WAS v8.5 > Administer applications and their environment > Welcome to administering Transactions > Administer the transaction service

Configure transaction properties for an application server

We can view or change settings for the transaction service. For example, we can change the location or default file size of the transaction log files, change transaction timeout properties, or change heuristic-related properties.

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 we want to move the transaction logs to a different storage device, or when we have to change the transaction service settings. Restart the application server to make configuration changes take effect.

1. In the dmgr console, click Servers > Server Types > WebSphere application servers > server_name. The properties of the application server, server_name, are displayed in the content pane.

2. Click [Container Settings] Container Services > Transaction Service. The Transaction Service settings page is displayed.
3. Ensure the Configuration tab is displayed.

4. Optional: To change the directory in which transaction logs are written, type the full path name of the directory in the Transaction log directory field. We can check the current runtime value of Transaction log directory by clicking the Runtime tab.

   If we do not enter a value for the Transaction log directory, the application server assumes a default location in the appropriate profile directory.

   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.

   We can also specify a size for the transaction logs, as described in the following step.

5. Optional: 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). Minimum transaction log file size that we can specify is 64K. If we specify a value that is less than 64K, or we 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;file_size
   dir://directory_name/directory_name;file_size
   /directory_name/directory_name;file_size

   For 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.

   c:\tranlogs;2M

   In a non-production environment, we can turn transaction logging off by entering ;0 in 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 Manage transaction logging for optimum server availability.

6. Optional: 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, verify 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 there is no timeout limit.

7. Optional: Review or change heuristic-related properties:

   Heuristic retry limit

   The number of times 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 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 resource" events 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 containing a one-phase resource. This setting configures last participant support (LPS) for the server. If we do not select this option, configure applications individually to accept the heuristic hazard.

8. 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.
9. 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.

10. Click OK, then save your changes to the master configuration.
11. Stop, then restart, the application server.

If you change the transaction log directory configuration property to an incorrect directory name, the application server restarts, but cannot open the transaction logs. Change the configuration property to a valid directory name, then restart the application server.

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, verify your non-root users and groups have matching identification numbers across machines.

Subtopics

• Transaction service settings
  Use this page to specify settings for the transaction service. 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.
• Transaction service custom properties
  WAS allows you to configure a number of custom properties for transaction services.

Related concepts:

Message processing in ASF mode and non-ASF mode

Related

Interoperate transactionally between application servers
Enable WAS to use an intermediary node for web services transactions
Configure Web Services Transaction support in a secure environment
Manage transaction logging for optimum server availability
Configure the runtime transaction service using scripting
Avoiding transaction timeouts in non-ASF mode

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