Is there any way to have the JBoss connection pool reconnect to Oracle when connections go bad?

oracle jboss connection-pooling reconnect
Joshua picture Joshua · Sep 24, 2008 · Viewed 61.7k times · Source

We have our JBoss and Oracle on separate servers. The connections seem to be dropped and is causing issues with JBoss. How can I have the JBoss reconnect to Oracle if the connection is bad while we figure out why the connections are being dropped in the first place?

Answer

skaffman picture skaffman · Sep 28, 2008

Whilst you can use the old "select 1 from dual" trick, the downside with this is that it issues an extra query each and every time you borrow a connection from the pool. For high volumes, this is wasteful.

JBoss provides a special connection validator which should be used for Oracle:

<valid-connection-checker-class-name>
    org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker
</valid-connection-checker-class-name>

This makes use of the proprietary ping() method on the Oracle JDBC Connection class, and uses the driver's underlying networking code to determine if the connection is still alive.

However, it's still wasteful to run this each and every time a connection is borrowed, so you may want to use the facility where a background thread checks the connections in the pool, and silently discards the dead ones. This is much more efficient, but means that if the connections do go dead, any attempt to use them before the background thread runs its check will fail.

See the wiki docs for how to configure the background checking (look for background-validation-millis).

Related questions

SQLException: No suitable Driver Found for jdbc:oracle:thin:@//localhost:1521/orcl

I am trying to develop a Java EE application that connect to an Oracle database from eb service class but I encounter a SQLException: No suitable driver found for jdbc:oracle:thin:@//localhost:1521/orcl I have the ojdbc6.jar in …

Read More
Unable to define oracle datasource on Wildfly 10

I'm using wildfly-10.1.0.Final and I'm trying to add an oracle Datasource: <datasource jndi-name="java:jboss/datasources/OracleDS" pool-name="OracleDS" enabled="true"> <connection-url>jdbc:oracle:thin:@localhost:1523/pdborcl</connection-url> <driver>oracle</…

Read More
Why we have to declare dependencies on manifest of JBOSS 8 (wildfly)?

given the following EAR: my-app.ear my-ejb.jar my-webapp.war lib my-lib.jar my-ejb need the oracle library to work with oracle spatial in order to construct geometry and to store data. The module of oracle is correctly loaded by …

Read More