I found that someone else has encountered this problem
before. In this case it was a
stateless session
bean which created a CMP entity bean A which created 3 other CMP
entity beans in it's ejbStore method.
http://www.mail-archive.com/[email protected]/msg07146.html
My situation is similar I have a business method of a
session bean which is calling
the create methods
of two BMP entity beans is rapid fire fashion. The second entity
bean cannot be created until the first entity bean has
updated the database. My goal
is that the
session bean is a facade object which will guarantee that the
entities
are created or rollback them all. Is
this an unusual pattern for EJB when you have
what basically is a dependent object Entity bean?
Dave
-----Original Message-----
From:
Bolt, Dave [mailto:[EMAIL PROTECTED]]
Sent: Thursday, January 18, 2001 1:33 PM
To: jBoss
Subject: RE:
[jBoss-User] BMP and Container Managed Transactions was "Find er Methods
are sl ower when nothing is returned"
I tried making the changes. I even have tried the
following the session bean is ddc/DocumentLoader and the
entities are ddc/Product and
ddc/DocumentVersion. The session bean has valid ejb-ref entries for the
two entity
beans as well. As I understand it,
the declarations below should tell the container that all of the Home
and
Remote interfaces of all of the Beans
require a transaction.
BTW, I am not including any jboss.xml or jaws.xml files
in my EJB jar
Even with all of this, I have no success. The SQL code
in the ejbCreate method of DocumentVersion times out
on the INSERT statement because the Product record created by the
ejbCreate method of Product has not yet
been
committed.
I tried changing the isolation setting in Oracle, but
the driver only supports READ_COMMITTED and SERIALIZABLE,
the default setting being READ_COMMITTED
I agree the EJX tool in JBOSS 2.0 FINAL is buggy. I tend
to do most of the coding of the descriptor by hand.
<assembly-descriptor>
<container-transaction>
<description>Required</description>
<method>
<ejb-name>ddc/DocumentPart</ejb-name>
<method-name>*</method-name>
</method>
<method>
<ejb-name>ddc/Product</ejb-name>
<method-name>*</method-name>
</method>
<method>
<ejb-name>ddc/DocumentPartMedia</ejb-name>
<method-name>*</method-name>
</method>
<method>
<ejb-name>ddc/DocumentLoader</ejb-name>
<method-name>*</method-name>
</method>
<method>
<ejb-name>ddc/DocumentVersion</ejb-name>
<method-name>*</method-name>
</method>
<trans-attribute>Required</trans-attribute>
</container-transaction>
</assembly-descriptor>
-----Original Message-----
From:
Nortje, Andrew [mailto:[EMAIL PROTECTED]]
Sent: Thursday, January 18, 2001 12:13 PM
To: 'jBoss'
Subject: RE:
[jBoss-User] BMP and Container Managed Transactions was "Find er Methods
are sl ower when nothing is returned"
Dave
I think the problem may be in the way you have
configured the transactions in jBoss.
Use the ejx GUI for configuring transactions. I use an
older ejx, the one that comes with jBoss 2.0 FINAL I think is broken or
partially broken.
Make the method on your session bean Required. That way
it will start a transaction if one does not exist and all subsequent
operations will be under that transaction. Make sure other methods, that
need to be part of the same transaction, are also marked Required. I
don't believe jBoss is behaving badly, as I say I have this sort of
thing working. Check your config carefully.
An example of some ejb-jar.xml config for
transactions
<assembly-descriptor>
<container-transaction>
<description>Required</description>
<method>
<ejb-name>Customer</ejb-name>
<method-intf>Home</method-intf>
<method-name>buy</method-name>
<method-params>
<method-param>com.uni.trader.ShoppingCart</method-param>
<method-param>com.uni.account.PaymentDetails</method-param>
</method-params>
</method>
<trans-attribute>Required</trans-attribute>
</container-transaction>
</assembly-descriptor>
-----Original Message-----
From:
Bolt, Dave [mailto:[EMAIL PROTECTED]]
Sent: Thursday, January 18, 2001 11:10 AM
To: jBoss
Subject: RE:
[jBoss-User] BMP and Container Managed Transactions was "Find er Methods
are sl ower when nothing is returned"
I tried changing the beans to reentrant = true. I did
have them marked as non-reentrant. Unfortunately it did not fix the
problem. My create methods are setting all of the attribute
data.
Here's the basic issue. It looks like the connection
pool is giving me different connections for each of my beans. As a
result the SQL in the beans is isolated transactionally from the other
beans. I guess the basic question is this. If I have BMP entity beans,
running under container-managed transactions. And if I have beans that
have dependency relationships (For example a foreign-key relationship in
the DB) in the back-end database. How do I write my SQL and connection
pool code so that the beans work properly in the EJB transaction
context. Is my only option to choose a isolation level that allows dirty
reads?
