Address spaces

There are different types of address spaces that come with z/Server:

• Holder address space (STC).
• One or more STC scheduler address spaces (STC).
• One or more STC user server address spaces per TSO user/ Eclipse client (STC).

If you want to use the CEA-launched address space you will also need the following address spaces:

• One or more CEA scheduler address spaces (STC).
• One or more CEA user server address spaces per TSO user/Eclipse client (TSO address space).

They need an associated user ID:

• STC scheduler and holder always use the assigned user ID.
• STC user servers start out with the assigned user ID, which is then switched to the user ID of the client that requested execution of some application via TCPIP and started them.

If you want to use the CEA-launched address space you will also need the following:

• CEA schedulers always use the assigned user ID.
• CEA user servers are started with the TSO user ID of the client.

The holder address space is responsible for starting and stopping schedulers, which in turn start user servers. Because of this, the holder address space does not need to have any ports allocated to it.

The scheduler address space defines a LISTENER_PORT that listens for incoming requests from the client, and a further port range (defined by FIRST_PORT through LAST_PORT) that will be assigned to different user servers as required. The combination of ports specified by the scheduler (both LISTENER_PORT and the range specified by FIRST_PORT through LAST_PORT) must be opened in the firewall protecting the z/OS host system. These ports should not be assigned to the scheduler. Instead, if desired, an appropriate RACF profile in the SERVAUTH needs to be defined. Please refer to IBM's TCPIP documentation. The default port range specified by the configuration file that comes with z/Server is 1200 to 1249.

User servers use the port assigned to them by the scheduler, to listen for incoming requests.