Having recently worked on integrating across multiple CICS regions using CTG, I have shared some of my observations during configuration.To put things in perspective, below is a conceptual diagram to set up a high availability CTG environment.
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Before you start:
1.CICS Transaction Gateway should be installed.
2.You also need to install support pack CA1T V3.0.1.
3.Each CICS region needs to have dedicated IPIC enabled TCP/IP listener port.
Also note, a single instance of CTG cannot connect using a shared TCPIP port across multiple CICS regions. In order to establish a CTG connectivity, it needs a dedicated IPIC enabled port that the CICS region is configured to listen on. There seems to be a limitation on CTG to connect to multiple CICS regions with any available ports. Some of the available protocols on TCPIP ports are ECI,HTTP,IPIC.
Here are the steps: Step 1:Make the following entries in the ctg.ini file With the known CTG regions that you need to connect that has the dedicated IPIC ports, include the CTG configuration details in the format below SECTION IPICSERVER = IPIC1 HOSTNAME=Hostname / ip address PORT=IPIC PortNumber ENDSECTION SECTION IPICSERVER = IPIC2 HOSTNAME=Hostname / ip address PORT= IPIC PortNumber ENDSECTION
Step 2: Enable Load balancing feature. Load balancing(round-robin)is enabled by setting following property in CTG configuration file cicsrequestexit=com.ibm.ctg.samples.ha.RoundRobinExit
Step 3:Next, set list of available IPIC connections to the load balancing pool. This will be part of ctg.ha.ini file. CTG_LBG=IPIC1, IPIC2
Step 4:Finally, bind web service to load balancing group SECTION WEBSERVICE=getmyaddress URI=/getmyaddrdetails/v1 BINDFILE=~/home/apps/GET_CUST_ADDR_DETAILS/GET_CUST_ADDR_DETAILS.wsbind SERVER= CTG_LBG ENDSECTION