Setting transaction isolation level in a session bean

Hi all!
In a stateless session bean (EJB3) with container managed transactions I need to set the transaction isolation level to SERIALIZABLE.
The idea is to prevent lost update on database when multiple accesses occur concurrently.
Thanks in advance for your patience,
Tommaso

Similar Messages

Setting transaction isolation level on a replicated server stored procedure

I have a SQL server that has replication turned onto to another server which is our reporting server. Replication is real-time (or close to it). On the report server I have a stored procedure that runs from a SRS report. My question is it possible or advisable
or does it even make sense to set the "SET TRANSACTION ISOLATION LEVEL READ COMMITTED" on at the beginning of the stored procedure which selects data from the reporting server database? Is it possible for uncommitted data on the OLTP side of the
house to be replicated before it is committed? We are having data issues with a report and have exhausted all options and was wondering if dirty data maybe the issue since the same parameters work for a report 1 sec and then next it doesnt.

Only committed transactions are replicated to the subscriber. But it is possible for the report to see dirty data if running in READ UNCOMMITTED or NOLOCK. You should run your reports in READ COMMITTED or SNAPSHOT isolation , and your replication
subscriber should be configured with READ COMMITTED SNAPSHOT ISLOATION eg
alter database MySubscriber set allow_snapshot_isolation on;
alter database MySubscriber set read_committed_snapshot on;
as recommended here
Enhance General Replication Performance.
David
David http://blogs.msdn.com/b/dbrowne/

How to set transaction isolation level for a method in a Local Interface

 By reference at:
 http://e-docs.bea.com/wls/docs61/ejb/reference.html#1071267,
 the value for method-intf can only be "Remote" or "Home".
 My question is--
 How to set transaction isolation level for a method inside a Local Interface or
 Local_Home Interface?
 Thanks.
 Xing


I'd try 6.1SP2. I'm pretty sure this works now.
 -- Rob
 Xing wrote:
 > I tried "Local", but got an error when deploying the EJB jar, saying that only
 > "Remote" or "Home" is allowed.
 >
 > Any idea?
 >
 > Xing
 >
 > Rob Woollen <[email protected]> wrote:
 > >
 > >
 > >Use LocalHome or Local.
 > >
 > >-- Rob
 > >
 > >Xing wrote:
 > >
 > >> By reference at:
 > >> http://e-docs.bea.com/wls/docs61/ejb/reference.html#1071267,
 > >> the value for method-intf can only be "Remote" or "Home".
 > >>
 > >> My question is--
 > >>
 > >> How to set transaction isolation level for a method inside a Local
 > >Interface or
 > >> Local_Home Interface?
 > >>
 > >> Thanks.
 > >>
 > >> Xing
 > >
 > >--
 > >
 > >----------------------------------------------------------------------
 > >
 > >AVAILABLE NOW!: Building J2EE Applications & BEA WebLogic Server
 > >
 > >by Michael Girdley, Rob Woollen, and Sandra Emerson
 > >
 > >http://learnWebLogic.com
 > >
 > >
 > >
 > >
 > ><!doctype html public "-//w3c//dtd html 4.0 transitional//en">
 > ><html>
 > >Use LocalHome or Local.
 > >-- Rob
 > >Xing wrote:
 > ><blockquote TYPE=CITE>By reference at:
 > > http://e-docs.bea.com/wls/docs61/ejb/reference.html#1071267,
 > > the value for method-intf can only be "Remote" or "Home".
 > >My question is--
 > >How to set transaction isolation level for a method inside a Local
 > >Interface
 > >or
 > > Local_Home Interface?
 > >Thanks.
 > >Xing</blockquote>
 > >
 > ><pre>--
 > >
 > >----------------------------------------------------------------------
 > >
 > >AVAILABLE NOW!: Building J2EE Applications & BEA WebLogic Server
 > >
 > >by Michael Girdley, Rob Woollen, and Sandra Emerson
 > >
 > >http://learnWebLogic.com</pre>
 > > </html>
 > >
 > >
 AVAILABLE NOW!: Building J2EE Applications & BEA WebLogic Server
 by Michael Girdley, Rob Woollen, and Sandra Emerson
 http://learnWebLogic.com
 [att1.html]

