What's The Difference Between Stateless And Stateful Protocols

All network protocols for web browsers can be categorized into stateful and stateless.

State refers to the server’s ability to maintain session information. Let's look into both state types

Stateless

  • Stateless protocols do not retain information on the server, removing the issue of server-side state synchronization and data storage.
  • Because of this, they are scalable and can process requests fast.
  • Each stateless call to the server is independent of the previous and the next. Every call contains all the data it needs to be fully processed and executed independently.
  • If there is an error or system crash, there is no dependency on retrieving data because it is never stored.
  • By default, HTTP is stateless, making statelessness one of the principles of REST architecture and REST APIs.
  • If three HTTP calls are made to the server in succession, three separate connections are opened and closed one after the other.
  • However, HTTP Cookies can be created using HTTP Headers to create sessions by storing resource data in the browser.
  • Therefore HTTP by default is still stateless but not always sessionless.

Stateful

  • Stateful protocols require the server to save status and session information, such as an authentication session. 
  • This is achieved with heavy and complicated server-side software that is difficult to scale.
  • Stateful protocol examples are FTP and SOAP.
  • With stateful requests, previous calls can impact further calls. Because of this, stateful apps use the same servers for each request, and memory allocation is needed to store data.
  • Stateful apps also require higher security because sensitive session data is maintained.
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