Can I tell WAS to start the new AppPool after a recycle?

Question

I have this administration site that is using (Fluent) NHibernate for data access. As has been stated elsewhere the initialization of the SessionFactory is slow due to creation of the Configuration object. The suggested solution is to serialize the Configuration object to disk and then reuse this untill the entity assembly or fluent initialization assembly changes.

In theory these sound very elegant and appealing. In practice even with a 1-entity model, deserializing the Configuration takes about 500ms and creating the SessionFactory another 500ms. (This is comparable to the startup time with no serialization, but I suspect the gain will be apparent once I put more entities in there.)

After IIS recycles my Application Pool, it doesn't start it up again untill a new request comes in. So with default recycle management of IIS (every 29h), and a probable scenario of an administrator logging into my administration site once a day, that 1s delay will happen almost every time this admin logs in, giving the impression of a slow starting site.

So, I wonder if there is any way to tell IIS/WAS to actually start the replacement Application Pool as part of the recycling instead of waiting untill the next request comes in? I realize this goes against the idea of WAS trying to keep as few concurrent application pools running at any given time, but it would solve my problem (as I assume my ServiceHostFactory+ServiceHost would be created as soon as the Application Pool starts up).

Answer 1

Will IIS 7 autostart feature help you? Also, you can implement System.Web.Hosting.IProcessHostPreloadClient interface to make sure the application is up when the pool is up (see this blog post for an example).