Re: [eclipselink-users] Using Connection Pools across sessions

[Tom Ware <tom.ware@xxxxxxxxxx>]

Hi Rohit,

  I am glad you have been able to find some information about UCP.

  The internal connection pool is currently designed to be used by a single 
session.  Altering it to make it usable by multiple sessions would require a 
significant amount of work and testing - work that is much better done by 
Connection Pool Experts such as the team that develops UCP.

-Tom

Rohit Banga wrote:
>   For (1) below, the following works:
> http://onpersistence.blogspot.com/2008/04/eclipselink-and-datasources.html
>
> On 2/22/2011 12:14 PM, Rohit Banga wrote:
> > Thanks James for clarifying.
> >
> > 1. A third party connection pool might work. So now the question is 
> > how to configure a datasource say, UCP, with eclipselink. I have a 
> > J2SE application. Is there any sample code?
> >
> > 2. It seems a Connection Pool has a reference to a owner session so 
> > that explains why an internal connection pool cannot be shared across 
> > server sessions. I tried the following:
> >
> >         // question in comment
> >
> >         DatabaseLogin login1 = new DatabaseLogin();
> >         // set parameters for login1
> >
> >         DatabaseLogin login2 = new DatabaseLogin();
> >         // set parameters for login2
> >
> >         // actually the parameters for login1 and login2 are the same
> >
> >         ConnectionPool connPool1 = new ConnectionPool();
> >         connPool1.setMinNumberOfConnections(10);
> >         connPool1.setMaxNumberOfConnections(20);
> >         connPool1.setLogin(login1);
> >
> >        // create a *serverSession1* for *configuration 1* using 
> > *login1* and *connPool1*
> >        // create a *serverSession2* for *configuration 2* using 
> > *login2* and *connPool1*
> >        // for both serverSessions, serverSession.login() is executed
> > *
> > *       // ObjectLevelReadQuery with both configurations work, but i 
> > have no way to tell if they are sharing the same connection pool
> >        // if i call logout() on one serverSession, the other is still 
> > accessible and ObjectLevelReadQuery works on this session ... _Why 
> > does it still work?_
> >
> >        // if both serverSessions have the same login object then the 
> > latter configuration persists in both the serverSessions and
> >        // trying to set attributes as per the former configuration 
> > throws an exception
> >
> >
> > 3. Is there a reason for having a reference to the owner session in 
> > the connection pool?
> >
> > Thanks
> > Rohit
> >
> >
> > On 2/16/2011 8:53 PM, James Sutherland wrote:
> > > There is no standard way to share an internal connection pool.
> > > Your best solution is probably to use a third party DataSource, and share
> > > that across your ServerSessions.  If you are using an app server, it will
> > > have its own DataSources, otherwise there are many generic data source
> > > implementations such as Oracle DataSource, Oracle UCP, or c3po, etc.
> > >
> > > You could also create a single ConnectionPool object and explicitly set it
> > > into each of your ServerSessions.  This should work, but note that when you
> > > disconnect one server, it will disconnect the pool.
> > >
> > >
> > >
> > > Rohit Banga-2 wrote:
> > > > Hi All
> > > >
> > > > Consider the following usecase.
> > > > I have a single database for which multiple table configurations have 
> > > > been defined. Each different configuration is associated with a 
> > > > different Server Session. From the server session, I get the entity 
> > > > manager factory which gives me a JPA Dynamic Helper. So far so good, but 
> > > > I want to have a single connection pool and share it among different 
> > > > sessions. If I share the same connection pool object between multiple 
> > > > server session objects, I get some exceptions because of the conflicting 
> > > > configuration definition.
> > > >
> > > > What is the standard way of sharing the connection pool across different 
> > > > sessions?
> > > >
> > > >
> > > > --
> > > > Thanks and Regards
> > > > Rohit Banga
> > > > Member Technical Staff
> > > > Oracle Server Technologies
> > > -----
> > > http://wiki.eclipse.org/User:James.sutherland.oracle.com James Sutherland 
> > > http://www.eclipse.org/eclipselink/
> > >  EclipseLink ,  http://www.oracle.com/technology/products/ias/toplink/
> > > TopLink 
> > > Wiki:  http://wiki.eclipse.org/EclipseLink EclipseLink , 
> > > http://wiki.oracle.com/page/TopLink TopLink 
> > > Forums:  http://forums.oracle.com/forums/forum.jspa?forumID=48 TopLink , 
> > > http://www.nabble.com/EclipseLink-f26430.html EclipseLink 
> > > Book:  http://en.wikibooks.org/wiki/Java_Persistence Java Persistence 
> > > Blog:  http://java-persistence-performance.blogspot.com/ Java Persistence
> > > Performance 
> >
> > --
> > Thanks and Regards
> > Rohit Banga
> > Member Technical Staff
> > Oracle Server Technologies
> >
> >
> > _______________________________________________
> > eclipselink-users mailing list
> > eclipselink-users@xxxxxxxxxxx
> > https://dev.eclipse.org/mailman/listinfo/eclipselink-users
>
> --
> Thanks and Regards
> Rohit Banga
> Member Technical Staff
> Oracle Server Technologies
>
>
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