Setting transaction isolation level in Weblogic 5.1

 Hi,
 I'm using Weblogic server5.1 and i'm trying to set the isolation level on one
 of my session bean. Below is the code :
 <weblogic-ejb-jar>
 <weblogic-enterprise-bean>
 <ejb-name>chargeMgr</ejb-name>
 <jndi-name>chargeMgr</jndi-name>
 <transaction-isolation>
 <isolation-level>Serializable</isolation-level>
 <method>
 <ejb-name>chargeMgr</ejb-name>
 <method-intf>Remote</method-intf>
 <method-name>*</method-name>
 </method>
 </transaction-isolation>
 </weblogic-enterprise-bean>
 </weblogic-ejb-jar>
 I have checked the syntax against the weblogic documentation.
 However, when i try to jar the beans up into the jar file (weblogic.ejbc), it
 give me the following error :
 org.xml.sax.SAXParseException: Element "weblogic-enterprise-bean" allows no further
 input; "transaction-isolation" is not allowed.
 Can anyone help?
 Regards.


yes, only in weblogic-ejb-jar.xml , and you can see that from the DTD
 source.
 thanks
 Yu
 "cw lee" <[email protected]> wrote in message
 news:[email protected]...
 >
 > thanks for ur advice.
 >
 > one thing i forgot to mention is that the isolation-level was specified in
 weblogic-ejb-jar.xml.
 > Do u mean that it must be placed in weblogic-cmp-rdbms-jar.xml and not
 weblogic-ejb-jar.xml
 > ?
 >
 > Are the codes u suggested to be in weblogic-ejb-jar.xml or
 weblogic-cmp-rdbms-jar.xml
 > ?
 >
 > Regards.
 >
 >
 >
 > "Yu Tian" <[email protected]> wrote:
 > >the right name for Seriealizable should be: TRANSACTION_SERIALIZABLE.
 > >so the
 > >DD looks like:
 > >
 > ><?xml version="1.0"?>
 > >
 > ><!DOCTYPE weblogic-ejb-jar PUBLIC '-//BEA Systems, Inc.//DTD WebLogic
 > >5.1.0
 > >EJB//EN' 'http://www.bea.com/servers/wls510/dtd/weblogic-ejb-jar.dtd'>
 > >
 > ><weblogic-ejb-jar>
 > > <weblogic-enterprise-bean>
 > > <ejb-name>containerManaged</ejb-name>
 > > <caching-descriptor>
 > > <max-beans-in-cache>1000</max-beans-in-cache>
 > > </caching-descriptor>
 > > <persistence-descriptor>
 > > <persistence-type>
 > > <type-identifier>WebLogic_CMP_RDBMS</type-identifier>
 > > <type-version>5.1.0</type-version>
 > > <type-storage>META-INF/weblogic-cmp-rdbms-jar.xml</type-storage>
 > > </persistence-type>
 > > <persistence-use>
 > > <type-identifier>WebLogic_CMP_RDBMS</type-identifier>
 > > <type-version>5.1.0</type-version>
 > > </persistence-use>
 > > </persistence-descriptor>
 > > <jndi-name>containerManaged.AccountHome</jndi-name>
 > > <transaction-isolation>
 > > <isolation-level>TRANSACTION_SERIALIZABLE</isolation-level>
 > > <method>
 > > <ejb-name>containerManaged</ejb-name>
 > > <method-name>*</method-name>
 > > </method>
 > > </transaction-isolation>
 > > </weblogic-enterprise-bean>
 > > </weblogic-ejb-jar>
 > >
 > >Thanks
 > >
 > >Yu
 > >
 > >
 > >"cw lee" <[email protected]> wrote in message
 > >news:[email protected]...
 > >>
 > >> Hi,
 > >>
 > >> I'm using Weblogic server5.1 and i'm trying to set the isolation level
 > >on
 > >one
 > >> of my session bean. Below is the code :
 > >>
 > >> <weblogic-ejb-jar>
 > >> <weblogic-enterprise-bean>
 > >> <ejb-name>chargeMgr</ejb-name>
 > >> <jndi-name>chargeMgr</jndi-name>
 > >> <transaction-isolation>
 > >> <isolation-level>Serializable</isolation-level>
 > >> <method>
 > >> <ejb-name>chargeMgr</ejb-name>
 > >> <method-intf>Remote</method-intf>
 > >> <method-name>*</method-name>
 > >> </method>
 > >> </transaction-isolation>
 > >> </weblogic-enterprise-bean>
 > >> </weblogic-ejb-jar>
 > >>
 > >> I have checked the syntax against the weblogic documentation.
 > >> However, when i try to jar the beans up into the jar file
 (weblogic.ejbc),
 > >it
 > >> give me the following error :
 > >>
 > >> org.xml.sax.SAXParseException: Element "weblogic-enterprise-bean"
 allows
 > >no further
 > >> input; "transaction-isolation" is not allowed.
 > >>
 > >> Can anyone help?
 > >>
 > >> Regards.
 > >>
 > >
 > >
 >

