Configuring transaction properties for an application server
You can view or change settings for the transaction service. For example, you can change the location or default file size of the transaction log files, change transaction timeout properties, or change heuristic-related properties.
About this task
The transaction service is a server runtime component that can coordinate updates to multiple resource managers to ensure atomic updates of data. Transactions are started and ended by applications or the container in which the applications are deployed.
You might undertake this task when you want to move the transaction logs to a different storage device, or when you have to change the transaction service settings. You must restart the application server to make configuration changes take effect.
In the administrative console, click
.The properties of the application server, server_name, are displayed in the content pane.
.The Transaction Service settings page is displayed.
- Ensure that the Configuration tab is displayed.
To change the directory in which transaction logs are written, type the full path name of the
directory in the Transaction log directory field.
You can check the current runtime value of Transaction log directory by clicking the Runtime tab.
If you do not enter a value for the Transaction log directory, the application server assumes a default location in the appropriate profile directory.Note: If you change the transaction log directory, apply the change and restart the application server as soon as possible, to minimize the risk of problems occurring before the application server is restarted. For example, if there is a problem and the server fails with in-flight transactions, when the server restarts, it uses the new log directory and cannot automatically resolve in-flight transactions that were recorded in the old log directory.
You can specify a size for the transaction logs, as described in step 5.
To change the size of transaction log files, modify the Transaction log
directory field to include a file size setting. Use one of the following formats, where
directory_name is the name of the transaction log directory and
file_size is the disk space allocation for the transaction log files, specified
in kilobytes (nK) or megabytes (nM). The minimum transaction
log file size that you can specify is 64K. If you specify a value that is less than 64K, or you do
not specify a value for the file size, the default value of 1M is used.
;file_size <!-- This format keeps the default directory -->
/directory_name/directory_name;file_sizeFor example, for a Windows system, the following entry specifies that transaction log files are created in the directory c:\tranlogs with a size of 2 megabytes.
In a non-production environment, you can turn transaction logging off by entering
;0in the Transaction log directory field (do not enter a directory name). Do not turn transaction logging off in a production environment because this prevents recovery after a system failure, and therefore data integrity cannot be guaranteed.
For more information about transaction log sizes, see Managing transaction logging for optimum server availability.
Review or change the value of transaction timeout properties:
- Total transaction lifetime timeout
- The number of seconds to allow for a transaction that is started on this server, before the transaction service initiates timeout completion. If a transaction does not begin completion processing before this timeout occurs, it is rolled back. A value of 0 (zero) indicates that this timeout does not apply, and therefore the maximum transaction timeout is used instead. Application components can override the total transaction lifetime timeout for their transactions by setting their own timeout value.
- If you are running your messaging system in non-ASF mode, you must make sure that this property is correctly configured with the NON.ASF.RECEIVE.TIMEOUT message listener service custom property so that unwanted transaction timeouts are avoided. See the related links for more details.
- Maximum transaction timeout
- The number of seconds a transaction that is propagated into this application server can remain
inactive before it is ended by the transaction service. This value also applies to transactions that
are started in this server, if their associated applications do not set a transaction timeout and
the total transaction lifetime timeout is set to 0 (zero).
This value must be equal to, or greater than, the total transaction lifetime timeout. A value of 0 (zero) indicates that this timeout does not apply. In this situation, transactions that are affected by this timeout never time out.
- Client inactivity timeout
- The number of seconds after which a client is considered inactive and the transaction service ends any transactions associated with that client. A value of 0 (zero) indicates that there is no timeout limit.
Review or change heuristic-related properties:
- Heuristic retry limit
- The number of times that the application server retries a completion signal, such as commit or rollback. Retries occur after a transient exception from a resource manager or remote partner, or if the configured asynchronous response timeout expires before all Web Services Atomic Transaction (WS-AT) partners have responded.
- Heuristic retry wait
- The number of seconds that the application server waits before retrying a completion signal, such as commit or rollback, after a transient exception from a resource manager or remote partner.
- Enable logging for heuristic reporting
- Select this option to enable the application server to log
about to commit one-phase resourceevents from transactions that involve a one-phase commit resource and two-phase commit resources.
- Heuristic completion direction
- Select the direction used to complete a transaction that has a heuristic outcome; either the
application server commits or rolls back the transaction, or depends on manual completion by the
administrator.The heuristic completion direction property specifies how a transaction is completed in the following situations:
- The transaction manager reports a heuristic outcome for a last participant support (LPS) resource.
- The heuristic retry limit is exceeded during the recovery of a subordinate server in a distributed transaction.
- The transaction is imported from a Java™ EE Connector Architecture (JCA) provider.
This property applies only to transactions that are in the situations just described.
- Accept heuristic hazard
- Select this option to specify that all applications on this server accept the possibility of a heuristic hazard occurring in a two-phase transaction that contains a one-phase resource. This setting configures last participant support (LPS) for the server. If you do not select this option, you must configure applications individually to accept the heuristic hazard.
- Optional: To change the default WS-Transaction specification level to use for outbound requests that include a web Services Atomic Transaction (WS-AT) or Web Services Business Activity (WS-BA) coordination context, select the specification level from the Default WS-Transaction specification level list.
Review or change other configuration properties, to suit your requirements.
For more information about the properties of the transaction service, see the topic about Transaction service settings.
- Click OK, then save your changes to the master configuration.
- Stop, then restart, the application server.
What to do next
If you are running the application server as non-root, modify the permissions on the new transaction log location. To use peer recovery of transactions on a shared device with non-root users, make sure that your non-root users and groups have matching identification numbers across machines.