Siemens V 4.0 manual Time request, Transaction-monitored request/call, Transaction manager

Druck vom 24. 01.2001 17:01.06 fachwort

Glossary

T-ORB

The Transaction-monitored Object Request Broker allows local objects to send messages to remote objects with transaction monitoring. This means that not only the (persistent) states of the object, but also the messages undergo transaction monitoring. The sender does not have to worry about communication details.

time request

In the T-ORB procedure “time request”, a call is executed either at a certain time (absolutely) or with a certain time delay (relatively). A client does not wait for the result of a time request. Any events that may occur are thus discarded (see also →notifi- cation).

transaction

A transaction is an operation which is executed in accordance with the all-or-nothing rule. Transactions must comply with the ACID property (Atomicity, Consistency, Isolation, Durability):

A transaction is atomic, i.e. it is executed without “interruption” as a result of individual steps. A transaction changes an inconsistent state to a consistent state. Transactions are isolated, i.e. any inconsistent interim states that may exist are not visible from the outside. Their results are permanent, i.e. protected from errors.

see also →end of transaction

transaction-monitored request/call

A transaction-monitored request/call is carried out in a →transaction in accordance with the all-or-nothing rule.

Transaction-monitored calls can occur in a distributed way under T-ORB. They then form a →distributed transaction. A transaction-monitored call can be terminated with a commit or a rollback.

transaction manager

see →transaction monitor

transaction monitor

A transaction monitor or transaction manager coordinates a number of →resource managers and combines their →local transactions in a →distributed transaction operation to form a →global transaction.

transient

In contrast to a →persistent object, the life span of a transient object is limited by the life span of its process. Normal C++ objects are transient objects.

GINA V4.0 System Administrator Guide – September 2000 211