Caching CMP entity beans in a Weblogic cluster

We are currently looking for pilot customers for our clustered transactional
          CMP Entity EJB cache. It works with the Weblogic's transaction management
          and CMP implementation to coherently and transactionally cache CMP Entity
          EJBs in a cluster, providing close to zero-latency access to CMP data --
          even for read/write beans.
          Problem Description:
          Performance of J2EE applications using CMP Entity EJBs degrades when running
          in a cluster due to the disabling of Entity EJB caching (i.e. the
          requirement to set db-is-shared=true).
          Requirements:
          1. You are running Weblogic in a cluster
          2. Your application has at least one Weblogic CMP Entity EJB
          3. The data related to your Weblogic CMP Entity EJB is only being updated by
          Weblogic CMP Entity EJBs (i.e. you could set db-is-shared=false if you were
          not clustering)
          Solution Description:
          1. No source code or deployment descriptor changes
          2. One additional automated build step (ANT-compatible)
          3. Configurable cache (e.g. size-limited)
          We plan to begin introduce the product to pilot customers on 28 January
          2002, so if you are interested, please drop me an email at
          [email protected]
          Peace,
          Cameron Purdy
          Tangosol, Inc.
          Clustering Weblogic? You're either using Coherence, or you should be!
          Download a Tangosol Coherence eval today at http://www.tangosol.com/

Could somebody please guide me on this?
Dipak Jha

Similar Messages

Caching CMP Entity Beans with 9.0.2

Hi,
my CMP Entity Bean is accessed from a JSP-Page through a Stateless Session Bean. The Session-Bean executes findAll() on the Entity-Bean and the JSP-Page iterates over the Collection and displays the Fields through their getter-Methods. It turns out that every getXXX Methods results in a complete load of the Bean from the Database, so for 3 database-records with 4 attributes i get 12 SELECT - statements and 12 Activate/Load/Passivate cycles of the Entity Bean!!!!
I tried to setup the attributes in orion-ejb-jar.xml correctly, but that didn't show a difference:
-) exclusive-write-access="true" does only work in "read-only" mode (see oc4j_ejb_guide_r2.pdf)
-) setting timeouts didnt work
My Entity Bean settings are:
exclusive-write-access="true"
instance-cache-timeout="60"
max-instances="100"
max-tx-retries="0"
pool-cache-timeout="100"
The EJB-Callbacks are:
first the Session-Bean is created, and findAll() is executed - then all Entity-Beans are passivated again:
TestManBean Constructor called 1
TestManBean.setSessionContext() 1
TestManBean.ejbCreate() 1
PersonBean Constructor called 1
PersonBean.setEntityContext() 1
PersonBean.ejbActivate() 1
PersonBean.ejbLoad() 1
PersonBean Constructor called 2
PersonBean.setEntityContext() 2
PersonBean.ejbActivate() 2
PersonBean.ejbLoad() 2
PersonBean Constructor called 3
PersonBean.setEntityContext() 3
PersonBean.ejbActivate() 3
PersonBean.ejbLoad() 3
PersonBean.ejbPassivate() 1
PersonBean.ejbPassivate() 2
PersonBean.ejbPassivate() 3
now for every getXXX-Methods the following occurs:
PersonBean.ejbActivate() 3
PersonBean.ejbLoad() 3
PersonBean.ejbPassivate() 3
I user OC4J 9.0.2 Production with Oracle 8.1.6.
How can I turn on Entity-Bean Caching?
Thanks,
Gilbert

Hi Gilbert,
Someone recently asked a similar question to yours. Perhaps that thread will
be helpful to you?
Author: Valeri Kireitchik
Subject: how to set exclusive-write-access="true"
Date: May 17, 2002 10:18 PT
URL:
Re: Get the Table name by providing the Sequence name
The same person (Valeri) also asked his question on two other forums:
http://www.elephantwalker.com/rfa?id=549
http://www.mail-archive.com/orion-interest%40orionserver.com/msg19037.html
Good Luck,
Avi.

