BizTalk™ Unleashed

State Management

An XLANG Scheduler Engine maintains the execution and messaging state of a schedule instance. This state must be correctly restored across system failures, in the presence of transactions, or when schedules are rehydrated. When a system recovers from a failure, the state of all the running schedules must be restored to some known point. If a transaction fails, the schedule must discard the changes caused by the failed transaction and restore the state prior to that transaction before continuing. When a schedule instance is dehydrated, the bulk of its state is saved to a database, with only some vestigial elements needed to detect any events that might trigger rehydration. Hence, state management is an important function of the ...