How do I set the isolation level in my jboss
configuration? (Since the JBOSS web site is down, I can't look at the
docs)
Do I have to do it manually via the Connection
setTransactionIsolation method any time I lookup a connection?
What if I have a mix of BMP, CMP, and (horror)
SQL in a SessionBean?
Thanks
Dave
-----Original Message-----
From: Nortje,
Andrew [mailto:[EMAIL PROTECTED]]
Sent: Thursday, January 18, 2001 10:20 AM
To: 'jBoss'
Subject: RE:
[jBoss-User] BMP and Container Managed Transactions was "Find er Methods
are sl ower when nothing is returned"
Dave
I am doing something similar to what you are and it
works after much struggling i.e. I create and use beans under a single
transaction context. If something fails created rows are rolled back
etc.
Anyway I recognize the timeout error, I also had this
error. It turned out I was making reentrant calls to my entity beans and
they were not marked reentrant. You may have a similar problem. Try make
your entity beans reentrant (ejb-jar.xml) then test your code. If it
then works then you are making reentrant calls, you can then take it
from there.
Also make sure your create() method correctly populates
all the bean data (attributes), i.e. after create() the bean instance is
taken out the pool and is assigned.
-----Original Message-----
From:
Bolt, Dave [mailto:[EMAIL PROTECTED]]
Sent: Thursday, January 18, 2001 9:21 AM
To: jBoss
Subject: [jBoss-User]
BMP and Container Managed Transactions was "Finder Methods are sl ower
when nothing is returned"
It turns out that it is a database thing, but then again
it isn't. Here's a better description.
I have three EJBs, a session bean and two entity beans.
The entity beans have a one-to-many relationship. If I had EJB 2.0 I
would use the container managed relationship features to handle all of
this. Right now, it's being done the hard way with BMP code. Anyway, the
session bean has a business method marked with a RequiresNew transaction
attribute and it calls the create method of first the master bean and
then the entity bean. In the database (Oracle 8i) the detail records can
only exist if the master record exists (foreign key
constraint).
Each of the entity beans obtains a connection from the
connection pool with the following code.
private Connection
getConnection()
{
Context ctx
= null;
Connection con =
null;
DataSource ds = null;
try
{
ctx = new InitialContext();
ds = (DataSource)ctx.lookup(JNDINames.DB_POOL);
con = ds.getConnection();
return con;
}
catch(NamingException
ne)
{
System.out.println(ne.getMessage());
System.out.println(ne.getExplanation());
ne.printStackTrace();
throw new EJBException(ne);
}
catch(SQLException
se)
{
System.out.println(se.getMessage());
se.printStackTrace();
throw new EJBException(se);
}
}
The problem that I am having is that the create method
of the master bean is adding records to the database, but the changes
are not visible to the detail bean via it's connection. It could be an
isolation level thing (I haven't found in JBOSS were you set the
isolation level for an Oracle connection pool).
What I want to have happen is that the Session bean will
start a transaction (RequiresNew) which will include the create methods
of the Master and Detail beans (Requires), but it looks like since I am
getting different connections from the connection pool that the ability
of the container to manage the transactions is being
compromised. The error that I finally get in my code is
ORA-02049: timeout: distributed transaction waiting for lock.
Any ideas?
Dave
-----Original Message-----
From:
Cook, Thomas [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, January 17, 2001 6:24 PM
To: 'jBoss'
Subject: RE:
[jBoss-User] Finder Methods are slower when nothing is return ed
Possible a database thing? If nothing is returned,
maybe it is doing a sequential search?
Tom
--
Tom Cook
Systems Development
Australian Submarine Corporation
Mersey
Road
Outer Harbour
+61 8
8348 7645
"From the instant I picked your book
up, until the moment I put it down, I was convulsed with laughter.
I fully intend to read it one day."
- Groucho
Marx
-----Original Message-----
From: Bolt, Dave [SMTP:[EMAIL PROTECTED]]
Sent: Thursday, January 18, 2001
5:01 AM
To:
[EMAIL PROTECTED]
Subject: [jBoss-User]
Finder Methods are slower when nothing is returned
I'm trying to write some code to use BMP Entity beans to update
an Oracle 8i database.
I have a session bean
that is doing the data loading from an XML file. I want to use the
Entity
bean to see if the data exists (via a
Finder method) and then either create or update the
record depending on the status.
I am
seeing that performance is very fast if the record already exists,
whereas it is very slow if no
records can be
found. Has anyone else noticed a difference in performance in the
Finder's thanks
Dave Bolt
There is always bandwidth, just none for you.
