sync-on-commit-only ?

[bergler]

In my application I call several business methods on a BMP entity
within one transaction and I observed that after each business method
ejbStore is invoked, although in my eyes this is not necessary. It
would be enough to call it once immediately before the commit. The
only problem I could possibly get is that queries (e.g. finder
methods) from within the same transaction would see the database in
the state it was before the transaction.

In my application change of this behaviour this would reduce database
traffic to a fraction, because I do several business method call
on the same EJB within the same transaction.

Can I use the undocumented (I use the documentation as of September
30, 2002 8:04) feature <sync-on-commit-only>true<sync-on-commit-only>
field in the container-configuration for this? Why is this feature in
the container configuration but not overridable from jboss.xml??

Greetings
Roland

[adrian.brock]

You can add a method

boolean isModified();

Which the container will invoke to find
out whether a store is necessary.
This is a jboss specific feature.

Pretty much anything that can comes from standardjboss.xml
can be overridden in jboss.xml
They use the same parser code.

Regards,
Adrian

[bergler]

Thats not the same for me: The state at the beginning of a transaction is very similar to the state at the end, so there would be very little to store, but intermediate states can be completely different. So when ejbStore is invoked after every business method very much state changes will be stored unneccessarily.

The sync-on-commit flag is missing from the jboss_3_0.dtd, so are you sure it can be overridden?

[adrian.brock]

Yes,

public void importJbossXml(Element element) throws DeploymentException
{
// everything is optional to allow jboss.xml to modify part of a configuration
// defined in standardjboss.xml
// set call logging
callLogging = Boolean.valueOf(getElementContent(getOptionalChild(element, "call-logging"), String.valueOf(callLogging))).booleanValue();
// set synchronize on commit only
syncOnCommitOnly = Boolean.valueOf(getElementContent(getOptionalChild(element, "sync-on-commit-only"), String.valueOf(syncOnCommitOnly))).booleanValue();

Raise a bug report for the dtd.

Regards,
Adrian

[bergler]

I dont understand what the code does, but it does NOT work when overridden from jboss.xml.

I made some tests setting <sync-on-commit-only> from standardjboss.xml and jboss.xml and I can see an effect only if I set the flag in standardjboss.xml.

I am quite shure that the configuration settings (other than sync-on-commit-onl>) in jboss.xml are correct.