Deploying CMP Entity Beans in Weblogic

How to generate/convert the Orion xml file to Weblogic_RDBMS ?
Thx

petstore 1.3 will be available for the upcoming beta of weblogic 7.0...
Andrew Sliwkowski(BEA)
[email protected]
"Nitin Sawant" <[email protected]> wrote in message
news:3c04f6cd$[email protected]..
>
Appreciate if you can share your plans on releasing a petstore 1.3 patchfor weblogic.
>
>
i am having problems deploying CMP Entity Beans in petstore 1.3 where theprimary
key class is defined as java.lang.Object in the ejb-jar.xml descriptor(<prim-key-class>java.lang.Object</prim-key-class>).
Does weblogic 6.1 with 1.3 features enabled support the above feature.
Thanks,

Using oracle db sequence for auto generating of PKs for CMP entity beans

Hi,
I have read quite a number of threads about (auto) generation of keys for primary keys for the CMP entity beans.
My requirement is I am migrating an application deployed on Weblogic to oc4j. The application is using cmp entity beans with auto key generation using a sequence in the Oracle db. This is specified in weblogic-cmp-rdbms-jar.xml file like below:
<automatic-key-generation>
<generator-type>Oracle</generator-type>
<generator-name>REPUSER.DEPT_REPORT_SEQ</generator-name>
<key-cache-size>1</key-cache-size>
</automatic-key-generation>
In the ejb-jar.xml, it is specified as:
<prim-key-class>java.lang.Integer</prim-key-class>
<primkey-field>id</primkey-field>
Now, I need to migrate this to oc4j. Can somebody suggest me options and clarify my questions kindly?
1) I have read articles that say that in the ejb-jar.xml, we need to specify <prim-key-class>java.lang.Object</prim-key-class> and this will create a column called 'autoid' in the respective entity table in the Oracle db.
- How can I use this to assign the value to my primary field, say, id?
2) Now, with the latest oc4j, can I use Oracle database sequence as the key generator for the values of the PKs just by specifying in the xml descriptor ejb-jar.xml?
2.a) If yes, is there any article that explains with the code?
2.b) If no, what are the alternatives I have?
I have read many discussions that say that we can create a stateless session bean that can lookup the database sequence using simple JDBC call to return the nextval of the sequence. The SSB should be called in the ejbCreate() of the entity bean.
My related question is, what is recommended for oc4j? What are limitations of the various options for the latest oc4j available?
How should I go about deploying this kind of ejbs in oc4j?
Any help and pointers are welcome. Please help.
Thanks a lot.
Vadi

Hello ,
Instead of exposing a get/set method for each arribute of your bean (corresponding to database table) expose only one object.
For example
public class CustomerBean implements javax.ejb.EntityBean{
private CustomerVO objCustomer;
private String customerName;
private String customerMail;
private String customerType;
public CustomerVO getCustomer(){
return this.objCustomer;
public void setCustomer(CustomerVO objCustomer){
this.objCustomer = objCustomer;
public void ejbStore(){
customerName = objCustomer.getName();
customerMail = objCustomer.getMail();
customerType = objCustomer.getType();
HTH
VJ

How to use same transaction when calling CMP entity beans and DAO (JDBC)

We are currently using Weblogic 8.1 SP2 with an Oracle 10g database (using XA thin and non-XA drivers).
We have a session bean that invokes an entity bean and a DAO (data access object pattern) in order to add data in 2 separate tables (account and history). Rows are added to the first (account) table using a CMP Entity bean while inserts are done in the 2nd (history) table using a DAO. Here is some pseudo code:
addHistorySessionBean (trans-attribute="Required")
begin
Step #1 - call addAccountEntityBean (trans- attribute="Required")
Step #2 - call addHistoryDAO (get datasource, connection)
end
The 2nd table (history) has a foreign key constraint to ensure that the corresponding key exists in the first (account) table. Unfortunately, DAO inserts on the 2nd (history) table fail with a foreign key constraint violation (INTEGRITY CONSTRAINT VIOLATION - PARENT KEY NOT FOUND!) since they cannot see the row added to the 1st (account) table in step #1 by the CMP entity bean.
How does one ensure that all this is done in a single transaction ? It appears that the app server creates two seperate transactions (one for the session bean facade and the entity bean and a 2nd transaction (when we retrieve a connection using the same data source JNDI name) for the DAO.
A post on server side suggested using a "<resource-ref>" in the session bean to tie the two potentially separate transactions together, but that does not work for us. However, I am not sure if we are doing that correctly. After we define the resource ref in the session facade bean, do we use the resource ref "name" attribute to lookup the datasource or do we still lookup the datasource by JNDI name ? Do we need to define the resource-ref tag in the entity bean also ?
Does Weblogic allow using a single transaction for this type of a scenario ? How does one specify within Weblogic that the same transaction should be utilized by the entity bean and any subsequent DAOs?
People have also suggested that we defer constraint checking until the transaction(s) are committed but that sounds like a work acount without addressing this issue. Would postponing the constraint checking in Oracle cause any additional overhead ?
Any suggestions with specific examples or documentation on how to address this issue will be gratefully appreciated.

