Umbraco 7.3 - Enable DatabaseServerMessenger

gistfile1.cs

public class LoadBalancingConfigurationEventHandler : ApplicationEventHandler
{
	protected override void ApplicationStarting(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
	{
		//Replace the server messenger:

		ServerMessengerResolver.Current.SetServerMessenger(new BatchedDatabaseServerMessenger(
			applicationContext,
			true,
			//You can customize some options by setting the options parameters here:
			new DatabaseServerMessengerOptions
			{
				//These callbacks will be executed if the server has not been synced
				// (i.e. it is a new server or the lastsynced.txt file has been removed)
				InitializingCallbacks = new Action[]
				{
					//rebuild the xml cache file if the server is not synced
					() => global::umbraco.content.Instance.RefreshContentFromDatabase(),
					//rebuild indexes if the server is not synced
					// NOTE: This will rebuild ALL indexes including the members, if developers want to target specific 
					// indexes then they can adjust this logic themselves.
					() => Examine.ExamineManager.Instance.RebuildIndex()
				}
			}));

		//Replace the server registrar (this is optional but allows you to track active servers participating
		// in your load balanced environment):

		ServerRegistrarResolver.Current.SetServerRegistrar(new DatabaseServerRegistrar(
			new Lazy<ServerRegistrationService>(() => applicationContext.Services.ServerRegistrationService),
			//You can customize some options by setting the options parameters here:
			new DatabaseServerRegistrarOptions()));
	}
}