FYI, setQueryTimeout() will meter call Statement.setQueryTimeout() on
the underlying driver. JDBC drivers frequently either don't implement
this, or their implementation is very flawed. Unfortunately, we
haven't done detailed analyses of which drivers properly implement it
or not, so I don't know if DB2 has a proper implementation of it.
One way to test our whether it is supported is to write a small stand-
alone test case that directly creates a JDBC Connection and tries to
execute a slow or blocking SQL statement on a Statement after you
call setQueryTimeout() and see if it correctly times out. If it
doesn't, then the problem is with the driver. If it does, then
there's something wrong with OpenJPA and we can investigate further.
On Mar 22, 2007, at 4:47 PM, Don Brady wrote:
Hi,
I hope this is not off-topic on this list, but I cannot seem to
get QueryTimeout to work, using the persistence.xml below under
WebSphere 6.1 with a DB2 connection pool defined in WebSphere,
under OpenJPA 0.9.6.
It seems to just ignore the timeout specified and run to
completion no longer how long it takes.
I was wondering if the below should work or if there is another
way of setting a query timeout. I cannot find one.
Actually if I wrap it in a transaction, then I can set a timeout
on the transaction and that does work. But I was avoiding using a
transaction on the basis of advice in the book "Pro EJB" to omit
transactions if they are not needed, in the case of a read-only
query, because they may incur a performance penalty. Would that be
true in OpenJPA for a large read-only query or should I just use a
transaction and set the timeout on that?
Thank you for any comments!
Don
persistence.xml contents:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0"
xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://
java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
<persistence-unit name="mpu-prod" transaction-type="JTA">
<provider>
org.apache.openjpa.persistence.PersistenceProviderImpl
</provider>
<jta-data-source>jdbc/mship-prod</jta-data-source>
<non-jta-data-source>jdbc/mship-prod</non-jta-data-source>
<mapping-file>META-INF/orm-prod.xml</mapping-file>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="openjpa.jdbc.Schema" value="PROD" />
<property name="openjpa.DataCache" value="false" />
<property name="openjpa.RemoteCommitProvider" value="sjvm"
/>
<property name="openjpa.Log"
value="DefaultLevel=WARN, Runtime=INFO, Tool=INFO,
SQL=TRACE" />
<property name="openjpa.jdbc.DBDictionary"
value="db2(StoreCharsAsNumbers=false)" />
<property name="openjpa.TransactionMode" value="managed"
/>
<property name="openjpa.jdbc.TransactionIsolation"
value="read-committed" />
<property name="openjpa.ConnectionFactoryMode"
value="managed" />
<property name="openjpa.ConnectionFactoryProperties"
value="QueryTimeout=30"/>
</properties>
</persistence-unit>
</persistence>