Unity Child Container Lifetime with WCF

We're using Unity to provide dependency injection within the WCF service layer for our current project, and we have followed examples such as the following to write a service host factory, service host, service behaviour and instance provider:

http://avingtonsolutions.com/blog/post/2008/08/02/Uisng-Unity-with-a-WCF-Service.aspx

The solution works very successfully, but we have need to provide contextual resolution of objects on a per-request basis. So far, we have implemented this by creating a child container within the GetInstance method of the instance provider, adding the contextual registrations to the child container, and using the child container to perform the resolution of the service type. Some registrations in both containers use container controlled lifetimes.

As I do not know the lifetime of the child container, 开发者_高级运维I have concerns about this methodology: 1) Does the child container go out of scope at the end of the GetInstance method and therefore get disposed leading to some of our our container resolved objects being disposed in the middle of our request?

2) Alternatively, does the parent container cling on to the child container for some period of time meaning that it will rapidly fill with child container instances in a high traffic environment?

Can anyone point me in the right direction?