Setting transaction isolation levels in WAS5

I think I'm missing something pretty easy. How can I set the isolation
levels for the containter managed transactions on my beans?
Specifically, I want to set soem lookup methods on my Sessions beans
to TRANSACTION_REPEATABLE_READ. I've already put the
container-transaction blocks in my ejb-jar.xml
Does Websphere 5 have something akin to WebLogic's
weblogic-ejb-jar.xml where you can set additional parameters like
this? Do I have to use a tool like WSAD to specify this? The AAT
doesn't seem to have this option.
Thanks,
James Lynn

Hi Slava, Ryan,
We haven't looked at 8.1 yet since our release cycle wouldn't allow us
to move to 8.1 until at least June anyway, but even if the problems was
fixed there it took BEA support more than 6 months (I opened the case on
Sep 23 2002 and only this week I got the patch that I haven't even tried
to test to see if it works) to issue a patch for such a small problem.
The server would just check if the Oracle XA driver was being used and
no matter what version would just throw an exception if you try to set
the transaction isolation level saying that the feature in the Oracle
8.1.7 driver was broken... (although you might be using 9.x or even a
pre-8.1.7 driver)...
So this is about it.
And Slava, I've tried pushing a case harder only to end up with BEA
support trying to convince me that I was misinterpreting the JDBC spec
when it was not true, so I just gave up. The main goal of BEA support in
all of our experience has been that they don't try to solve the cases
but close them.
That's my and some of my colleagues personal views anyway, you don't
have to share them.
Regards,
Dejan
Slava Imeshev wrote:
Hi Deyan,
Sorry for the delay. Could you give us more details about CR090104?
I've got some feedback in XA area, not sure if it was a related case.
Also, I've never had any problems with weblogic CCE, so you may want
to push your case a little harder.
As per the bold statement - the initial question was about functionality
available in weblogic but not available in websphere - it can't be more
bold :)
Regards,
Slava Imeshev
"Deyan D. Bektchiev" <[email protected]> wrote in message
news:[email protected]...
This is a very bold statement Slava, considering that with Oracle XA
driver you cannot even set the transaction isolation level because of a
Weblogic bug (CR090104 that has been open for more than 6 months
already)...
Dejan
Slava Imeshev wrote:
Hi James,
"James F'jord Lynn" <[email protected]> wrote in message
news:[email protected]...
I think I'm missing something pretty easy. How can I set the isolation
levels for the containter managed transactions on my beans?
Specifically, I want to set soem lookup methods on my Sessions beans
to TRANSACTION_REPEATABLE_READ. I've already put the
container-transaction blocks in my ejb-jar.xml
Does Websphere 5 have something akin to WebLogic's
weblogic-ejb-jar.xml where you can set additional parameters like
this? Do I have to use a tool like WSAD to specify this? The AAT
doesn't seem to have this option.
My guess here is that it's a signal that this is a last chance
for you to abandon WebSphere and return back to WebLogic's
safe harbor.
Regards,
Slava Imeshev

