What is a web crawler: working principle and proxy IP anti-blocking strategy

What the hell is a web crawler?

Simply put, it is a robot that grabs data online. For example, if you want to compare the price of online shopping commodities, manually check 100 websites to die of exhaustion, the crawler can automatically help you to the price of all the data raked down. This goods 24 hours a day, according to the set rules in the website scurrying around, hundreds of times more efficient than manual.

However, the site is not stupid, found abnormal access immediately pull black. Like a supermarket found someone with a book to copy all the prices of goods, the security guards must come to drive people. This time it is necessary toproxy IPTo cover up, let the crawlers disguise themselves as different "customers" to enter the store.

How did the crawler get blocked?

Three typical rollover sites:

Last year, there is a price comparison platform old brother, with their own broadband IP to catch the data, the results of the next day the entire company's network was the target site black, even the normal business is affected, the blood loss of more than ten thousand dollars.

How does a proxy IP work as a talisman?

Focus on three masterpieces:

1. Dynamic Change of Vests: like ipipgo's dynamic residential IP, every time you visit automatically change the new IP, the site can not tell whether it is a real person or a robot!

2. Fake Real Tracks: Replacing server room IPs with residential IPs, randomizing access intervals to mimic the rhythm of human operations

3. multipoint blossom strategy: Simultaneous scheduling of multiple regional IPs to avoid excessive traffic on a single entry point

 Python example: IP rotation with ipipgo's API
import requests

def get_proxy():
    api_url = "https://api.ipipgo.com/getproxy?type=dynamic"
    return requests.get(api_url).json()['proxy']

for page in range(100):: proxies = {"http": get_proxies.json('proxy')
    proxies = {"http": get_proxy(), "https": get_proxy()}
    data = requests.get(f'https://target.com/page/{page}', proxies=proxies)
    print(f "Page {page} of data has been crawled")

What are the doors to look for when choosing a proxy IP?

The market is a mixed bag, so remember these three guidelines for avoiding pitfalls:

① Don't be cheap and use free proxies: Not to mention the slow speed, 80% are all blackmail abandoned IPs

② Residential IP > Server Room IPEnterprise-level acquisition with ipipgo's static residential IPs, $35/each/month is more cost-effective than building your own proxy pool!

(iii) The agreement should be completeHTTP/HTTPS/Socks5 must be supported, like some websites use Socks5 protocol to catch the data.

Why do you recommend ipipgo?

This one does have a lot of tawdry action:

• Dynamic IP price rolls up to $7.67/GB for small teams
• 200+ countries IP pool, do cross-border e-commerce can accurately catch local data
• The client comes with smart routing, which works with two clicks of a small white dot
• I met a team doing overseas questionnaires, using their TK dedicated IP line, the collection efficiency directly tripled!

Frequently Asked Questions QA

Q: Dynamic IP and static IP in the end what is the difference?
A: Dynamic IP is automatically changed every time you network, suitable for high-frequency collection; static IP is fixed, suitable for the business that needs to log in status.

Q: How can I find out in time if my IP is blocked?
A: Add a detection module in the crawler, when 3 consecutive requests return 403 status code, immediately switch to the new IP

Q: Can I try ipipgo?
A: New registration to send 500MB flow, enterprise users can also apply for 1v1 program customization, customer service response faster than a delivery boy!

Final Rant:Being a crawler is like fighting a guerrilla war, and it's crucial toHiding, running and changing.. Choosing the right proxy IP service provider can make the data collection business twice the effort with half the effort. Especially for long-term projects, it is recommended to go directly to the enterprise version of the package, the cost of more than 9 yuan 1GB is much cheaper than recruiting programmers.