Update data response

When the ongoing snapshot action has been issued and is currently in effect, updates to the luCollection object results in the sending of a snapshot linked reply with the update. In this case, only data pertinent to the subject LU flows in the snapshot linked reply. In general, updates for luCollection (Host) are caused by the activation or inactivation of a major node containing LU or CDRSC definitions or a state change of these resources. Creation or deletion of USERVARs and generic resources also cause updates.

Table 1. Resources with reason for luCollection (host) update data
Resource	Reason	Notes
Non-SNA LU or application program	Creation	Major node activation. Model application ignored.
	Deletion	Major node inactivation. Model application ignored.
	State change	Resource changed state. Model application ignored.
CDRSC	Creation	Dynamic alias ignored. Model CDRSC ignored.
	Deletion	Dynamic alias ignored. Model CDRSC ignored.
	State change	Resource changed state. Model CDRSC ignored.
	Attribute value change	CDRSC has a new owning CDRM. Model CDRSC ignored.
LU Group	Creation	USERVAR or generic resource created
	Deletion	USERVAR or generic resource deleted
	State change	Not applicable
	Attribute value change (member added or member deleted)	Not supported for this snapshot

Updates for luCollection (PU) are generally caused by state changes of dependent LUs defined under a monitored PU. Also, creation or deletion of dynamic dependent LUs as well as connection of independent LUs using the PU as an adjacent link station (ALS) will result in updates.

Table 2. Resources with reason for luCollection (PU) update data
Resource	Reason	Notes
Dependent LU	Creation	Dynamic LU created
	Deletion	Dynamic LU deleted
	State change	Dependent LU changed state
Independent LU	Creation	New session through adjacent link station
	Deletion	End last session through adjacent link station
	State change	Not reported

Updates for the luCollection object can be merged with related updates by the VTAM topology agent before being written to the snapshot linked replies.

A snapshot luUCollection is automatically cancelled when the PU supporting the luCollection is deleted. luCollection updates are not merged when they are the result of a VTAM-cancelled luCollection.

Some updates for luCollection snapshots might be reported under more than one luCollection. For example, some updates, such as updates for independent LUs, might be reported under several monitored PUs and also under the VTAM® host. All VTAM host luCollection updates are merged, but updates for a specific PU are not merged if the updates represent independent LUs.

Updates that report a deleted object are not merged.