Stateful and Stateless Protocols

  • TCP is stateful, meaning that each request has some sort of knowledge of prior interaction

  • HTTP is stateless, meaning that each request is unaware of each other

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    ## HTTP Request Message

- Request
- Response

Request: METHOD PATH PROTOCOL\r\n

We supply the Host header, as "Virtual Hosts" can be set up -->

  • HTTP is all plain-text

Session State

As HTTP(s) requests are stateless, they cannot inherently pass data between different requests. To solve this problem, we can use cookies.

Browser cookies are locally stored pieces of data that are appended on to every request made to the server.

This allows us to maintain a form of persistence.

We might use cookies to identify ourselves to the server (ie a user)

  • Domain - The sites that the cookie applies to
  • Name - The key (name) of the cookie
  • Value - The value of the cookie
  • Expires - The time that the cookie will be valid for

Issues with Cookies

  • Privacy concerns - tracking