CODEWITHSUNDEEP
c#wcfiis-7.5
kamilkp
kamilkp

Reputation: 9800

Keep a WCF Service alive under IIS

i have thoroughly searched the internet (most of the links sent me to stackoverflow ;)) to try to come up with a solution how to keep a WCF Service alive under IIS (7.5).

Many of the responses here were suggesting to write an application that will periodically send dummy requests to the WCF service in order to keep it alive.

My question is: what if I create a thread in the WCF which will start when a service is first called (in a static constructor) that will periodically consume the WCF itself?

I mean for example in c#:

while (true)
{
     WebClient client = new WebClient();
     string returnString = client.DownloadString("http://...");
     Thread.Sleep(1000 * 5);
}

assuming that "http://..." is an URI to a provided WebMethod which for example returns some integer.

Would that work?

Basically I need some kind of web service (not particulary a WCF but not a Windows Service) that is running on a server that performs some operations and updates something in a SQL Server database. So if the described approach will not work, what might be the best way to achieve this?

Upvotes: 6

Views: 7003

Answers (5)

Casper Leon Nielsen
Casper Leon Nielsen

Reputation: 2566

What you are doing is basically wrong from the outset.

The problem is this: IIS is basically a stateless request broker for http requests (basic IIS) and a request broker for service requests (IIS w. AppFabric).

What you are asking for is how to turn the inherently stateless IIS into a stateful server, with eternal threads running.

That is not what IIS does, IIS handles requests and its AppDomain is subject to AT ALL TIMES be torn down (destorying all threads).

Which makes the most upvoted answer dangerous, as it teaches you how to affect the recycle process, without controlling the tear-downs (off app-domains and threads) that IIS itself will intermittenly perform.

The requester is "foreign" to the IIS itself.

The internal lifetime of the service though, is entirely managed by IIS (and the configuration of its applications) itself.

So if with "keep alive" you mean: to constantly request some service, then do as Andreas suggest further up (create a schedueled job).

If with "keep alive" you mean: to make sure the same instance of the class handles requests, then you need to look into WCF lifetimes.

If with "keep alive" you mean: to make the code you have created "stateful" and keep f.eks static variables alive and so on, well you are not accepting that IIS is basically a stateless pr. request broker with internal lifetime management.

Upvotes: 2

Manish Jain
Manish Jain

Reputation: 9649

Go to your IIS -> Application Pool (or create new one) -> Advanced settings and set Regular Time Interval=0

enter image description here

See related thread here.

Upvotes: 9

Andreas Warberg
Andreas Warberg

Reputation: 640

I suggest you create a small program (console app) that calls the web service. The program should take as arguments the url of the web service. Then you create a windows scheduled task that runs the program. In this way you have a lot of flexibility as compared to the embedded approach you are querying about as the program is just another client to the web service.

Upvotes: 2

NDJ
NDJ

Reputation: 5194

AppFabric allows you to create wcf services which can autostart and be long living - this might be worth checking out as a hosting option (it's just a plugin for IIS)

Auto Start

Upvotes: 5

Łukasz Adamus
Łukasz Adamus

Reputation: 266

Try to avoid using while loop. Maybe http://quartznet.sourceforge.net/ is something you are looking for. On WCF start create Task every 10 minutes which will cal WCF itself.

Upvotes: 1

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