Difference Between Stateless And Stateful Protocol

What is Stateless Protocol?

Stateless means a communications protocol that treats each request as an independ- ent transaction that is unrelated to any previous request so that the communication consists of independent pairs of requests and responses. A stateless protocol is a type of network protocol that does not require the server to retain session information or status about each communications partner for the duration of multiple requests. In other words, Client send request to the server and server response back according to current state.

Examples of Stateless Protocol include:

  • IP (Internet Protocol)
  • HTTP (Hypertext Transfer Protocol)
  • UDP (User Datagram Protocol)
  • DNS (Domain Name System) etc

Stateless protocols improve the properties of visibility, reliability, and scalability. Visibility is improved because a monitoring system does not have to look beyond a single request in order to determine its full nature. Reliability is improved because it eases the task of recovering from partial failures. Scalability is improved because not having to store session state between requests allows the server to quickly free resources and further simplifies implementation.

Characteristics of Stateless Protocol

  • A stateless protocol is one in which the receiver is not required to keep session state from previous requests.
  • In stateless, server and client are loosely coupled and can act independently.
  • In Stateless Protocol each information packet travel on it’s own without reference to any other packet.
  • Each communication in Stateless Protocol is discrete and unrelated to those that precedes or follow.
  • The stateless protocol requires less resources because system do not need to keep track of the multiple link communications and the session details.
  • Using a stateless file server, the client must,specify complete file names in each request specify location for reading or writing re-authenticate for each request.
  • It does not have to implement the state accounting associated with opening, closing, and locking of files.
  • Stateless Protocols can generally handle transactions speedily.
  • Different servers can be used to process different information at a time.
  • Scaling architecture is relatively simple and easy.

Also Read: Difference Between Client-side Scripting And Server-side Scripting

What is Stateful Protocol?

A Stateful Protocol is a type of network protocol in which the client sends a server request and expects some sort of response. In case it doesn’t get a response, it then resends the intended request. The main characteristic of stateful is that it maintains the state of all its sessions, be it an authentication session, or a client’s request for information.

A good example of such a protocol is the File Transfer Protocol which, for example, remembers the identity of the client that is using it to download files. Another example is Telnet, through which, users can log on as a regular user with the privileges they are granted to the specific applications and data on that computer.

Stateful applications and processes, however, are those that can be returned to again and again, like online banking or email. They’re performed with the context of previous transactions and the current transaction may be affected by what happened during previous transactions. For these reasons, stateful apps use the same servers each time they process a request from a user.  

Stateful Protocol does not work better at the time of crash because stateful server have to keep the information of the status and session details of the internal states.

Characteristics of Stateful Protocol

  • Stateful Protocol require server to save the status and session information.
  • In stateful, server and client are tightly bound.
  • Stateful Protocols provide better performance to the client by keeping track of the connection information.
  • Stateful Application require Backing storage.
  • Stateful request are always dependent on the server-side state.
  • Using a Stateful,file server, the client can send less data with each request.
  • Stateful servers can also offer clients extra services such as file locking, and remember read and write positions.
  • Stateful Protocols handle transactions slower.
  • Same server must be utilised to process every request.
  • Scaling architecture is difficult and complex.

Also Read: Difference Between Client-server And Peer-to-Peer Network

Difference Between Stateless And Stateful Protocol In Tabular Form

DescriptionStateful Protocols require the server to save the state of a process.Stateless Protocols do not need the server to save the state of a process.
Response mechanismStateful expects a response and if no answer is received, the request is resent.In stateless, the client sends a request to a server, which the server responds to based on the state of the request.
Design complexityThis makes the design heavy and complex, since data needs to be stored.Server design is simplified in this case. 
Requirement of ServerServer is required to store and save status information and details of sessions.No server is needed for data storage.
DependencyServer and Client are tightly coupled, as in extremely interdependent on each other.Server and Client are more independent and hence, loosely coupled.
Transaction HandlingTransaction handling is relatively slow in the stateful protocol.This is relatively faster in stateless protocol.
ImplementationThey are logically heavy to implement.They are easy to implement.
Functioning after a crashSince stateful protocols need to store data regarding the sessions, once the crash occurs, all the stored data is lost. Hence, it doesn’t work very well after a crash occurs.In the event of a crash, stateless protocols work better because there doesn’t exist a state that needs to be restored. A server that failed during the crash can simply be restarted. 
DesignThe server design is complex to implement.The server design is simpler to implement.
Working StateThey react only by the current state of a transaction or request.They act independently by taking the previous or next request into consideration.
RequestsRequests are always dependent on the server-side.Requests are self contained and not dependent on the server-side.
UserbaseThese are a thing of the past, and the dynamic user base is very less.These are the future because more and more industries are moving towards statelessness.
Servers SpecificationsSame server must be utilised to process every request.Different servers can be used to process different information at a time.
Scaling ArchitectureScaling architecture is difficult and complex.It is relatively easier to scale architecture.
ProgrammingIt is difficult to code as one of the salient features here is data storage.It is much easier to code.
ExamplesHTTP, UDP (User Datagram Protocol), DNS (Domain Name System), etc.Telnet, FTP (File Transfer Protocol), etc.

Also Read: Difference Between FTP And TFTP