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DevForce Resource Center » Development guide » Configure and deploy » Customize startup and shutdown
Last modified on August 15, 2012 17:20
Regardless of whether your application is a two-tier application performing its own persistence operations, or an n-tier application with a separate application server tier, you might have the need to do some custom processing when the singleton EntityService starts up and again when it shuts down.
What is the EntityService
We don't often mention the EntityService when discussing the application server tier, but you've likely seen the name used throughout these pages. You've seen it in the <objectServer> element in your config file. You'll see it when you customize WCF configuration with a <serviceModel> definition.
The EntityService functions as little more than a gateway or simple router: its primary purpose is to inform a requesting client which EntityServer it will be working with, and to either start that EntityServer or ensure it's already running. It's the EntityServer which is responsible for all persistence and security activities. These actions occur whether the application is a standalone application communicating directly with the data tier, or the EntityServer has been deployed to an application server tier.
The EntityServiceApplication
The IdeaBlade.EntityModel.EntityServiceApplication allows a developer to inject custom logic when the EntityService starts, and again at shut down.
Here's a sample implementation:
| C# | public class CustomEntityServiceApplication : EntityServiceApplication { public override void OnServiceStartup(object sender, ServiceStartupEventArgs e) { base.OnServiceStartup(sender, e); IdeaBlade.Core.TraceFns.WriteLine("My custom EntityServiceApplication is starting."); } public override void OnServiceShutdown(object sender, EventArgs e) { IdeaBlade.Core.TraceFns.WriteLine("My custom EntityServiceApplication is stopping."); base.OnServiceShutdown(sender, e); } } |
Your custom EntityServiceApplication is found during standard discovery.
At startup, your application might need to launch auxiliary "server-side" processes for example, or perform other one-time actions.
At shutdown, the application can run "server-side" clean-up code. For example, it might shut down the auxiliary services it started or send an email alert reporting that the service is coming down.