Thanks for your suggestion. Unfortunately, this does not work since it appears that there are 2 separate transactions going on here. One, the original one initiated by the session bean and used by the entity bean and the other initiated by the DAO. Any other ideas appreciated.
Hi,
Try setting the delay-database-inserts tag to
ejbCreate in RDBMS descriptor file.
http://bernal/stage/wls/docs81/ejb/DDreference-cmp-jar
.html#1113981
vasanthi ramesh

Error while using sybase trigger with the CMP entity bean,ejb version 2.1

Hi All,
I am using ejb version 2.1 and using entity bean (Transaction required) ,i am trying to update data in sybase(ver 12.3) database table
I am using session bean(Transaction required) to update the multiple entity beans in a while loop.It is working fine .But when i am trying to run it with the trigger which updates multiple tables in different sybase databases on update of each entity.Then it throws NoSuchEntityException and it rollback the whole transaction.
My trigger has only few simple update statements and the trigger runs fine without my CMP entity bean.is the CMP does not support the update triggers in sybase or is it the problem with the transaction.
Please help
Thanks
Anshu

If you can have a look at a cmp example in the samples that ship with the server. My guess is that the weblogic-ejb-jar.xml file is missing the <persistence-use> element which for 810 would look like:
<persistence>
<persistence-use>
<type-identifier>WebLogic_CMP_RDBMS</type-identifier>
<type-version>7.0</type-version>
<type-storage>META-INF/weblogic-cmp-rdbms-jar.xml</type-storage>
</persistence-use>
</persistence>
I seem to recall that the elements might be slightly different in structure for the wls700 version of the DTD, so please check that (I cannot, I'm at home and don't have everything here).
Give that a try and see if it doesn't solve your compilation failure.
Also, the compilation should not be throwing a null pointer exception in a case like that, I consider that to be a bug.
-thorick

Bad Performance/OutOfMemory Error in CMP Entity Bean with Large DB

Hello:
I have an CMP Entity deployed on WLS 7.0
The entity bean maps to a table that has 97,480 records.
It has a finder: findAll() -- SELECT OBJECT(e) FROM Equipment e
I have a JSP client that invokes the findALL()
The performance is very poor ~ 150 seconds just to perform the findAll() - (Benchmark
from within the JSP code)
If more than one simultaneous call is made then I get outOfMemory Error.
WLS is started with max memory of 512MB
EJB is deployed with <max-beans-in-cache>100000</max-beans-in-cache>
(without max-beans-in-cache directive the performance is worse)
Is there any documentation available to help us in deploying CMP Entity Beans
with very large number of records (instances) ?
Any help is greatly appreciated.
Regards
Rajan

Hi
You should use a Select Method, it does support cursors.
Or a Home Select Method combination.
Regards
Thomas
WLS is started with max memory of 512MB
EJB is deployed with <max-beans-in-cache>100000</max-beans-in-cache>>
(without max-beans-in-cache directive the performance is worse)>
Is there any documentation available to help us in deploying CMP
Entity Beans with very large number of records (instances) ? Any help
is greatly appreciated.>
Regards>
Rajan>
>
"Rajan Jena" <[email protected]> schrieb im Newsbeitrag
news:3dadd7d1$[email protected]..
>
Hello:
I have an CMP Entity deployed on WLS 7.0
The entity bean maps to a table that has 97,480 records.
It has a finder: findAll() -- SELECT OBJECT(e) FROM Equipment e
I have a JSP client that invokes the findALL()
The performance is very poor ~ 150 seconds just to perform the findAll() -(Benchmark
from within the JSP code)
If more than one simultaneous call is made then I get outOfMemory Error.
WLS is started with max memory of 512MB
EJB is deployed with <max-beans-in-cache>100000</max-beans-in-cache>
(without max-beans-in-cache directive the performance is worse)
Is there any documentation available to help us in deploying CMP EntityBeans
with very large number of records (instances) ?
Any help is greatly appreciated.
Regards
Rajan

