Does a WCF self hosted service handle more or less load than the IIS hosted option?

Question

Does the hosting option affects the amount of requests a WCF service can handle?

Answer 1

Hard to say - the main reason for self-hosting is probably having more control, e.g. being able to tweak the system as you need it.

IIS hosting is convenient and easy to set up, and it offers "on-demand" loading of the service, e.g. the service host is only loaded if a request actually comes in.

This constant loading (and unloading) of the service host will probably hurt performance a little bit - on the other hand, self-hosting a service host, you probably use more memory (since the ServiceHost is active and in memory at all times).

So again - it's a memory-vs-speed trade-off - selfhosting uses more RAM but is probably a tiny bit faster.

Marc

Answer 2

Once the service is running I would expect no significant difference.

But, as with any performance question, you can only get a useful answer by testing your service in both cases with realistic loads and looking at the big picture. E.g. one might server a few more requests but at a slightly higher memory cost.

There are of course going to be other differences e.g. IIS hosting, with on demand instantiation, would be expected to be a little slower to serve the first request from idle, whether this is significant only you can tell.

Answer 3

Once "Dublin" (a purpose built WCF hosting environment) is released, it will be natural to use that.

EDIT: This answer was originally about the potential difference between IIS and self hosted due to differences in threading. However, I stand corrected, see the comment below.