Figure 6-3 Client Applications Change Both Iis Process State And Application Data - Sun Microsystems iPlanet Integration Server 3.0 Process System Manual

Monitoring and Managing Two-Phase Commit
Figure 6-3
Engine Operations
For example, a process client application typically interacts with the engine to start
an activity, performs the activity by updating application data, and then interacts
with the engine again to complete the activity. If, for some reason, the update of
application data fails, the CompleteActivity operation should not succeed. Or,
similarly, if for some reason the CompleteActivity operation fails, the update of
application data should not succeed.
The iIS two-phase commit protocol facilitates the synchronization of iIS engine
operations with application transactions by letting you place iIS operations in a
transactional context. As with application database transactions, the iIS two-phase
commit protocol lets you split processing of iIS transactions into two phases: the
first phase—preparing—guarantees that the operation (transaction) can either
commit or roll back; the second phase actually performs the commit (or rollback).
NOTE
200 iPlanet Integration Server • Process System Guide • August 2001
Client Applications Change Both iIS Process State and Application Data
iIS Process
iIS Process
Engine
"Rollback" in this usage is equivalent to "undo." For example,
rolling back a CompleteActivity operation cancels the request to
complete the activity.
Client Applications
Application
Services
Application
Transactions
Enterprise
Databases