SQL network entities
Overview
This overview topic introduces the network entities that you define to establish Model 204 TCP/IP (Horizon) networks:
- Link
- Processgroup
- Process
Definitions that you provide for these entities set the physical and logical characteristics of network conversations. For detailed information on defining these entities, see the Rocket Model 204 documentation wiki command pages:
DEFINE LINK command: Horizon for TCP/IP
DEFINE PROCESS command: Horizon for TCP/IP and VTAM
DEFINE PROCESSGROUP command: Horizon for TCP/IP
Link
A link represents a connection between Model 204 and a network. The link definition specifies the transport mechanism and protocol to use for communications.
Processgroup
A processgroup connects one or more processes to a specific link, and groups processes according to certain attributes to facilitate resource allocation. The processgroup definition also specifies the remote partner with which the processes can communicate.
Process
The process definition associates the CCARSQL process (the Model 204 SQL process) with one or more processgroups; the processgroup(s) associate the process with one or more links.
CCARSQL always receives the SQL client's request for a conversation. This same CCARSQL process is used for all connections to the Model 204 SQL Server:one definition of CCARSQL must apply to all SQL and RCL connections.
Defining connections
If you are running SQL or RCL on a PC or workstation using 32-bit Connect★, define a connection for Model 204 TCP/IP (Horizon).
For more information, see Horizon TCP/IP.
Single and multiple definitions
For Connect★, specify DEFINE commands for each of the SQL network entities: link, processgroup, and process.
See the excerpt from the sample Model 204 Online job in Runtime examples.
Where to specify DEFINE commands
The DEFINE commands can be:
- Coded in the CCAIN stream of the job or EXEC you use to bring up your Model 204 Online
- Stored in a SOUL procedure that is invoked by the Online at runtime
- Issued Online from Model 204 command level by a user with system manager privileges
Network control commands
Use network control commands to manipulate the Model 204 TCP/IP (Horizon) network entities (link, processgroup, and process) once you have defined them.
You can place these commands in the User 0 stream or in a Model 204 procedure, or issue them at command level. You must have User 0, system administrator, or system manager privileges.
These commands are listed in the following table. For details, follow the links in the table.
Network control commands
| Command | Function |
|---|---|
| OPEN LINK name | Opens the link; required for connection |
| CLOSE LINK name | Disables an opened link |
| START type name | Starts a stopped link or processgroup |
| STOP type name | Stops a link or processgroup |
| MONITOR type name | Displays current usage of a network entity |
| MODIFY PROCESSGROUP name | Modifies a current processgroup definition |