To set the request frequency limit for anti-crawler on e-commerce platforms, you can implement rate limiting mechanisms to control the number of requests a client can make within a specific time window. This helps prevent abuse from bots or crawlers while ensuring legitimate users have smooth access.
Key Methods to Set Request Frequency Limits
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Token Bucket Algorithm
- Allocates a fixed number of tokens per second. Each request consumes a token. If tokens are exhausted, requests are delayed or rejected.
- Example: Allow 100 requests per minute per IP.
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Fixed Window Counter
- Tracks requests in fixed time intervals (e.g., 1 minute). If the count exceeds the threshold, further requests are blocked.
- Example: Block an IP if it makes more than 50 requests in 60 seconds.
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Sliding Window Log
- Records timestamps of each request and removes outdated ones. If the remaining requests exceed the limit, block the request.
- Example: Allow 10 requests per 10 seconds, sliding the window dynamically.
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User-Agent & IP Filtering
- Block suspicious User-Agents (e.g., "Python-urllib") or high-frequency IPs.
- Example: Restrict IPs making more than 200 requests/hour.
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CAPTCHA Challenges
- Require human verification for suspicious traffic.
- Example: Trigger CAPTCHA after 5 rapid requests from the same session.
Implementation with Tencent Cloud Services
- Tencent Cloud API Gateway: Configure rate limiting policies to restrict requests per IP or API key.
- Tencent Cloud WAF (Web Application Firewall): Set custom rules to block excessive requests and filter malicious traffic.
- Tencent Cloud Anti-DDoS: Mitigate high-volume crawler attacks with traffic scrubbing.
Example: In Tencent Cloud API Gateway, you can define a rate limit of 1,000 requests per minute per API key, automatically throttling excessive traffic.