Setting transaction isolation level rises ORA-02089 error

Hello
We have configured a distributed transaction in our application server and
we are using openjpa 1.2.1 and Glassfish application server and Oracle 11g as DB server. Although the default behavior of transaction locking must be optimistic,
it seems that pessimistic locking has been happened.
It is found that Row Lock contention happens in a specific table.
This is the exception :
java.sql.SQLException: ORA-02049: timeout: distributed transaction waiting for lock
Already all the following properties have been set for openjpa.
1. <persistence-unit name="JPXA" transation-type="JTA">
2. <property name="openjpa.TransactionMode" value="managed"/>
You can try a plug-in string to lookup the TM in JNDI (the value is the JNDI name of GlassFish TM as per Google search)
3. <property name="openjpa.ManagedRuntime"
value="jndi(TransactionManagerName=java:appserver/TransactionManager)"/>
Following searching about this locking problem, we found that we should add two more properties for openjpa as listed below.
<property name="openjpa.LockManager" value="version" />
<property name="openjpa.jdbc.TransactionIsolation" value="read-committed" />
but this time by setting the transaction isolation level, we have got another error: org.apache.openjpa.persistence.PersistenceException: ORA-02089: COMMIT is not allowed in a subordinate session.
Thanks for any help.
Regards,
Sargol

Hello
We have configured a distributed transaction in our application server and
we are using openjpa 1.2.1 and Glassfish application server and Oracle 11g as DB server. Although the default behavior of transaction locking must be optimistic,
it seems that pessimistic locking has been happened.
It is found that Row Lock contention happens in a specific table.
This is the exception :
java.sql.SQLException: ORA-02049: timeout: distributed transaction waiting for lock
Already all the following properties have been set for openjpa.
1. <persistence-unit name="JPXA" transation-type="JTA">
2. <property name="openjpa.TransactionMode" value="managed"/>
You can try a plug-in string to lookup the TM in JNDI (the value is the JNDI name of GlassFish TM as per Google search)
3. <property name="openjpa.ManagedRuntime"
value="jndi(TransactionManagerName=java:appserver/TransactionManager)"/>
Following searching about this locking problem, we found that we should add two more properties for openjpa as listed below.
<property name="openjpa.LockManager" value="version" />
<property name="openjpa.jdbc.TransactionIsolation" value="read-committed" />
but this time by setting the transaction isolation level, we have got another error: org.apache.openjpa.persistence.PersistenceException: ORA-02089: COMMIT is not allowed in a subordinate session.
Thanks for any help.
Regards,
Sargol

Setting Transaction isolation level when I'm not in an EJB

 I have a Message Driven Bean (MDB) that is container managed, and its transaction
 isolation is set to TRANSACTION_READ_COMMITTED in weblogic-ejb-jar.xml and that
 seems to work fine. If I look at an entity bean in onMessage which is updated/commited
 outside the transaction I can see the updates no problem.
 Now the problem is this.. inside the onMessage method, the MDB creates a new
 instance of a class. This class starts up its own UserTransaction (using (UserTransaction)new
 InitialContext().lookup("javax.transaction.UserTransaction")) and goes into a
 loop working away. Inside the loop it is inspecting a value on an entity bean.
 The classs never sees any updates to this bean which are made outside this new
 UserTransaction.
 It looks to me that the UserTransaction that the class is getting has a different
 isolation level (serialized?). Is there a way to set the isolation level for
 a UserTransaction?
 Any help would be great!
 lance


