Filter
Top Products
Transaction Management
4.1 Overview
this transaction is removed from memory and can no longer be monitored by the
command.
The RTR
DUMP JOURNAL
command can be used to trace and review the flow of a
transaction. The RTR journal saves all of the information about a transaction,
its transaction journal state, the transaction messages (records) received from the
RTR client, and the content of a message sent to the server. The information will
be kept until a transaction is committed and forgotten.
The RTR
SET TRANSACTION
command is used to modify a live transaction to
change the current state of a transaction to a new state. This command can be
used to circumvent a difficult situation. For example, in a situation where two
shadowed servers are configured, the system administrator might decide not
to replay (recover) all transactions in a shadowed RTR journal after a failure.
The
SET TRANSACTION
command could set specified transactions in a PRI_DONE
or remember state to a DONE state and avoid the delay of transactions being
remembered from a journal for fast recovery. The
SET TRANSACTION
command
should only be used by experienced RTR system administrators as the command
introduces the risk of corrupting or losing transactions if used incorrectly. It can
be used on the backend only and the RTR log file must be turned on for this
command.
Log file entries are made for all transaction state changes for debugging and
auditing purposes.
4.1.0.1 Command Line Examples
An example of the use of the
SET TRANSACTION
command:
RTR> start rtr
RTR> set log/file=settran
RTR> set transaction/state=PRI_DONE/new_state=DONE/facility=Facility1/partition=Partition1 *
This example would set all transactions with the wildcard * in the current state
of PRI_DONE (remember) to DONE on the facility Facility1 and the partition
Partition1. The log file, settran, would record the transaction state changes.
The changes could be viewed with the
SHOW TRANSACTION
command or the
DUMP
JOURNAL
command. In a shadow recovery situation this would clear the journal of
remember transactions and provide for a fast recovery of access to the database if
needed.
For detailed information on these commands see Chapter 6.
4.1.1 Exception Transactions
Transactions can cause servers to fail after the VOTE phase and impact
availability of a server in a recovery. These "EXCEPTION" transactions can
now be flagged by RTR as "fail transactions" after the user sets the attempts
at recovery from a failure with the
SET PARTITION/RECOVERY_RETRY_COUNT=nn
command. They then can be identified and removed from the RTR journal
and from the system to allow recovery to continue with the
SET TRANSACTION
command. In the case of a flagged "EXCEPTION" transaction the system
administrator can take action by changing the state of the "EXCEPTION"
transaction to that of "DONE" with the
SET TRANSACTION/STATE=EXCEPTION
/NEW_STATE=DONE
to allow the recovery to continue.
4–2 Transaction Management