CICS Transaction Server for z/OS three-tier connectivity
The CICSRequest node support in IBM® Integration Bus can provide communication with CICS® Transaction Server for z/OS® through CICS TG (three-tier connection).
The CICSRequest node also supports direct communication with CICS (two-tier connection) by sending Distributed Program Link (DPL) requests over TCP/IP-based IP InterCommunications (IPIC) protocol. For more information about two-tier connections, see CICS Transaction Server for z/OS two-tier connectivity.
A three-tier connection from IBM Integration Bus to CICS through CICS TG can be made by configuring the cicsServer and gatewayURL CICSConnection configurable service properties.
For more information about configuring the cicsServer and gatewayURL CICSConnection configurable service properties to make a three-tier connection, see Configurable services properties.
The three-tier connection to CICS through CICS TG connection model is based on the following rules:
- The number of connections that can be made to CICS TG is determined by the maximum number of simultaneous CICS requests in progress. Ensure that the Connection Manager and Worker Thread resources in your CICS TG deployment have sufficient capacity to handle the number of required IBM Integration Bus connections.
- The clientApplid and clientQualifier properties in the CICSConnection configurable service can be used to identify the integration node connection within CICS TG. In addition, any CICS tasks that are started through the configurable service each contain point of origin information, including the specified client APPLID and qualifier, which you can find in the CICS task association data.
- Unlike two-tier connections, there is no restriction about sharing client APPLIDs between integration servers because the connection is made to CICS TG, and not to CICS directly.
For more information about configuring the CICSRequest node to get connection details from a CICSConnection configurable service, see Changing connection information for the CICSRequest node.