Hi,

I enabled JCS caching for a couple of classes in the hibernate. When I start the server, I'm getting log statements saying Hibernate's caching class and also the logging statements by JCS, correctly showing the name of the classes for I've enabled the caching.

However, when I make a call to load the object using session.load(), hibernate is printing the SQL query that is used for fetching the object from the database.

Also, when I run hibernate in debug mode, the log statements shows as follows:



After this the log statements show that hibernate is making call to the database and fetching the entity.

From the log statements it looks like cache is hit for the corresponding entity but still hibernate makes a call to database for fetching the entity. Can you please explain me what I need to configure so that Hibernate uses the JCS cache?

Regards,
Balakrishnan.

P.S: My current configuration file contains the following single line for JCS caching(with separate cache.ccf file for JCS configuration).
<jcs-cache class="com.maco.common.Member" usage="nonstrict-read-write" />

Looks like it is not hitting an actual cached entity. Looks like it is just finding a timestamp ("soft lock") there.

You would see another message from NonstrictReadWriteCache if it fould the actual object.

Perhaps you are not completing the session/transaction correctly, so the "soft lock" is not being released.

Can you please explain it a bit. Here's the scenario in which I'm got the above debug statements.

(1) Freshly start all the servers.

(2) User logs into the system. In this case a BMT session bean is used for fetching the user details from the database. Note that no transaction is used in this case. Just I'm using session.load() for fetching the user details from the user details. Also, no details are written to the database using any other beans. When the method is finished, session is properly closed.

(3) Next operation is Update user profile. In this case also, as per our logic first operation is fetching the user details from the database. I'm using the same method and fetching the user details. Since JCS caching is enabled I thought user details will be fetched from cache. But it is not happening :-(

Can you tell me due to any othe reasons(other than not properly closing the transaction/session), the "soft-lock" may happen?

Here we go again:


"note that no transaction is used"


Why does everyone seem to think that you don't need transactions for read-only operations!?

You should do *everything* in a transaction. It is faster and safer.

Ok. I modified that code so that the getter methods also work inside transaction. But still the object is not fetched from the cache. :-(. I've properly checked for transaction and session closure.

Is there any mechanism available by which I can see the "soft-lock"s that are made to the cached object? (Just for debugging)

On side note, you said performing operations inside transactions make operations faster and safer. "Safer" ok. How does a transaction make fetch operations faster? Just curious :-)

I hope you read the bit in the Hibernate documentation that says you have to use the hibernate Transaction API when using the process-level cache. (This is a requirement that is relaxed in Hibernate 2.1 CVS.)




When you run a JDBC connection in autocommit mode it doesn't mean "no transaction" it means "a new transaction for every single database access".

Oops! I'm missed the point. Really sorry for wasting your time :-(. I was using the bean's transaction. Since you said this restriction will be removed in 2.1 release, I'll use this caching once 2.1 released.

Again sorry for not reading the doc.

Oops! I'm missed the point. Really sorry for wasting your time :-(. I was using the bean's transaction. Since you said this restriction will be removed in 2.1 release, I'll use this caching once 2.1 released.

Again sorry for not reading the doc.

Dude, all you need to do is add the calls to:


Transaction tx = session.beginTransaction();
...
...
tx.commit();



Into your code.


As long as you are set up to use JTATransaction, and have a TransactionManagerLookup configured, Hibernate will intergrate cleanly with the Bean's JTA transaction.


Just try it out!