Google API rate limiting

Question

Google limits the actual API calls one can make to their servers. I know for a fact that this rate is dynamic i.e. they determine dynamically what number of requests after which the server should start blocking requests.

I have 2 questions -

1. How does Google do it? i.e. dynamically figure out (maybe based on the load/bandwidth usage) the limit rate.
2. how can I optimally fire requests to their API's without getting blocked.

thanks.

Answer 1

Google checks your IP address and blocks it if you have too many requests in some amount of time.

If you're planning on having many requests to Google in a short amount of time, they'll usually win and block you with a captcha based on your IP.

So you can either get access to multiple IPs to do what you're doing, or better yet throttle your requests so you don't run afoul of them.