When building applications, you’ll inevitably have to decide whether to use stateless or stateful APIs. A stateless application has no memory of previous user interactions; it treats every interaction from a new user as the first interaction. On the other hand, a stateful application keeps track of all interactions between users and can build profiles based on these prior experiences.
The following discussion on stateless vs stateful can help you develop a thorough understanding of what can meet your specific needs. So, read on.
Stateful vs. stateless applications
Stateless applications
Stateless applications do not store any data from one request to the next. Instead, they use HTTP cookies and session IDs to identify each user. This means that an application can process tens of thousands of requests simultaneously without worrying about the impact on performance or scalability. Rather than dealing with an ever-growing database, stateless applications only need enough memory and CPU power to handle a single request at any given time—much simpler than managing stateful databases.
Stateful applications
Stateful applications store information on behalf of individual users using sessions or other techniques such as cookies. This allows them to retain some state between requests, which improves usability by allowing users to interact with your site without having to log in every time they visit it. The downside is that this requires more CPU power and RAM from your servers—and if you’re running hundreds or thousands of concurrent connections at once, you’ll need quite a bit more.
Stateless application example
In a stateless application, there is no need for a connection between the client and the server. When a client wants to use an application, it sends all of its requests to the server. The server processes these requests by generating new pages and sending them back to the client.
This makes it simple to scale applications so many users can be served at once. It also means that there is no limit on how large your system can grow—you can add more hardware as needed. This makes stateless applications great choices for high-performance websites or web services such as eCommerce sites or online games with many users.
Stateful application example
Consider you have an application that stores data in memory and maintains it as users interact with the system. The users enter their name into an input field, press submits, and are greeted with their details on the next page. To maintain user data between pages, we need to store this information in session variables or cookies so that they can be accessed by subsequent pages.
Key differences
The key differences you find while looking at stateless vs stateful APIs are that stateless applications do not store user data. Instead, they treat each request as new and unrelated to previous requests.
On the other hand, stateful applications store data and can use it to determine how to respond to subsequent requests from that user. This process is often referred to as session station or session tracking.
This difference might seem minor at first blush; what’s so significant about keeping track of one user? But if you’re looking for a way to increase speed and/or security without having your application bog down too much with overhead—or if you want something more secure than cookies, here, stateful applications may be helpful.
In summary, stateless and stateful are two different approaches to storing data. Stateless is more horizontally scalable and allows for faster data retrieval. At the same time, stateful provides greater data consistency and availability at the cost of increased storage space and latency when accessing data. So, ensure you have a good idea of the differences to optimise the performance of your business and improve its scalability.
