Re: Connection.isValid(int timeout) implementation - Mailing list pgsql-jdbc

From Vlad Arkhipov
Subject Re: Connection.isValid(int timeout) implementation
Date
Msg-id 4FD304AF.30707@dc.baikal.ru
Whole thread Raw
In response to Re: Connection.isValid(int timeout) implementation  (Craig Ringer <ringerc@ringerc.id.au>)
List pgsql-jdbc
On 06/09/2012 03:19 PM, Craig Ringer wrote:
On 06/09/2012 10:28 AM, Vlad Arkhipov wrote:
However there are some projects that strongly rely on this method to test the connection (for example Arjuna Transaction Manager that is used by JBoss Application Server). Are there any plans of implementing this feature?
Really? JBoss AS 7.1.1.Final is quite happy with PgJDBC (postgresql-9.1-901-1.jdbc4.jar) here. What's your configuration? Your -ds.xml or jboss-cli "create datasource" command?
They have a memory leak in JTS 4.16.4 (JBoss AS 7.1.1), so if you use XA datasource and the driver does not implement Connection.isValid, Transaction Manager will create and store in memory a new XA connection every 2 minutes.

Good to know. Please post the reference to the JBoss JIRA ticket - assuming, as it sounds like, you're referring to an acknowledged bug.

It sounds like it'll be important to make sure that isValid() makes it into the 9.2 JDBC driver release.
https://issues.jboss.org/browse/JBTM-1183
Re your -ds.xml, does setting an explicit connection validator help?

<validation>     
<valid-connection-checker class-name="org.jboss.jca.adapters.jdbc.extensions.postgres.PostgreSQLValidConnectionChecker"></valid-connection-checker>
<exception-sorter class-name="org.jboss.jca.adapters.jdbc.extensions.postgres.PostgreSQLExceptionSorter"></exception-sorter>
</validation>


Otherwise I think it'll use org.jboss.jca.adapters.jdbc.extensions.novendor.JDBC4ValidConnectionChecker, which I expect won't work without isValid().
Yes, I have these lines in the datasource description. However the recovery subsystem does not use them.
I debugged a bit more and found out that it's also necessary to specify the recovery plugin.

<recovery no-recovery="false">
  <recovery-plugin class-name="org.jboss.jca.core.recovery.ValidatingManagedConnectionFactoryRecoveryPlugin" />
</recovery>

pgsql-jdbc by date:

Previous
From: Craig Ringer
Date:
Subject: Re: Connection.isValid(int timeout) implementation
Next
From: Craig Ringer
Date:
Subject: Re: get/setReadOnly broken if default_transaction_read_only on