Datasheet

SQLServerAgent (SQL Server Agent)

This service is responsible for the execution of scheduled jobs such as scheduled backups, import/export

jobs, and Integration Services packages. If any scheduled tasks require network or file system access, the

SQLServerAgent service’s credentials are typically used.

The

SQLServerAgent service is dependent on the MSSQLServer service. During installation, the option

is given to configure both services with the same credentials. Although this is by no means required, it is

common practice. A frequent problem encountered by database administrators is that jobs that work

perfectly when run manually fail when run by the agent. The reason for the failure is because the

account that is used when testing the job manually is the logged-in administrator, but when the job is

executed by the agent, the account the agent is running under does not have adequate permissions.

MSSQLServerADHelper (SQL Server Active Director Helper)

Very often, the MSSQLServer service and the SQLServerAgent service are configured to run with a

domain account that has local administrative rights on the server SQL Server is installed on. Although

this configuration offers a great deal of flexibility to what the two services can do locally, it doesn’t give

them any permission to Active Directory.

In order for the

MSSQLServer service to register its respective instance of SQL Server, it must be either

running as the local system account (which significantly reduces the flexibility of the service), or be a

member of the domain admin group (which grants it way too much access, violating the principle of

least privilege).

To enable SQL Server to register itself in the domain, but not limit its functionality, the

MSSQLServerADHelper service was created. The MSSQLServerADHelper service runs under the local

system account of the domain computer SQL Server is installed on, and is automatically granted the

right to add and remove objects from Active Directory. The

MSSQLServerADHelper service only runs

when needed to access Active Directory and is started by the

MSSQLServer service when required.

Regardless of the number of installed instances there is only one

MSSQLServerADHelper service per

computer.

MSSQLServerOLAPService (SQL Server Analysis Services)

MSSQLServerOLAPService is the service that Analysis Services runs under. Analysis Services provides

the services and functionality to support all of SQL Server 2005’s OLAP needs, as well as the new data

mining engine included with SQL Server 2005.

SQLBrowser (SQL Server Browser)

The SQLBrowser service is used by SQL Server for named instance name resolution and server name

enumeration over TCP/IP and VIA networks.

The default instance of SQL Server is assigned the TCP port 1433 by default to support client communi-

cation. However, because more than one application cannot share a port assignment, any named

instances are given a random port number when the service is started. This random port assignment

makes it difficult for clients to connect to it, because the client applications don’t know what port the

server is listening on. To meet this need, the

SQLBrowser service was created.

Chapter 1

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