CMP Entity Bean with ejb-ql finder methods and INFORMIX database

Hi,
I have some CMP Entity Beans with finder methods defined in ejb-ql. In my ejb-jar, within <entity> definitions I have something like:
    <entity>
      <abstract-schema-name>BeanName</abstract-schema-name>
      <cmp-field><field-name>fieldOne</field-name></cmp-field>
      <cmp-field><field-name>fieldTwo</field-name></cmp-field>
      <query>
        <query-method>
          <method-name>findAll</method-name>
          <method-params></method-params>
        </query-method>
        <ejb-ql>SELECT OBJECT(o) FROM BeanName o</ejb-ql>
      </query>
    <entity>
And in persistent.xml:
<db-properties>
     <data-source-name>datasource_name</data-source-name>
</db-properties>
<entity-bean>
     <ejb-name>BeanName</ejb-name>
     <table-name>table_name</table-name>
     <field-map key-type="NoKey">
     <field-name>fieldOne</field-name>
     <column><column-name>column_one</column-name></column>
      </field-map>
     <field-map key-type="NoKey">
     <field-name>fieldTwo</field-name>
     <column><column-name>column_two</column-name></column>
      </field-map>
      <finder-descriptor>
          <method-name>findAll</method-name>
          <method-params/>
     </finder-descriptor>
Once deployed, on server side, I can found a java source file (with corresponding compiled class file) in path:
j2ee/cluster/server0/apps/companyName/MyEARApp/EJBContainer/temp/temp38837373733/route/to/package/
with names:
BeanName0_0pm.java
BeanName0_0PM.class
and the generated java file contains this code:
public java.util.Enumeration ejbFindAll() throws javax.ejb.FinderException, javax.ejb.EJBException {
    TransactionContext tc = pm.getTransactionContext();
    Connection conn = null;
    PreparedStatement pSt = null;
    ResultSet ejb_rs = null;
    int status = javax.transaction.xa.XAResource.TMSUCCESS;
    try {
      conn = pm.getConnectionForFindMethod();
      pSt = conn.prepareStatement("SELECT \"O\".\"COLUMN_ONE\",\"O\".\"COLUMN_TWO\", FROM \"TABLE_NAME\" \"O\"");
      ejb_rs = pSt.executeQuery();
I'm trying to call this method but it throws a SQLException when preparing the statement.
It seems that Informix does not like this SQL syntax because of upper case names, doble quotes on table alias, or something else.
When editing persistent.xml in netweaver, I can define the element <datasource-vendor> as ORACLE, SAPDB, MS_SQL_SERVER, DB2_UDB_AS400 or DB2_UDB_OS390 but INFORMIX is not an accepted value.
Is there any way to define how this SQL query is build?
Thanks in advance.

The return type of the finder method defined in the remote home interface is either the entity bean's remote interface or a collection of objects implementing the entity bean's remote interface. The return type of the finder method defined in the local home interface is either the entity bean's local interface or a collection of objects implementing the entity bean's local interface

How to manage a XMLType in a CMP Entity Bean

Hi everyone.
Have any of you dealt with a XMLType in a CMP Entity Bean, for instance, the oracle CLOB datatype or directly with XMLType? any of you have tried with a successful result?
What I have to do for creating a CMP if the destination table is going to have a XMLType column. Because I need to Store a very large XML Document.
I will really appreciate.
Thank you
Francisco.

Francisco,
In case you haven't already seen it, perhaps this blog from Debu Panda will help:
http://radio.weblogs.com/0135826/2004/08/11.html#a60
Good Luck,
Avi.

