Deployment of SQL-NS Instances on Multiple Servers


The deployment of a SQL-NS instance can span multiple servers. The instance database and the SQL-NS engine do not need to be located on the same server (although they certainly can be, if that suits your deployment). Figure 4.7 shows various deployment configurations, including some on which the database and the SQL-NS engine are on different servers.

Figure 4.7. Various SQL-NS instance deployments across servers.


The split of SQL Server and the SQL-NS engine onto two separate machines is common. Many organizations share their SQL Server among many applications and like to keep the database server dedicated only to hosting databases. Also, this is a convenient split of resources for the way SQL-NS tends to operate. In many SQL-NS applications, about half the work tends to be done in the database (matching events and subscriptions), and the other half done in the SQL-NS Service (formatting and delivering notifications).

There are still more possibilities for deploying the instance on multiple servers if you are using the Enterprise Edition of SQL-NS. With Enterprise Edition, the various running components of each application can be configured to run on different servers. In other words, you can configure the event providers, the generator, and the distributors of a given application all to run on separate servers. Or you can have all the components for one application run on one server, and all the components for another application on a separate server. They are all still part of the same instance, but the deployment is spread out. Each server running application components runs its own copy of the SQL-NS service, and that service just hosts the components configured to run on that machine. Chapter 13 describes the various deployment options in detail. If you are running the Standard Edition of SQL-NS, all running components of the instance must be on the same machine, although the SQL Server can be on a separate machine.

SQL-NS Instances and SQL Server Instances

If you've worked with instances in SQL Server, the basic instance concept should be familiar. SQL Server lets you also create independent, named configurations and calls these instances. SQL Server instances do not necessarily map 1:1 to SQL-NS instances.

A single SQL Server instance may host databases from several SQL-NS instances. However, a single SQL-NS instance stores all its data on a single SQL Server instance.





Microsoft SQL Server 2005 Notification Services
Microsoft SQL Server 2005 Notification Services
ISBN: 0672327791
EAN: 2147483647
Year: 2006
Pages: 166
Authors: Shyam Pather

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