Why is stateless

NO, Rest APIs are always stateless, server will not store any information and it rely always on client. The dissertation by Roy Thomas Fielding. Internet MediaTypes. About Us. Contact Us. Privacy Policy.

Application State vs Resource State It is important to understand the between the application state and the resource state. REST statelessness means being free from the application state.

Statelessness helps in scaling the APIs to millions of concurrent users by deploying it to multiple servers. Any server can handle any request because there is no session related dependency. A stateless API is also easy to cache as well. Specific softwares can decide whether or not to cache the result of an HTTP request just by looking at that one request.

But some web applications may have to track the user's progress from page to page, for example when a web server is required to customize the content of a web page for a user. Solutions for these cases include:. What makes the protocol stateless is that the server is not required to track state over multiple requests, not that it cannot do so if it wants to.

This simplifies the contract between client and server, and in many cases for instance serving up static data over a CDN minimizes the amount of data that needs to be transferred. If servers were required to maintain the state of clients' visits the structure of issuing and responding to requests would be more complex.

As it is, the simplicity of the model is one of its greatest features. Because a stateless protocol does not require the server to retain session information or status about each communications partner for the duration of multiple requests.

HTTP is a stateless protocol, which means that the connection between the browser and the server is lost once the transaction ends. HTTP is called as a stateless protocol because each request is executed independently, without any knowledge of the requests that were executed before it, which means once the transaction ends the connection between the browser and the server is also lost.

What makes the protocol stateless is that in its original design, HTTP is a relatively simple file transfer protocol :.

There was no relationship maintained between one connection and another, even from the same client. This simplifies the contract between client and server, and in many cases minimizes the amount of data that needs to be transferred. If protocol HTTP is given as State full protocol,browser window uses single connection to communicate with web server for multiple request given to web application.

This may create the situation of reaching to maximum connections of web server even though most of the connections in clients are idle. As time progressed more and more stateful aspects were added for a myriad of reasons, including performance and security. Section 5.

Cookies and some other stateful mechanisms, or less obvious stateful mechanisms, are later HTTP additions. HTTP 1 is said to be stateless although in practice we use standardized stateful mechanisms, like cookies, TLS, and caching. Existing applications, even HTTP 1 applications, needing state will break if trying to use them statelessly. It may not be safe to assume that a particular HTTP 1 application does not use state. The server and client are aware of each other only during a current request.

Afterwards, both of them forget about each other. Due to this nature of the protocol, neither the client nor the browser can retain information between different request across the web pages. HTTP is stateless. TCP is stateful. We don't need anything to be maintained to make another HTTP request.

A connection header that is "keep-alive" means the TCP will be reused by the subsequent HTTP requests and responses, instead of disconnecting and re-establishing TCP connection all the time. Once the request is made and the response is rendered back to the client the connection will be dropped or terminated. The server will forget all about the requester. The web chooses to go for the stateless protocol. It was a genius choice because the original goal of the web was to allow documents web pages to be served to extremely large no.

The state of an application or anything else, really is its condition or quality of being at a given moment in time--its state of being. Whether something is stateful or stateless depends on how long the state of interaction with it is being recorded and how that information needs to be stored. A stateless process or application can be understood in isolation. There is no stored knowledge of or reference to past transactions.

Each transaction is made as if from scratch for the first time. Stateless applications provide one service or function and use content delivery network CDN , web, or print servers to process these short-term requests. You type your question into a search engine and hit enter. If your transaction is interrupted or closed accidentally, you just start a new one.

Think of stateless transactions as a vending machine: a single request and a response. Stateful applications and processes, however, are those that can be returned to again and again, like online banking or email. For these reasons, stateful apps use the same servers each time they process a request from a user.

If a stateful transaction is interrupted, the context and history have been stored so you can more or less pick up where you left off. Stateful apps track things like window location, setting preferences, and recent activity.

Like RESTful services, GraphQL-based services are entirely stateless, and give clients even more control over what data is fetched from servers. Incorporating a stateless solution to a web service or app has a number of advantages over an equivalent stateful implementation.

For starters, stateful server implementations are complex to configure. They require the ability to reference potentially multiple states, which could lead to a number of incomplete transactions and sessions throughout a system.

One of the biggest drawbacks of stateful architecture is its inability to scale easily and efficiently. If the state is managed server-side, it means each step in a long-running transaction has to be handled by the same server. The independence or loose coupling between client and server allows for more flexibility when developing a solution that would, otherwise, rely heavily on server-side complexity that is characteristic of stateful systems.

What this means for modern-day technology stacks is that they have become far more modular. Stateless architectures have increasingly advocated for the use of smaller, simpler microservices, which help move us away from the monolithic solutions of the past.

A business that has already implemented stateless services can more easily break separate functionality into different microservices. And a business that has already implemented microservices can more easily do a staged migration to the cloud, moving one service at a time without impacting the others. Compared to older patterns of monolithic, stateful services, this makes it easier to keep up with more modern demands of scaling globally and following agile methodologies to release new features far more frequently than was previously expected.

This, in turn, allows for easier horizontal scaling of services. Following these patterns, an e-commerce site, for example, can double or triple its capacity when there is demand, without having to pay for additional computing power when demand decreases. Based on these factors, choosing a stateless architecture for any modern-day, online service is almost always the correct path. While this example may be oversimplified, consider the key overarching takeaways of each implementation.