Autoinstalling APPC connections

When you decide whether to use autoinstall for connections, there are several factors to consider.

Security
Before using autoinstall for connections, consider whether the security considerations are suitable for your purposes.
The autoinstalled connection inherits the security attributes specified in the model. The security attributes from the CONNECTION definition are:
  • SECURITYNAME
  • ATTACHSEC
  • BINDSECURITY

If you are using compatibility mode to share a CSD file with an earlier release of CICS®, the BINDPASSWORD attribute is also inherited. See SESSIONS attributes for information on these attributes.

From the SESSIONS definition, the autoinstalled connection inherits the preset security attribute USERID. If you are attempting to autoinstall an attachsec verify connection from a non-EBCDIC based system, then you should refer to Bind-time security with LU6.2

Model terminal support (MTS)
MTS is not supported for connection autoinstall. This means that you must code the routines yourself to select the model definition name; you cannot get z/OS® Communications Server to do it for you. MTS is described in Autoinstall and z/OS Communications Server.
Deletion of autoinstalled connections
Unlike autoinstalled terminal definitions, autoinstalled connection definitions are not deleted when they are no longer in use. This means that they continue to occupy storage.

The rules for cataloging and deletion of autoinstalled APPC connections have changed in CICS Transaction Server for z/OS. All autoinstalled connections are now cataloged, depending on the AIRDELAY system initialization parameter. If AIRDELAY=0, synclevel 1 connections are not cataloged.

The rules for deletion are:
  • Autoinstalled synclevel 1 connections are deleted when they are released.
  • If CICS is not registered as a generic resource, autoinstalled synclevel 2 connections are not deleted.
  • If CICS is registered as a generic resource, autoinstalled synclevel 2 and limited resources connections are deleted when the affinity is ended.

If autoinstall is enabled, and an APPC BIND request is received for an APPC service manager (SNASVCMG) session that does not have a matching CICS CONNECTION definition, or a BIND is received for a single session, a new connection is created and installed automatically.