ORA-01407 when removing a CMP Entity Bean with WLS 9.1

Hi all !
I hope you can help me to solve this ?:|
I'm migrating my application from WLS 8.1 SP3 to WLS 9.1.
I'm getting now an SQLException when I try to remove a CMP Entity Bean.
The stacktrace is as follows:
java.sql.SQLException: ORA-01407: cannot update ("USER"."MY_TABLE"."THE_CMR_FIELD") to NULL
     at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:145)
     at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:331)
     at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:288)
     at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:743)
     at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:216)
     at oracle.jdbc.driver.T4CPreparedStatement.executeForRows(T4CPreparedStatement.java:1120)
     at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1278)
     at oracle.jdbc.driver.OraclePreparedStatement.executeInternal(OraclePreparedStatement.java:3415)
     at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePreparedStatement.java:3498)
     at weblogic.jdbc.wrapper.PreparedStatement.executeUpdate(PreparedStatement.java:128)
Of course, I replaced the table and column names above to be more readable ;-)
The table MY_TABLE has a CMR field called THE_CMR_FIELD. The column is not nullable in the database (by the way, it's an Oracle 9i).
Everything is fine under WLS8.1
I tried two different Oracle JDBC drivers (9.2.0.5 and 10.2.0.1.0), but the result is always the same within WLS9.1.
Any ideas or suggestions (or even questions) are more than welcome!
Thanks
Eric

What's even more weird is that I have what seams to be the same problem on Weblogic 6.1 (SP4).
Here's the stacktrace:
<pre>
javax.ejb.EJBException:
Start server side stack trace:
java.sql.SQLException: ORA-01407: cannot update ("SCHEMA"."TIM_WP_DAY_CORE_PERIODS"."TWD_ID") to NULL
     at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
     at oracle.jdbc.ttc7.TTIoer.processError(TTIoer.java:289)
     at oracle.jdbc.ttc7.Oall7.receive(Oall7.java:573)
     at oracle.jdbc.ttc7.TTC7Protocol.doOall7(TTC7Protocol.java:1891)
     at oracle.jdbc.ttc7.TTC7Protocol.parseExecuteFetch(TTC7Protocol.java:1093)
     at oracle.jdbc.driver.OracleStatement.executeNonQuery(OracleStatement.java:2047)
     at oracle.jdbc.driver.OracleStatement.doExecuteOther(OracleStatement.java:1940)
     at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:2709)
     at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePreparedStatement.java:589)
     at com.p6spy.engine.logging.P6LogPreparedStatement.executeUpdate(P6LogPreparedStatement.java:183)
     at weblogic.jdbc.jts.Statement.executeUpdate(Statement.java:503)
     at package.WorkPatternDayCorePeriods_vd9y46__WebLogic_CMP_RDBMS.__WL_store(WorkPatternDayCorePeriods_vd9y46__WebLogic_CMP_RDBMS.java:2317)
     at weblogic.ejb20.manager.DBManager.flushModified(DBManager.java:438)
     at weblogic.ejb20.internal.TxManager$TxListener.flushModifiedKeys(TxManager.java:552)
     at weblogic.ejb20.internal.TxManager.flushModifiedBeans(TxManager.java:298)
     at weblogic.ejb20.manager.BaseEntityManager.flushModifiedBeans(BaseEntityManager.java:1246)
     at weblogic.ejb20.cmp.rdbms.RDBMSPersistenceManager.flushModifiedBeans(RDBMSPersistenceManager.java:1106)
     at weblogic.ejb20.manager.BaseEntityManager.cascadeDeleteRemove(BaseEntityManager.java:840)
     at weblogic.ejb20.manager.DBManager.remove(DBManager.java:656)
     at weblogic.ejb20.internal.EntityEJBLocalObject.remove(EntityEJBLocalObject.java:97)
     at package.WorkPatternDayCorePeriodsEJB_vd9y46_ELOImpl.remove(WorkPatternDayCorePeriodsEJB_vd9y46_ELOImpl.java:722)
     at package.PersonWorkPatternBC.removeWorkPatternDay(PersonWorkPatternBC.java:571)
     at package.remove(PersonWorkPatternBC.java:708)
     at package.TimPersonCalendarServiceEJB.removeWorkPattern(TimPersonCalendarServiceEJB.java:140)
</pre>
In fact I have this setup:
<pre>
workpattern 1..n workpatternday -| 1..n dayperiod
| 1..n daycoreperiod
</pre>
And before 'ejbRemove'ing the workpattern I first remove the days and before that the periods and core periods.
I start with the periods and instead of removing them in the DB he tries to update the FK to the day with '' (p6spy result).
When I remove the not null constraint on the foreign key everything passes to the day where the workpatternId cannot be set to null.
He does not throw errors on the coreperiod (where the not null constraint to day is still present).
When I invert the sequence of deleting
(first the core periods then the 'regular' periods) he complains about the dayId on the core periods table.
So it's completely absurd :S
I hope weblogic 8.1 might solve this problem as this development code is still to be migrated to 8.1 before going in production...
I would just like to know what's wrong. There are other places with just about the same relationships (CMR and DB) where he does not complain...

