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