 Just a follow up, I think the isolation level is perhaps being set to REPEATABLE_READ,
 since that is what seems to be happening. The value from the first read is maintained
 through subsequent reads in the same transaction.
 lance
 "Lance" <[email protected]> wrote:
 >
 >I have a Message Driven Bean (MDB) that is container managed, and its
 >transaction
 >isolation is set to TRANSACTION_READ_COMMITTED in weblogic-ejb-jar.xml
 >and that
 >seems to work fine. If I look at an entity bean in onMessage which is
 >updated/commited
 >outside the transaction I can see the updates no problem.
 >
 >Now the problem is this.. inside the onMessage method, the MDB creates
 >a new
 >instance of a class. This class starts up its own UserTransaction (using
 >(UserTransaction)new
 >InitialContext().lookup("javax.transaction.UserTransaction")) and goes
 >into a
 >loop working away. Inside the loop it is inspecting a value on an entity
 >bean.
 > The classs never sees any updates to this bean which are made outside
 >this new
 >UserTransaction.
 >
 >It looks to me that the UserTransaction that the class is getting has
 >a different
 >isolation level (serialized?). Is there a way to set the isolation level
 >for
 >a UserTransaction?
 >
 >Any help would be great!
 >
 >lance

Why encounter errors while setting transaction isolation level?

When attempting to set the transaction isolation level within an EJB, I encountered the following exception from the server log:
===========================================================
[#|2006-05-30T15:08:45.906+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.stream.out|_ThreadID=25;|
Enter ejbCreate( 100, Duke, Earl, 0.00 ):|#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.stream.out|_ThreadID=25;|
List of Supported Transaction Isolation Levels: |#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.stream.out|_ThreadID=25;|
TRANSACTION_READ_UNCOMMITTED is supported!|#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.stream.out|_ThreadID=25;|
TRANSACTION_READ_COMMITTED is supported!|#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.stream.out|_ThreadID=25;|
TRANSACTION_REPEATABLE_READ is supported!|#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.stream.out|_ThreadID=25;|
TRANSACTION_SERIALIZABLE is supported!|#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.stream.out|_ThreadID=25;|
1. |#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.stream.out|_ThreadID=25;|Transaction Status: |#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.stream.out|_ThreadID=25;|TRANSACTION_READ_COMMITTED|#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.stream.out|_ThreadID=25;|
con.isReadOnly() = false|#]
[#|2006-05-30T15:08:45.937+0800|WARNING|sun-appserver-pe8.1_02|javax.enterprise.system.stream.err|_ThreadID=25;|
SQLException: java.sql.SQLException: Transaction manager errors. statement not allowed in XA session.|#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.container.ejb|_ThreadID=25;|EJB5018: An exception was thrown during an ejb invocation on [SavingsAccountBean]|#]
[#|2006-05-30T15:08:45.937+0800|INFO|sun-appserver-pe8.1_02|javax.enterprise.system.container.ejb|_ThreadID=25;|
javax.ejb.EJBException: ejbCreate: Unable to connect to database. Transaction manager errors. statement not allowed in XA session.
at SavingsAccountBean.ejbCreate(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at com.sun.enterprise.security.SecurityUtil$2.run(SecurityUtil.java:153)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.enterprise.security.application.EJBSecurityManager.doAsPrivileged(EJBSecurityManager.java:950)
at com.sun.enterprise.security.SecurityUtil.invoke(SecurityUtil.java:158)
at com.sun.ejb.containers.EJBHomeInvocationHandler.invoke(EJBHomeInvocationHandler.java:170)
at $Proxy60.create(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at com.sun.corba.ee.impl.presentation.rmi.ReflectiveTie._invoke(ReflectiveTie.java:123)
at com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatchToServant(CorbaServerRequestDispatcherImpl.java:648)
at com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatch(CorbaServerRequestDispatcherImpl.java:192)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequestRequest(CorbaMessageMediatorImpl.java:1709)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequest(CorbaMessageMediatorImpl.java:1569)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleInput(CorbaMessageMediatorImpl.java:951)
at com.sun.corba.ee.impl.protocol.giopmsgheaders.RequestMessage_1_2.callback(RequestMessage_1_2.java:181)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequest(CorbaMessageMediatorImpl.java:721)
at com.sun.corba.ee.impl.transport.SocketOrChannelConnectionImpl.dispatch(SocketOrChannelConnectionImpl.java:469)
at com.sun.corba.ee.impl.transport.SocketOrChannelConnectionImpl.doWork(SocketOrChannelConnectionImpl.java:1258)
at com.sun.corba.ee.impl.orbutil.threadpool.ThreadPoolImpl$WorkerThread.run(ThreadPoolImpl.java:409)
|#]===========================================================
But from the above log messages, all transcation isolation levels are supported. The relevant source codes are:
/*********************** Database Routines *************************/
private void makeConnection() {
try {
InitialContext ic = new InitialContext();
DataSource ds = ( DataSource )ic.lookup( dbName );
con = ds.getConnection();
DatabaseMetaData dmd = con.getMetaData();
show_supported_trans_levels( dmd );
int status = con.getTransactionIsolation();
System.out.print( "1. " );
disp_tx_status( status );
System.out.println( "con.isReadOnly() = " + con.isReadOnly() );
con.setTransactionIsolation( Connection.TRANSACTION_SERIALIZABLE );
System.out.print( "2. " );
disp_tx_status( status );
} catch( SQLException ex ) {
System.err.println( "SQLException: " + ex.toString() );
throw new EJBException("Unable to connect to database. " +
ex.getMessage());
} catch( NamingException ex ) {
System.err.println( "NamingException: " + ex.toString() );
throw new EJBException("Unable to connect to database. " +
ex.getMessage());
private void disp_tx_status( int status )
System.out.print( "Transaction Status: " );
switch( status )
case( Connection.TRANSACTION_READ_UNCOMMITTED ):
System.out.println( "TRANSACTION_READ_UNCOMMITTED" );
break;
case( Connection.TRANSACTION_READ_COMMITTED ):
System.out.println( "TRANSACTION_READ_COMMITTED" );
break;
case( Connection.TRANSACTION_REPEATABLE_READ ):
System.out.println( "TRANSACTION_REPEATABLE_READ" );
break;
case( Connection.TRANSACTION_SERIALIZABLE ):
System.out.println( "TRANSACTION_SERIALIZABLE" );
break;
case( Connection.TRANSACTION_NONE ):
System.out.println( "TRANSACTION_NONE" );
break;
default:
System.out.println( "UNKNOWN" );
break;
Who can help me?