Where to see the SQL statement that CMP Entity bean excuted?

hi, I'm wondering where I can find the SQL that a CMP entity bean executed in a transaction?
thank you!

You can do it in many ways. If you are using eclipse then using eclipse
plugins for weblogic you van do it. I have heard that in weblogic workshop
also you can do it. If the above do doesn;t solves your problem then check
this out.
http://www.p6spy.com/documentation/install.htm
Hope that helps.
<Xin Zhuang> wrote in message news:[email protected]..
hi, I'm wondering where I can find the SQL that a CMP entity bean executed
in a transaction?
thank you!

CMP entity bean update after database update

I'm new to JDeveloper and J2EE. Since JDev 10.1.3 is now production software I finally got started with it. Everything was quite simple to achieve however I have one problem.
My current setup is faily easy. I have a statelss session bean and a CMP entity bean using TopLink (both EJB 2.1). Getting them both created went smooth and having the two talk was as easy as pie thanks to Jdev.
The problem I have is with the entity bean. I'm using a custom finder method to retrieve records using non-PK fields. This works like a charm and I'm getting the data I need. But when I update the data in the database (OracleXE) and I rerun the client I get the old data. The only way for me to get new data is to restart the embedded OC4J server in JDev.
How can I have the entity bean updated by changes in the database?

Thanks Avi!
I spent some time with the documentation and I see I can configure the cache. However how to do this is not clear to me. I have the impression that most of it relates to BMP entity beans.
Apparantly there is a DoNotCheckCache method I can invoke on the query, but I have no idea how to achieve this...
Message was edited by:
Deddiekoel

CMP Entity Beans read database row twice?

Here are two basic questions regarding container managed persistence Entity Beans:
How many database read operations are performed when a remote reference to a CMP Entity Bean is obtained by a client?
Is it correct, that each row is read twice?
For example if a have one row in a database which I want to lookup, AFAIK first the findByPrimaryKey method perfoms a select to lookup the primary key, and then the (container-)ejbLoad method actually reads the row a second time to populate the CMP fields of the bean.
And how often are UPDATE statements performed?
Is a database UPDATE statement performed each time a setXX method is invoked?
Thanks for any help,
Robert

How many database read operations are performed when a
remote reference to a CMP Entity Bean is obtained by a
client?
Is it correct, that each row is read twice?It all depends on the CMP system. A simple system might well hit the database twice, once to validate the primary key and once to load the object's fields. A
smarter system might try to cache the results from the first, so it didn't need to do the second (although this might be a bit dodgy from a transactional point of view).
However, a couple of facts about databases come in here. Firstly, the query to check the primary key doesn't actually need to load any data from the table: it just needs to check that the key exists. Thus, it should be possible to handle this query just using the index, not touching the table itself at all. Secondly, databases do their own caching, so if a row was loaded in the first query, there is a good chance that it would still be around for the second.
And how often are UPDATE statements performed?
Is a database UPDATE statement performed each time a
setXX method is invoked?Under CMP 1.1, UPDATES are typically done at the end of a transaction; if you use container-demarcated transactions, then yes, UPDATES will happen after every call. If the client code sets up its own transaction, then the UPDATE will only happen after several setXXX calls.
This can be a performance problem. A common solution is the use of coarse-grained detail objects:
http://java.sun.com/j2ee/blueprints/sample_application/model/ (section 10.4.1.2)

