Stateful Webservice

up vote4down votefavorite 1

Possible Duplicate stateful webservices I have a need for a stateful webservice in our organization. However, everywhere I read online says that building a stateful webservice is bad programming but nothing ever says why. I guess I don't understand what is so bad about it. I also don't really understand why they would give a work around to allow you to have state in a webservice. So I guess that my question is, why is it bad programming to use a stateful webservice and why would it be allowed? web-services stateful share|improve this question edited Sep 22 at 12:58 Benjamin 5,60032265 asked Jun 12 '09 at 20:13 Justin Balvanz 8462917

2   I'd look at this in a different way--what does this service need to do that is stateful? Can that be creativly smoke and mirror'd? –  Wyatt Barnett Jun 12 '09 at 20:16 add comment

3 Answers

activeoldestvotes

up vote12down voteaccepted

The whole purpose of a web service is to deliver a piece of functionality in one transaction in a way that is highly scalable. This means keeping things simple and atomic. When you have to make multiple calls to perform the operation, you have a great potential of leaving transactions hanging. Is the client coming back? Are they done? How long should the transaction remain open? Did they crash? How should rollbacks be handled? The answers to these questions could have a radical impact on the resources necessary to run your service. Which is why everyone recommends doing it all in one swoop. share|improve this answer answered Jun 12 '09 at 20:59 Chris Lively 56.4k1083163

2   Excellent answer! Also, if your operation is stateful, what happens if the server fails? (And it will. That's why we run clusters of servers.) All state will be lost. Stateless allows you to resubmit the request to the next server in the cluster as if nothing happened. –  Devon_C_Miller Mar 16 '12 at 10:48 add comment

up vote6down vote

Here are some reasons I can think of: The cost of maintaining state will have to be borne server side only - service consumers are rarely web browsers, so have no cookies. This brings down your server performance and increases your design complexity. A service consumer is an intelligent program, rather than a dumb browser. As such the program will (almost always) maintain its own state. In other words, when you provide a service, your consumer will request precisely the data it wants. Maintaining state on the server becomes obsolete and unnecessary. Transactions - a service is a dangling point in your system because its clients are mostly intelligent, and they decide when to inform you of changes in their state. This means that if you maintain state, you might have to wait between service calls to finish a transactional operation. Any there's absolutely no guarantee that the client will ever make that next service call. There are a lot of reasons, but these are the ones I can think of off the top of my head :) share|improve this answer answered Jun 12 '09 at 21:05 Sudhir Jonathan 6,1182151

add comment