System::Session::start_transaction¶

Introduced : BIG-IP_v11.0.0

Start an iControl transaction, which combines the effects of a number of iControl methods into a single atomic transaction. Once an iControl client calls start_transaction, the handling of subsequent iControl requests changes until the client submits or rolls back the transaction, i.e. while the transaction is open. It is important to understand the characteristics of iControl requests made in this mode. iControl requests which modify the configuration are submitted for subsequent execution. The requests do not affect the configuration at the time they are made. iControl requests which query the configuration are executed immediately and do not see the effects of a pending transaction. iControl modify requests made outside a session with an open transaction affect the configuration immediately and do not see effects of any pending transactions. A transaction remains open until submit_transaction or rollback_transaction is called or until it is idle for too long. Reporting errors also differ while a transaction is open. Some classes of errors (such as invalid arguments) are returned by the method itself. The context for these errors should thus be as clear as without a transaction. However, most errors will be returned by the submit_transaction call. Note that this can make it difficult to determine which iControl method caused the error. If an error occurs at any time during a transaction, the transaction remains open, but is marked as errant. When submit_transaction is subsequently called, the transaction will actually be deleted, as if rollback_transaction has been called. Note that even if an error occurs, submit_transaction or rollback_transaction still must be called to properly close it. Not all interfaces and methods support transactions. These methods are processed per normal, i.e., executed immediately and not as part of the transaction. The documentation includes a note for those interfaces and methods which do not. The contents of pending transaction cannot be queried or modified. Only one transaction can be open at the same time in a single user session.