Starting the Distributed Data Server

The Distributed Data Server (DDS) provides the ability to serve multiple clients in a single-server address space. This capability is used, for example, by RMF™ PM.

To have the Distributed Data Server address space managed by RMF, you can start it automatically by using the DDS option. This option ensures that you always have one active instance of the Distributed Data Server within your sysplex. As soon as the RMF Sysplex Data Server recognizes the DDS option on any system in the sysplex, the Distributed Data Server is started on the RMF master system. The master system is a system with an active Monitor III gatherer, the highest z/OS release and SMFBUF option set. The MASTER parmlib option can be used to define a system to be a master system candidate. If another system becomes the master system, the Distributed Data Server is automatically restarted on this system.

You can specify the DDS option as follows:

PARM='DDS': to activate the sysplex-wide DDS management with the EXEC statement of the RMF procedure (see Customizing the RMF control session).
S RMF,,,DDS: to activate the sysplex-wide DDS management with the RMF start command.
F RMF,DDS: to activate the sysplex-wide DDS management with the RMF modify command.

You can stop the syspley-wide DDS management using the NODDS option. For example, the command F RMF,NODDS also shuts down the current sysplex-wide DDS instance, regardless on which system the command has been entered.

Example for manual startup of GPMSERVE: To start the Distributed Data Server manually, assuming that you have stored the corresponding parameters in Parmlib member GPMSRV01, issue the command:

S GPMSERVE,MEMBER=01

If you use the default member GPMSRV00, you can omit the MEMBER parameter.

To retrieve information about an automatically started Distributed Data Server, you can use the following commands:

MODIFY RMFDDS01,OPTIONS shows the currently active GPMSERVE options.
 
MODIFY RMFDDS01,DISPLAY shows the currently active connections.

Note:

If you started the Distributed Data Server address space manually, use GPMSERVE instead of RMFDDS01 as identifier in the commands.
You must restart the DDS to ensure correct operation when the local time changed (daylight saving time).