Use direct JDBC with CMP entity bean in one transaction

I am trying to use direct JDBC call with CMP entity bean within a session
bean method that requires transaction. The problem is that it appears these
are not in the same transaction. When I use the JDBC call, the CMP entity
bean update to the DB has not been committed yet.
We are using Weblogic 5.1 SP6. The DB is Oracle.
What I do for the JDBC is get a new connection from the pool using weblogic
jdbc pool driver.
Any help would be appreciated.
Patrick

Hi. You can do JDBC and invoke CMP EJBs and have this all treated
as one transaction, if your hand-written code explicitly starts
a JTS transaction, then uses the jts driver or a TxDataSource to
get the JDBC connection. Then your code can call transactional
EJBs and their work will be included in the transaction you started.
Assuming the bean work went OK, and your manual JDBC went OK, you
can manually commit the UserTransaction at that time. This is 5.1
talk. For 6.0, with @PC, this may be even easier...
Joe
Patrick Shen wrote:
>
But if I do that, then they would not be in the same transaction anymore.
Is there any way to use JDBC with CMP Entity bean in the same transaction?
Patrick
"L'artiste" <[email protected]> wrote in message
news:[email protected]...
Are you calling all the CMP create in the session Bean ? If so, beforeyou
make the JDBC call from the session bean, the CMP in 2. should commit. Try
to set its attribute to TX_REQUIRES_NEW. This way, the calling client will
block until this transaction is done (committed) before the execution
continues. There might be some overhead involved in doing so if you are
anticipating a lot of users.
"Patrick Shen" <[email protected]> wrote in message
news:[email protected]...
What I am trying to do is:
In a Session bean method -
1. create a new CMP entity bean (a new row in DB table)
2. create another new CMP entity bean that uses previous bean as foreignkey
3. use JDBC to update the row just created
And all these 3 calls have to be in one transaction.
Thanks,
Patrick
"L'artiste" <[email protected]> wrote in message
news:[email protected]...
Can you give a little bit more information?
Do you have methods in your session bean that creates this CMP entitybeans?
It looks like
you might wanna try to change the isolation level to
TRANSACTION_READ_COMITTED
to preven dirty_read.
"Patrick Shen" <[email protected]> wrote in message
news:[email protected]...
I am trying to use direct JDBC call with CMP entity bean within a
session
bean method that requires transaction. The problem is that it
appears
these
are not in the same transaction. When I use the JDBC call, the CMP
entity
bean update to the DB has not been committed yet.
We are using Weblogic 5.1 SP6. The DB is Oracle.
What I do for the JDBC is get a new connection from the pool usingweblogic
jdbc pool driver.
Any help would be appreciated.
Patrick
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Re: Using CMP Entity Beans in Business Logic

One thing that you need to answer here is
"In the queries for the subsequent tables, in the where clause will the fields be the same and is it that only their values change?"
In the above is true I'd suggest going for a CMP as you save a lot of coding and transaction management out there.
If the above is not true and even the fields in the where clause change on fly there is no way that you can go for CMP. You will have to go for BMP.
Hope this helps decide

Hi.
You might try posting this message to the weblogic.developer.interest.cmp
newsgroup.
Regards,
Michael
Pankaj wrote:
Hi,
I have made a few CMP entity beans which are mapped to single tables in
Oracle 8i.
Create and remove of a row is working fine via the entity bean.
But when i try to update a particular row it is not happening.
The steps that I am doing are :
1. call home.findByPrimaryKey(instance of the Primary key class)
2. remote.setXXX for the field to be modified.
when i invoke setXXX() method the methods are called in the following
sequence : ejbLoad() > setXXX() > ejbStore()
but the data is not getting persisted in the Data base ....in the column it
is still the same old data.
is it something to do with a commit call or some configuration issue??....
Is there any other step to be called
I am using Weblogic 6.1 Sp2
Any help will be appreciated....This is really urgent...
Thank you,
Pankaj--
Michael Young
Developer Relations Engineer
BEA Support

Caching CMP entity beans in a Weblogic cluster

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