like opening a pig farm, ipipgo comes with 20 million+ dynamic IP pools, and also supports customization by geography, saving you time!

Q: What should I do if I encounter human verification?
A: ipipgo's dual-pronged approach of residential proxy + browser fingerprint emulation has been personally tested to bypass 90%'s CAPTCHA.

Q: How do I test if the proxy is working?
A: Print response.meta['proxy'] in parse method, or check the usage log in ipipgo backend.

Putting a "cloak of invisibility" on a reptile.

Lastly, I'd like to share a configuration plan for the bottom of the box: to connect ipipgo's API to the automatic scheduling system, with random UA and mouse track simulation. Remember to add an automatic alarm module in the scrapy extension, when the IP failure rate exceeds 10% automatically switch packages. This match down, your crawler will be able to gopher like in the target site to and from the free.

To be honest, the proxy IP is well chosen, the crawler off work early. I've used the enterprise version of ipipgo to realize what it means to be a good proxy."Once and for all.", the teams that build their own proxy pools end up going to work as security for the server room...