Chapter 12. Transactions Subsystem Tuning

If your environment uses XA distributed transactions, you can tune the transaction manager’s log store for better performance.

The default transaction log store uses a simple file store. For XA transactions this type of log store can be inefficient, as it creates one system file for each transaction log. Especially for XA transactions, a journal store is much more efficient as it uses a journal that consists of one file for all transactions.

For better XA transaction performance, it is recommended that you use a journal log store. For Red Hat Enterprise Linux systems, you can additionally enable asynchronous I/O (AIO) on the journal store to further improve performance.


For Red Hat Enterprise Linux systems, if you are enabling asynchronous I/O (AIO) on the journal store, ensure that the libaio package is installed.

Enable the Journal Log Store Using the Management Console

  1. Navigate to ConfigurationSubsystemsTransactions → and click View.
  2. Select the Store tab, and click Edit.
  3. Select the Use journal store check box.
  4. Optional: For Red Hat Enterprise Linux systems, select the Journal store enable async io check box.
  5. Click Save.

Enable the Journal Log Store Using the Management CLI

  1. To enable the journal log store using the management CLI, use the following command:

  2. Optional: For Red Hat Enterprise Linux systems, use the following command to enable journal log store asynchronous I/O:

    /subsystem=transactions:write-attribute(name=journal-store-enable-async-io, value=true)