I’ve recently started using JBoss 6.1.0 and ran into an issue with setting min and max pool size in oracle-ds.xml. I tried two approaches (for both max and min pool size):

1. as a hardcoded number like <max-pool-size>5</max-pool-size>
2. as a configurable variable like <max-pool-size>${jdbc.maxPoolSize}</max-pool-size>

While the first approach worked fine the second one didn't. When the max and min pool sizes were set as configurable variables, the Java.sql.DataSource object created had max-pool-size=0 and min-pool-size=0. All the other settings (being set as configurable variables) in the same xml config file worked as expected. When I did further investigation I found that,

Org.jboss.resource.deployers.ManagedConnectionFactoryParserDeployer class reads all the oracle*-ds.xml files and sets the max/min pool size values to 0 even though I specified <max-pool-size>${jdbc.maxPoolSize}</max-pool-size>. It is not going and reading the value from the property file.

This had been working fine in JBoss 4.2