The X Server is the communication server of the database system. It listens at service port sql6/TCP for connection requests from database applications and database tools.
If a database application or a database tool wants to communicate with a database instance on a remote computer, then the connection is made through the X Server that is running on this remote computer.
The X Server is a cross-instance server: even if more than one database instance is running on a computer, only one X Server runs.
On UNIX operating systems, the X Server is also used to allow communication with the DBM Server within a computer.
SQL connections on UNIX systems and all connections within computers on 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.
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.
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 service port at which the X Server can listen |
See also:
· Architecture of the Database Manager