Try the following forum (about EJB technology)
http://forum.java.sun.com/forum.jspa?forumID=13

Setting transaction isolation level for jDriver Oracle/XA

edocs (http://e-docs.bea.com/wls/docs70/oracle/trxjdbcx.html#1080746) states that,
if using jDriver for Oracle/XA you can not set the transaction isolation level
for a
transaction and that 'Transactions use the transaction isolation level set on
the connection
or the default transaction isolation level for the database'. Does this mean that
you shouldn't try to set it programatically (fair enough) or that you can't set
it in the weblogic deployment descriptor either? Also anybody got any idea what
the default is likely to be if you are using
an Oracle 9iR2 database?

Ian,
The default for Oracle (any version) is ReadCommitted. The only other
isolation level Oracle supports is Serializable but it's implemented in
such a way that you will be allowed to continue until commit time and
only then you might get an exception stating the the access for that
transaction could not be serialized.
I don't know for the jDriver but if you use the Oracle Thin XA driver
even if you set the isolation level in your descriptor you will get an
exception from Weblogic. It is a Weblogic bug and you can contact
[email protected] to get a patch.
Regards,
Dejan
IJ wrote:
edocs (http://e-docs.bea.com/wls/docs70/oracle/trxjdbcx.html#1080746) states that,
if using jDriver for Oracle/XA you can not set the transaction isolation level
for a
transaction and that 'Transactions use the transaction isolation level set on
the connection
or the default transaction isolation level for the database'. Does this mean that
you shouldn't try to set it programatically (fair enough) or that you can't set
it in the weblogic deployment descriptor either? Also anybody got any idea what
the default is likely to be if you are using
an Oracle 9iR2 database?

