Browse Prior Art Database

Deferring Assignment of SNA LU 6.2 Logical Unit of Work Identifiers

IP.com Disclosure Number: IPCOM000037291D
Original Publication Date: 1989-Dec-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 3 page(s) / 49K

Publishing Venue

IBM

Related People

Coleman, A: AUTHOR [+5]

Abstract

Disclosed is part of the design of the SyncPoint Manager (SPM) portion of Coordinated Resource Recovery (CRR). CRR is a/VM implementation of the Systems Network Architecture (SNA) LU 6.2 Sync Point protocols [1]. The key feature of the design that is being disclosed is the deferral of the assignment of a SNA LU 6.2 architected Logical Unit of Work Identifier (LUWID) to a CMS work unit.

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Deferring Assignment of SNA LU 6.2 Logical Unit of Work Identifiers

Disclosed is part of the design of the SyncPoint Manager (SPM) portion of Coordinated Resource Recovery (CRR). CRR is a/VM implementation of the Systems Network Architecture (SNA) LU 6.2 Sync Point protocols [1]. The key feature of the design that is being disclosed is the deferral of the assignment of a SNA LU 6.2 architected Logical Unit of Work Identifier (LUWID) to a CMS work unit.

An application running under CMS uses CMS work units 2) to group its work. In VM/SP Release 6, only one resource could be updated on a work unit. A work unit was committed using private, non-syncpoint protocols.

With the introduction of CRR support, an application can update one or more resources on a single work unit in VM. All updates to the various resources for a work unit are committed at the same time with SNA LU 6.2 syncpoint protocols. Use of syncpoint protocols requires an LUWID, so CRR support associates an LUWID with a work unit.

A key requirement of LUWIDs is that they must be unique within the SNA network. The reason is that LUWIDs are used to group updates within the network, and there cannot by any ambiguity about which updates are related.

To fulfill the uniqueness requirement, CRR design creates LUWIDs in a separate virtual machine called the Recovery Processor. Because of this design, the decision was made to defer assignment of an LUWID to a work unit until it has been determined that a LUWID is needed for a coordinated synchronization point.

This determination is made at two separate times. One time is when a protected conversation is started. Protected conversations al...