Sun Java System Application Server Enterprise Edition 8.1 2005Q2 Performance Tuning Guide

Transaction Service Settings

The transaction manager makes it possible to commit and roll back distributed transactions.

A distributed transactional system writes transactional activity into transaction logs so that they can be recovered later. But writing transactional logs has some performance penalty.

Monitoring the Transaction Service

Transaction Manager monitoring is disabled by default. Enable monitoring of the transaction service with the Admin Console at Configurations > config-name > Monitoring.

You can also enable monitoring with these commands:

set serverInstance.transaction-service.monitoringEnabled=true
reconfig serverInstance

Viewing Monitoring Information

When you have enabled monitoring of the transaction service, view results

The following statistics are gathered on the transaction service:

Here is a sample of the output using asadmin:

********** Stats for JTS ************
 total-tx-completed = 244283
 total-tx-rolled-back = 2640
 total-tx-inflight = 702
 isFrozen = False
 inflight-tx =
 Transaction Id , Status, ElapsedTime(msec)
 000000000003C95A_00, Active, 999

Tuning the Transaction Service

This property can be used to disable the transaction logging, where the performance is of utmost importance more than the recovery. This property, by default, won’t exist in the server configuration.

Disable Distributed Transaction Logging

To disable distributed transaction logging with the Admin Console, go to Configurations > config-name > Transaction Service. Click on Add Property, and specify:

Recover On Restart (Automatic Recovery)

To set the Recover on Restart attribute with the Admin Console, go to Configurations > config-name > Transaction Service. Click the Recover check box to set it to true (checked, the default) or false (un-checked).

You can also set automatic recovery with asadmin, for example:

asadmin set server1.transaction-service.automatic-recovery=false

When Recover on Restart is true, the server will always perform transaction logging, regardless of the Disable Distributed Transaction Logging attribute.

If Recover on Restart is false, then:

Keypoint Interval

The keypoint interval determines how often entries for completed transactions are removed from the log file. Keypointing prevents a process log from growing indefinitely.

Frequent keypointing is detrimental to performance. The default value of the Keypoint Interval is 2048, which is sufficient in most cases.