How to set Transaction isolation level in Weblogic 11g

How do I set the transaction isolation level in Weblogic?
Some references that I found suggest that I have to explicitely state the isolation level in the weblogic-ejb-jar.xml per ejb. If I am using EJB 3.0 why would I need to do that?
Can I set this up as a property in the JDBC datasource setup?
Other application servers like Websphere actually allows for this. Can this be done in Weblogic?
Currently I get the following message if I don't set the isolation level:
Transaction attribute: TX_NOT_SUPPORTED Isolation Level: No Isolation Level Set Tx Timeout: 30000
What seems to be happening is that one update of my transaction is getting rolled back and other consequent calls are failing due to foreign key issues due to the first rollback.
I think the issue is related to the isolation level or the transaction time out being too low.
Any ideas?
BTW: I am using openjpa and using a MS SQLServer. Not sure if that helps the discussion.
Thanks
Edited by: rrivera on Jun 2, 2010 9:18 AM

How do I set the transaction isolation level in Weblogic?
Some references that I found suggest that I have to explicitely state the isolation level in the weblogic-ejb-jar.xml per ejb. If I am using EJB 3.0 why would I need to do that?
Can I set this up as a property in the JDBC datasource setup?
Other application servers like Websphere actually allows for this. Can this be done in Weblogic?
Currently I get the following message if I don't set the isolation level:
Transaction attribute: TX_NOT_SUPPORTED Isolation Level: No Isolation Level Set Tx Timeout: 30000
What seems to be happening is that one update of my transaction is getting rolled back and other consequent calls are failing due to foreign key issues due to the first rollback.
I think the issue is related to the isolation level or the transaction time out being too low.
Any ideas?
BTW: I am using openjpa and using a MS SQLServer. Not sure if that helps the discussion.
Thanks
Edited by: rrivera on Jun 2, 2010 9:18 AM

TX isolation level with stateless session bean in oc4j

Hi All,
I have a stateless session bean with container managed transaction method. This method is called in a Servlet. This method retrieves data from database using 'ejb-location'connection pool and closes the connection inside. Max-connection setting for connection pool is 50
I am facing a problem running servlet multiple times.
When i have the tx_attribute as Supports, it works fine. I can run the servlet hundreds of times
But when i have the tx_attribute as Required, i am able to run servlet only 50 times and further it says 'Max connection limit exceed..unable to get the connection'.
I assume that with 'Required' attribute, it starts a transaction. Why is the transaction not getting completed at end of method? Is transaction hanging somewhere?
I assume that i am closing the connection properly as it is working fine with supports attribute.
When i monitor database, there are only 20 connections.
Why am i seeing this behaviour?
Thanks
srinath

Hi Deepak,
Thanks for your reply.
Actually, our stand alone java application already using spring-hibernate feature. Now we are planning divide our application into modules and deploy each module as ejb beans. As it is already integrated with spring-hibernate we are not using entity beans as of now. My understanding is container uses some default transcation management .so, my question is what are all the configurations needs to be done to let weblogic 10.0 server uses org.springframework.orm.hibernate3.HibernateTransactionManager. I mean, is there are any .xml file in weblogic to configure all these? please reply deepak I am struck here..
Regards,
Rushi.

Transaction Isolation Level for EJB methods

L.S.
I just found out the in OC4J one can not set the transaction isolation level on ejb methods. Moreover one needs to revert to bean managed transaction (manual coding of the ALL transaction logic) to set the isolation level.
On entity beans one can only set the isolation level for the whole bean (not on individual methods), and in session beans there is no way at all to set the isolation level.
This is on shear contract to all other application servers I used before (there one can declaratively set the isolation level for a ejb method, both in session and in entitybean deployment descriptors)
Is it foreseen in a future release to include such a valuable feature will be provided by oc4j?
Note that I was VERY surprised that OC4J could not handle this (I checked the j2ee spec, but admittedly the spec is a little vague about this support and makes it vendor dependent. the j2ee spec does not mandate this, except for CMP entity beans, but includes some suggestions on this ability. But most other application servers implemented the ability)
Regadrs,
Erik

