The Service Application Framework provides a platform that allows
developers to build scalable applications that are hosted in SharePoint 2010.
These services can provide data or processing resources to other SharePoint
features. The Service Application Framework enables services to be shared
between computers on a server farm; it also helps load manages the services in
SharePoint. The Service Application Framework provides over 20 services that are
built into the core product.. The Service Application Framework is an API that
is provided to build services that are hosted by back-end application servers
and consumed by front-end Web servers. The Service Application Framework
replaces the Shared Services Provider in Microsoft Office SharePoint Server
2007. The Service Application Framework model is much more flexible than the
Shared Services Provider model. Service applications can be used by a single
server farm or shared across farms, allowing centralized shared computing
investments. Service Application Framework applications are easily scaled out
for load balancing high-demand service applications.
Reasons to
use the Service Application Framework include the following:
1. To provide specialized computations and analytics that are
consumable by multiple SharePoint Web applications
2. To share data across sites and site collections, providing
multiple instances of your application in a farm for hosting scenarios
3. To execute long-running operations
4. To use the common management and provisioning infrastructure
provided by the Service Application Framework
In order to use a Shared Service, a Service Application must be
provisioned. A Service Application is a farm level instance, "logical instance",
of a Shared Service. A Service Application consists of the following:
1.
Administrative interface
2.
Application Pool
3. Databases
4. Physical Instance
As I mentioned above not all Service Applications are the same.
Each one is unique and may or may not contain the above components listed. For
Example: SharePoint OOB comes with Excel Shared Service. Until you deploy and
create a service application, you cannot consume that shared service. Service
Applications can be provisioned automatically using the Farm Configuration
Wizard or manually by using Central Administrator\Manage Service Application
page. Power Shell can also be used to create Service Applications.
Redundancy Built-in
As you know
multiple application servers can run a physical instance of the same Service
Application. This provides redundancy in that requests from WFE's pass through a
built in load balancer to locate available application server running a physical
instance.
Load Balancing
It uses Use
Round robbing load balancing Service application proxy method invocations must
be routed thru the front end web server to an appropriate app server by using a
load balancing tool. Calls between front-end and app servers to require separate
external load balancer than the load balancing for front-end web servers
Management
and Administration
Services plug their
management UI into SharePoint Service Management page. This has a Common admin
tools such as upgrade, backup, restore and account management .Common UI to
manage, start, stop, group, associate, federate and backup SharePoint services.
It can define specialized admin roles and can be delegated
to users who are not farm admins.