This appendix presents a sample CA IDMS DDS configuration that uses TCP/IP to connect two CA IDMS nodes residing in different machines. The next section illustrates the CA IDMS system generation statements needed to run in a CA IDMS DDS environment.
A pool of free connections (socket connections) can be maintained between the two CA IDMS nodes. This pool of connection is controlled by the local system. The free connections in the pool can belong to the following lists:
The maximum number of free connections that can belong to that list is defined using the PERMANENT CONNECTION clause on the DDSTCPIP type PTERM sysgen statement. These connections are not pre-allocated when the corresponding DDSTCPIP PTERM is varied online in the local system, but only when a DDS request completes.
The amount of time a free connection remains in the idle list is defined using the IDLE INTERVAL clause on the DDSTCPIP type PTERM sysgen statement.
When a DDS request is started, the system tries to find a free connection from the pool of connections, and if one is present (scans first the idle list, then in the permanent list), it assigns it to the request. If no free connection is found, it creates a new one to serve the request.
When the DDS request terminates, the corresponding connection is either returned to the pool of connections (in the permanent list first, if the maximum number of permanent connections in the pool is not reached yet, or in the idle list, if it applies), or simply closed.
A special connection, called the control connection, is always maintained between the two nodes and is reserved by the system to detect when one of the nodes abends or stop normally.
|
Copyright © 2013 CA.
All rights reserved.
|
|