Installing system links using the WUI

When you install a system link, you are establishing a connection between two CICS regions that are managed by CICSPlex SM. The definitions referred to by that system link are installed in the target CICS® regions.

Before you begin

You must have defined the required connection objects, as described in Defining connections between CICS regions.

About this task

You can install system links automatically at CICS initialization by specifying the ALWAYS attribute in the Install BAS resources option field of the CICS system definition. You can also install system links dynamically while a CICS region is active using the CICS Explorer® or Web User Interface. The following procedure describes how to install system links dynamically using the WUI.

Procedure

  1. From the main menu, click Administration > Basic CICS resource administration > CICS system links and related resources.
  2. Select the appropriate link to display all SYSLINK objects or filter by connection type.
  3. Select the check box next to the SYSLINK that you want to install and click the Install button to open an Install input panel.
  4. Fill out the fields in the input panel to select the checks that CICSPlex SM will run before installing the resources:
    1. Select the type of checking to be performed before attempting to install resources in the CICS regions associated with the description.
    2. Select whether the existence and operational state of all resources are to be checked before an EXEC CICS CREATE command is issued.
    3. Select whether you want CICSPlex SM to force the installation of the resources.
      CICSPlex SM checks to see if it installed the current resource in the CICS region. If it is installed, CICSPlex SM does not install the resource, to avoid changing the attributes of an active resource.
  5. Click Yes to install the system link in the active CICS regions.

Results

CICSPlex SM creates and installs the resource definitions into the specified target CICS regions to create the connection. Some of the values are altered in the target regions by the installation process.
  • For an MRO or IPIC connection, the Receive count is swapped with the Send count and the Receive size is swapped with the Send size on the CONNDEF or IPCONDEF resource objects.
  • For an APPC connection, the Receive size field is swapped with the Send size and the Maximum number of sessions supported as contention winners is recalculated by subtracting the 'Maximum number of sessions supported as contention winners' from the Maximum number of sessions in the group in the primary CICS region.

For IPIC connections, the TCPDEF resource object installs first followed by the IPCONDEF. If a TCPDEF resource object of the same name and port number is already installed and is in the OPEN state, CICSPlex SM does not attempt to reinstall the resource object. Some of the values are altered in the definitions for both the primary and secondary regions:

  • The URM value is always set to NO when the TCPDEF resource object is installed.
  • If a network ID is specified in the system definition of the secondary region, it overrides the value of the network ID in the IPIC connection definition of the primary region.
  • If a host or port number is specified in the system definition of the secondary region, it overrides the value of the host and port number in the IPIC connection definition of the primary region.
  • An IPIC connection definition on the secondary region inherits the host and port number from the TCPDEF resource object.
  • If the host and port number are specified in the system definition of the primary or secondary region, these values override the values in the TCPDEF resource object for that region. If the TCPDEF resource object is installing on the secondary region, the host and port number are taken from the IPCONDEF definition on the primary region.

What to do next

You can verify that the connection is active by looking at the installed resources on the pair of CICS regions.