Ian McCallion wrote:
>
> [...]
> Yes, there needs to be coupling. It works roughly as follows:
>
> When a transaction running in a JVM completes, its transactional locks are
> converted into cache locks (owned by the cache). If another transaction in
> the same JVM needs the same data the cache lock is converted back to a
> transactional lock and given to the transaction. If a transaction running
> elsewhere needs the data it obtains the transactional lock. and when the
> transaction completes (and assuming the data was updated) a notification is
> sent to to any caches having a cache lock on the data and they flush the
> now-invalid data.
Good scheme... assuming that you are updating the data 100% through
the entity beans. But when was the last time you were able to force
all database users to go through a middleware layer? For one reason
or another, you'll find updates happening to the database that don't
go through EJB (legacy systems, batch jobs, and all the other places
where EJB isn't appropriate). And therein lies the rub. The database
isn't going to tell the EJB server to throw out its cached data, even
though it has changed.
-eric
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
