HTTP requests are stateless by design. However, this raises some questions regarding how to track user activities, including malicious ones, across requests so that you can collect metrics, block users, and make other decisions based on state. The only way to track user activities between one request and the next is to add a mechanism for storing events and categorizing them by client IP or other key.
Out of the box, HAProxy Enterprise Edition and HAProxy give you a fast, in-memory storage called stick tables. Originally, stick tables were created to solve the problem of server persistence. However, StackExchange, the network of Q&A communities that includes Stack Overflow, saw the potential to use them for rate limiting of abusive clients, aid in bot protection, and tracking data transferred on a per client basis. They sponsored further development of stick tables to expand the functionality. Today, stick tables are an incredibly powerful
Original URL: http://feedproxy.google.com/~r/feedsapi/BwPx/~3/mFEkQNL7xDw/