Crawler distributed proxy IP pool building: Scrapy middleware development tutorials

First, why does your crawler need a distributed proxy IP pool?

When you are doing data crawling with Scrapy, have you ever encountered a situation where your IP is suddenly blocked? Ordinary stand-alone IP pool is like a log bridge, once blocked the whole crawler is paralyzed. This time you need toDistributed Proxy IP Pool--It enables multiple servers to share IP resources, and other machines automatically take over the task when one node is blocked. With ipipgo's residential proxy IP, the real home network IP is replaced for each request, dramatically reducing the risk of being recognized by websites as machine traffic.

Second, three minutes to build the basic agent middleware

Creating a Scrapy project inmiddlewares.pydocument, the core code is really just five steps:
1. Obtaining a dynamic IP from the ipipgo API
2. Automatic processing of authorization validation
3. Abnormal IP automatically rejected
4. Automatic retry of failed requests
5. Real-time statistics on IP usage

class IpProxyMiddleware.
    def __init__(self, api_url).
        self.proxy_pool = [] Access the ipipgo API here.
        self.bad_proxies = set()

    def process_request(self, request, spider): proxy = self._get_proxies = set()
        proxy = self._get_proxy()
        request.meta['proxy'] = f "http://{proxy['ip']}:{proxy['port']}"
        request.headers['Proxy-Authorization'] = proxy['auth']

III. Key Design Points for Distributed Architecture

Pay attention to these details when using Redis for shared storage:
- Storing IP scores using the Sorted Set structure
- Synchronization of IP states of different crawler nodes via subscription channels
- Hourly automatic cleaning of low quality IPs
- Dynamically adjust the IP allocation strategy for different websites

Fourth, the actual test effect to enhance the skills

We found in the e-commerce website real test: after using ipipgo residential proxy IP, the request success rate increased from 63% to 97%. the key tips are:
- Separate IP change frequency for each domain name
- Automatic switching of IP types based on response time
- Automatically switch to static IP in the morning hours
- Enabling HTTPS proxies for CAPTCHA-prone websites

V. Five major potholes that must be avoided

1. Authorization information leakage: Don't hard-code the key in the code, pass it with an environment variable
2. IP Reuse: Set a reasonable TTL, dynamic IP is recommended to be changed in 3 minutes
3. Wrong choice of geography: Match the location of the target website with ipipgo's pinpointing function.
4. Agent Type Confusion: Data center IPs for data-based sites, residential IPs for strong anti-climbing sites.
5. Ignoring response latency: Setting up timeout fusing mechanism, switching IPs immediately when the delay is more than 2 seconds

Frequently Asked Questions QA

Q: How to verify if the proxy IP is effective?
A: Add debugging code to the middleware to print the actual IP address used, comparing it to the IP usage record shown on the ipipgo console.

Q: What should I do if I encounter a 407 agent authentication error?
A: Check whether the authorization header format is correct. It is recommended to use the SDK provided by ipipgo to handle the authentication process automatically to avoid errors in manually splicing strings.

Q: How do I choose the right agency agreement?
A: Follow this principle: you need high stash to choose socks5, you need to use HTTPS for certificate access, and use HTTP for ordinary web pages. ipipgo's full protocol support is just right to meet the switching needs of multiple scenarios.

With this solution, the crawler cluster managed by our team has been running stably for more than 2 years. Especially, ipipgo's 90 million+ residential IP resources, together with their intelligent routing function, can automatically match the most suitable exit IP for the current website, which is the key to maintain high availability. It is recommended to try their API interface first to experience the effect of IP switching in a real environment.