How To Limit a WCF Service Application, So That Only Unique Clients Can Access

Question

i have a wcf service in c# (like the calculatorservice from msdn examples), and i was wondering is it possilble to limit it to serve only 1 client per IP?

i want the possibility of a few IPs to be connected at once (at least 5-6 active sessions), and that works for now, but i don't want more than 1 connection per unique IP (or unique computer)

Answer 1

You might want to have a look at the service throttling options on the service behavior,

e.g

<behavior name="throttled">
  <serviceThrottling 
    maxConcurrentCalls="10"     // # of messages the host can process (default = 10)
    maxConcurrentInstances="1"  // # of host instances
    maxConcurrentSessions="16"  // # of host sessions (default = 16)
    />
</behavior>

http://www.michaelflanakin.com/Weblog/tabid/142/articleType/ArticleView/articleId/904/WCF-Service-Throttling.aspx

Answer 2

If you need 5 opened sessions at one time and you are saying that maxConcurrentInstances causes only 1 usuable client, have you set the InstanceContextMode to = PerSession? You most likely have it set to Single, in that case maxConcurrentCalls has no effect. Change it to PerSession and the throttling config ForeverDebugging has shown will work.

Answer 3

i made some progress. when the client invokes the service for the first time, in the constructor i save his ip address and his current operation context.

then, if someone from the same ip connects, i abort the previous channel that that ip address used (newest connection has the priority):

operationContext.Channel.Abort();

i tested it, and it appears to free up the session so others can use it, but i am not sure -- is this the best solution?