TMF Introduction (G06.24+)

Transaction Coordination

HP NonStop Transaction Management Facility (TMF) Introduction—522414-001

2-2

Coordinating Distributed Transactions

Distributed transactions are transactions that access data located at multiple nodes of

a network, or that access data by means of requesters or servers at multiple nodes of

a network. There are two kinds of distributed transactions:

•

Homogeneous transactions are distributed transactions that are processed by the

same type of transaction manager operating on the same platform. For example,

part of the transaction may be processed by TMF at NonStop Server (Node) A and

another part may be processed by TMF at NonStop Server (Node) B.

•

Heterogeneous transactions are distributed transactions that are processed by

different types of transaction managers operating on multiple platforms. For

example, one part of the transaction may be processed by TMF on a NonStop

server, and another part by the Microsoft Distributed Transaction Coordinator

(Microsoft DTC) running on another platform. In heterogeneous transaction

processing, TMF can start a transaction and then subcontract parts of it to one or

more foreign transaction managers. Alternatively, a foreign transaction manager

can begin a transaction and then subcontract parts of it to TMF.

TMF is an open transaction manager; its commit protocol is open and public, and it

supports coordination with resource managers and remote transaction managers

through the use of transaction gateways. These elements work together to make

possible any kind of distributed transaction processing, whether homogeneous or

heterogeneous. They enable HP customers to integrate data located on many

different types of databases and platforms to conduct their business operations.

Figure 2-1. Local Transaction

$DATA1

$AUDIT

$DATA2

\DALLAS

TMF

User

Application

VST043.vsd