Hello Erik --
I think we met in Perth recently?
Anyway, your information is correct.
We can set the transaction isolation level for each entity bean, at the bean level. We don't have for the specification of method level isolation settings -- I'd be interested to hear how you would like/do use this. What behaviour do you expect to see when a transaction is started that spans multiple methods on a bean with different declared isolation levels.
For session beans, we do not currently have the ability to declaratively specify the isolation level to use for the bean. I know this is not in the forthcoming 904 release, and will to check what is beyond that.
As you point out, this can be done programatically using the Connection.setIsolationLevel() method on any connections you are using from within the session bean.
I'd would like to log an enhancement request for you for this functionality. Can you send me an email at [email protected] and we'll take it offline.
-steve-

Transaction Isolation Levels

Hi Everyboody.
Oracle docs. say that Oracle supports three isolation levels and the isolation level should be set before the transaction begins with the SET TRANSACTION ISOLATION LEVEL .....
Resource: http://otn.oracle.com/docs/products/oracle9i/doc_library/release2/server.920/a96524/c21cnsis.htm#2641
But I find that Oracle 9i supports only two isolation levels, viz. Read Committed and Serializable.
SQL> SET TRANSACTION ISOLATION LEVEL READ ONLY
2 ;
SET TRANSACTION ISOLATION LEVEL READ ONLY
ERROR at line 1:
ORA-02179: valid options: ISOLATION LEVEL { SERIALIZABLE | READ COMMITTED }
Is READ ONLY isolatin level avalilable in Oracle 9i or is there any problem with my SET instruction?
Please help me at the earliest.
Have a nice day!
Kishore

Thanks Dmitry.
It works.
Continuing on the same thread, I would like to know what is the difference between READ COMMITTED and SERIALIZABLE isolation levels?
Thank you for your reply.
Kishore.

Regarding Transaction Isolation Level

We talk about query and update constent problem again. even I don't take it as problem.
I can see this in SAP notes or SAP help:
JDBC Sender Adapter...
· The UPDATE statement must alter exactly those data records that have been selected by the SELECT statement. You can ensure this is the case by using an identical WHERE clause. (See Processing Parameters, SQL Statement for Query, and SQL Statement for Update below).
· Processing can only be performed correctly when the Transaction Isolation Level is set to repeatable_read or serializable.
If I set transaction isolation level as default, then how can I make sure ' default' is repeatable_read or serializable?
Our DB is Informix.

Hey
Please go through the below blog and see if it helps
/people/yining.mao/blog/2006/09/13/tips-and-tutorial-for-sender-jdbc-adapter
Thanks
Aamir

Changing isolation level in a session, is valid please see following situation i have used shapshot.

hi,
--DBCC FREEPROCCACHE
--DBCC DROPCLEANBUFFERS
CREATE TABLE #temp(ID BIGINT NOT NULL)
SET TRANSACTION ISOLATION LEVEL REPEATABLE READ
BEGIN TRAN
INSERT INTO #temp (id) SELECT wid FROM w WHERE ss=1
UPDATE w SET ss =0 WHERE wid IN (SELECT id FROM #Temp)
COMMIT TRAN
IF (EXISTS(SELECT * FROM #temp))
BEGIN
SELECT 'P'
SET TRANSACTION ISOLATION LEVEL SNAPSHOT
BEGIN TRAN
insert into a ( a,b,c)
SELECT a , b ,c FROM w WHERE wid= 104300001201746884
COMMIT TRAN
END
Q1) changin isolation in this way is correct or not?
Q2) why i have chainged isolation is , because
this stmt was updated by other trnsaction also, and i also wanted to udpate it , so i made one repetable read and then snapshot.
UPDATE w SET ss=0 WHERE wid IN (SELECT id FROM #Temp)
DROP TABLE #temp
yours sincerley

http://blogs.msdn.com/b/craigfr/archive/2007/05/16/serializable-vs-snapshot-isolation-level.aspx
Best Regards,Uri Dimant SQL Server MVP,
http://sqlblog.com/blogs/uri_dimant/
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Setting transaction isolation level in a session bean

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