Rules for multiple definition of resources

The connection of an independent LU (CDRSC) to an adjacent link station is only for the duration of the independent LU's sessions. In addition, the independent LU can have multiple concurrent sessions using different adjacent link stations.

The rules for multiple definition of resources are presented in Table 1. This table assumes that a CDRSC is currently defined to VTAM® (existing resource). It also assumes that the operator issues a command to activate a major node that contains new definition statements (input resource). Multiple definition of resources occurs when the name of an input resource matches the name of an existing resource.

Table 1. Rules for multiple definition of resources
Existing resource	Input resource	Major node after integration	Notes
Dynamic CDRSC	Dynamic CDRSC	Not applicable	1
Dynamic CDRSC	Predefined Independent LU	ISTPDILU	2, 5
Dynamic CDRSC	Predefined CDRSC	CDRSC major node	2, 5
Predefined Independent LU	Dynamic CDRSC	Not applicable	1
Predefined Independent LU	Predefined Independent LU	Not applicable	4
Predefined Independent LU	Predefined CDRSC	ISTPDILU	2, 6
Predefined CDRSC	Dynamic CDRSC	Not applicable	1
Predefined CDRSC	Predefined Independent LU	ISTPDILU	3, 7
Predefined CDRSC	Predefined CDRSC	Not applicable	4
Predefined APPL	Predefined CDRSC	CDRSC major node	5
Predefined LU	Predefined CDRSC	CDRSC major node	5
MNPS application	Predefined CDRSC	Not applicable	8

Note:

This case does not apply to multiple definition of resources. When a resource currently exists, no new dynamic CDRSC is created or considered.
If the two resource definitions have different NETID values, both are specified with NQNMODE=NAME, either by definition or start option, and the existing resource has active or pending sessions, the input resource is not defined to VTAM. If the existing resource does not have any sessions, the input resource's NETID value is also the resulting resource's NETID value.
If the two resource definitions have different NETID values and at least one is specified with NQNMODE=NQNAME, either by definition or start option, the resource definitions are not merged.
If the two resource definitions have different NETID values and both are specified with NQNMODE=NAME, either by definition or start option, the input resource is not defined to VTAM. This is true whether the existing resource has sessions or not. If the NETID values of the two resource definitions do not conflict, the input resource's NETID value is also the resulting resource's NETID value.
If the two resource definitions have different NETID values and at least one is specified with NQNMODE=NQNAME, either by definition or start option, the resource definitions are not merged.
If both are specified with NQNMODE=NAME, either by definition or start option, a duplicate definition of the resource occurs, and the input resource is not defined to VTAM.
If the two resource definitions have different NETID values and at least one is specified with NQNMODE=NQNAME, either by definition or start option, the resource definitions are not merged.
All operands from the input resource apply to the existing resource.
CDRSC operands from the input resource apply to the existing resource.
Only LU operands from the input resource apply to the existing resource.
Predefining a CDRSC at a network node will fail if an MNPS application is already active using the same name. IST489I is issued.

Exceptions to the merging of multiple resource definitions might occur. These exceptions occur because of different NETID values for the existing and new resource definition, which are both specified with NQNMODE=NAME (either by definition or start option). Changes in the NETID of a given resource can occur only if the resource does not have any existing or pending sessions.

If either the existing resource or the input resource is specified with NQNMODE=NQNAME and they have different NETID values, the resource definitions are not merged.

Merging multiple resource definitions causes operands from the input resource to overlay values in the existing resource only in cases where the operands of the existing resource are default values. Defined values on operands of the existing resource are not overlaid with default values on operands of the input resource. Default values and sifted values from the input resource apply to the existing resource definition as well, so long as they do not override defined values on operands of the existing resource. However, not all operands are necessarily integrated as a result of the second resource definition.

The method used for determining what operands to integrate from the input definition to the existing definition is as follows:

If the existing resource is a dynamic or predefined CDRSC and the input resource is a predefined independent LU, the following operands on the CDRSC definition statement are integrated:
- ASLENT
- ASLTAB
- DLOGMOD
- EAS
- ENCR
- ENCRTYPE
- LOGAPPL
- LUALIAS
- MDLENT
- MDLTAB
- MODETAB
- NETID
- PACING
- RESSCB
- VPACING
If the existing resource is a predefined independent LU and the input resource is a predefined CDRSC, the following operands on the CDRSC definition statement are integrated:
- ALSREQ
- CDRM
- ALSLIST ²
- LUALIAS ¹
- NETID
- NQNMODE ³
- VFYOWNER
If the existing resource is a predefined CDRSC, the input resource is a predefined CDRSC, they have different NETID values, and both are specified with NQNMODE=NAME, either by definition or start option, the second definition fails. (See note 2.)
If the two resource definitions have different NETID values and at least one is specified with NQNMODE=NQNAME, either by definition or start option, the resource definitions are not merged.
If the existing resource is a member of ISTPDILU, the input resource is a predefined independent LU, they have different NETID values, and both are specified with NQNMODE=NAME, either by definition or start option, all operands on the LU definition statement are integrated.
If the two resource definitions have different NETID values and at least one is specified with NQNMODE=NQNAME, either by definition or start option, the resource definitions are not merged.

When multiple resource definitions are merged, the resulting values for LUALIAS and NQNMODE are determined by several factors. The following tables show when LUALIAS and NQNMODE values are integrated.

¹ LUALIAS is only integrated in some cases. See Table 1.

² The list of adjacent link stations from the input resource and the existing resource are always combined.

³ NQNMODE is only integrated in some cases. See NQNMODE values after a merge of resource definitions.