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Background documentation X Server Locate the document in its SAP Library structure

The X Server is the communication instance of the database software. It is mostly required if the individual software components are on different hosts: Database applications and database tools communicate with a database instance installed on a remote host using the X Server that also runs on the remote host (see also Architecture of the Database Manager and Architecture of the Loader).

On UNIX operating systems, the X Server is also used to allow communication with the DBM Server within a host.

Note

SQL connections on UNIX systems and all connections within hosts under Microsoft Windows use Shared Memory. If you still want to force the use of the X Server, specify the option –n localhost when connecting to the database instance.

Prerequisites for Communication

The following prerequisites must be fulfilled to allow communication through the X Server:

·        On Microsoft Windows operating systems, the X Server is registered as the system service XServer. This service must be active. An additional thread within the X Server process is created with every successful connection through the X Server.

·        On UNIX operating systems, the X Server must be running in the background as the process vserver. An additional child process is started for every successful connection through the X Server.

Starting and Stopping the X Server

x_server [<option>] start|stop

You can specify the following options when you call the X Server:

Option

Explanation

-Y

Suppresses the communication through the NI server, which is only relevant for SAP Support

-F

Suppresses the determination of DNS entries, which speeds up connections

-S <service|port>

Specifies an alternative list port

 

 

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