If you launch 200 concurrent TXs accessing the same entity with an isolation setting different from SERIALIZED, you're bound to get up to 200 entities.
Think about what happens when two concurrent transactions want to access the same LOGICAL Entity Bean(that is, the same PK). There is a property of transactions called Isolation that states that changes being performed by a transaction aren't visible to any other transaction. The actual semantics of the operation are defined by the isolation level that you select for the transaction. Since there's plenty of documentation about these principles that apply to all Transaction Processing systems, I leave it to you to browse the web and your nearest library to find out more about it. However, I don't think that's the reason for the behavior you describe. Here's my take. Weblogic is configured for a pool of 200 Entity Beans. While they're on the pool they're unasigned, that is, they do not have a PK associated with each instance. I'll repeat that: while on the pool, the instances are in an undetermined state- they will be populated with data BEFORE they're passed on to a client, and when released by a client, they will be synched with the DB (commited) BEFORE entering the pool again. Wow, what a ramble... Gotta get some sleep. Juan Pablo Lorandi Chief Software Architect Code Foundry Ltd. [EMAIL PROTECTED] Barberstown, Straffan, Co. Kildare, Ireland. Tel: +353-1-6012050 Fax: +353-1-6012051 Mobile: +353-86-2157900 www.codefoundry.com > -----Original Message----- > From: ravi kakani [mailto:[EMAIL PROTECTED]] > Sent: Monday, April 22, 2002 8:30 PM > To: Juan Pablo Lorandi; [EMAIL PROTECTED] > Subject: Re: Reg number of instances per primary key? > > > Hi Juan, > Thanks for the reply.I am running a test with > only 100 records in the DB and the max cache size is > set to 200.Since there are only 100 records in the DB > shouldn't the weblogic be having only 100 beans > cached(ie one instance per the same primary key)? > > I am finding in the console that 200 beans are > cached!Does this mean that if there are more than one > concurrent transaction with the same entity and the cached > bean for particular primary key is being used by a client > then another instance of the bean with the same primary key > is created to serve another client? Does this mean that the > weblogic server has multiple instances for the same primary key? > > Regards, > Ravi > > > --- Juan Pablo Lorandi <[EMAIL PROTECTED]> wrote: > > I think he means with the SAME primary key. That > > depends on the server > > implementation, and the amount of concurrent TX's > > that interact with the > > SAME entity, the latter of course depends on the > > isolation level > > associated with the EB. > > > > That information is supposed to be concealed by the > > app server(for a > > number of reasons, mainly, scalability issues, and > > TX isolation). You > > should not care about it. > > > > The real question is: Why do you want to know? > > > > Remains curious, > > > > Juan Pablo Lorandi > > Chief Software Architect > > Code Foundry Ltd. > > [EMAIL PROTECTED] > > > > Barberstown, Straffan, Co. Kildare, Ireland. > > Tel: +353-1-6012050 Fax: +353-1-6012051 > > Mobile: +353-86-2157900 > > www.codefoundry.com > > > > > > > -----Original Message----- > > > From: A mailing list for Enterprise JavaBeans > > development > > > [mailto:[EMAIL PROTECTED]] On Behalf Of > > John Bateman > > > Sent: Monday, April 22, 2002 7:24 PM > > > To: [EMAIL PROTECTED] > > > Subject: Re: Reg number of instances per primary > > key? > > > > > > > > > Hi > > > > > > Aren't these number all dependant on the amout > > that the > > > initial pool size is set to? > > > > > > > > > > 1)How many instances of an entity bean(Read > > only) > > > > exist with a given primary key on a single > > server > > > > instance? > > > > > > > > > ============================================================== > > > ============= > > > 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". > > > > > > > > ============================================================== > ============= > > 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". > > > > > __________________________________________________ > Do You Yahoo!? > Yahoo! Games - play chess, backgammon, pool and more http://games.yahoo.com/ =========================================================================== 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".
