Microsoft Sharepoint Products and Technologies Resource Kit eBook

114 Part II: SharePoint Products and Technologies Architecture
Building on Windows SharePoint Services
Windows SharePoint Services is required when installing SharePoint Portal Server.
SharePoint Portal Server can install over an existing Windows SharePoint Services
installation, or if Windows SharePoint Services is not yet installed, SharePoint Portal
Server installs Windows SharePoint Services first as part of the installation process.
Additional Services
SharePoint Portal Server includes services that are not offered in Windows Share-
Point Services. These services can be viewed in the Services application in Control
Panel and include the Administration service, the SharePoint Portal Alert service, the
Microsoft SharePoint Portal Server Search service, and the Microsoft Single Sign-On
service.
Administration Service
Note During installation, all services that SharePoint Portal Server can
provide are installed regardless of which services you choose to install. The
services are then enabled or disabled based on which services the administrator
chooses to provide to users.
SharePoint Portal Server installs an administration service, called SharePoint Portal
Administration, that appears as SPSAdmin in the Services application in Control
Panel. SPSAdmin can stop and start services that SharePoint Portal Server needs,
including SPSSearch. It can also add or delete catalogs and can add or delete search
applications as needed.
SPSAdmin is a service that was written to maintain the configuration of each
server in a SharePoint Portal Server deployment. Essentially, this service runs on
each server in the farm and is responsible for checking the configuration database
every 30 seconds to ensure that the local server is performing its assigned roles.
In the SharePoint Portal Server Central Administration/Component Selection
area, each server in the farm must be assigned at least one role to perform in the
farm. When a role is assigned to a server in the farm, it is recorded in the configuration
database. The SharePoint Portal Administration service checks this database
every 30 seconds to ensure that the server is performing its assigned role or roles. If
the service discovers that there is a modification in the server’s roles, the service will
“turn on” or “turn off” those portions of the server’s code to either stop performing
a role or to start performing a role.
For example, let’s assume that there are six front-end Web servers in a large
farm. Now let’s assume that server1, a front-end Web server, is a search server. This