Return-Path: Delivered-To: apmail-incubator-geronimo-dev-archive@incubator.apache.org Received: (qmail 36296 invoked by uid 500); 8 Aug 2003 03:19:27 -0000 Mailing-List: contact geronimo-dev-help@incubator.apache.org; run by ezmlm Precedence: bulk list-help: list-unsubscribe: list-post: Delivered-To: mailing list geronimo-dev@incubator.apache.org Received: (qmail 36283 invoked from network); 8 Aug 2003 03:19:27 -0000 Received: from h020.c001.snv.cp.net (HELO c001.snv.cp.net) (209.228.32.134) by daedalus.apache.org with SMTP; 8 Aug 2003 03:19:27 -0000 Received: (cpmta 15581 invoked from network); 7 Aug 2003 20:19:36 -0700 Received: from 68.107.221.139 (HELO downinthedesert.com) by smtp.register-admin.com (209.228.32.134) with SMTP; 7 Aug 2003 20:19:36 -0700 X-Sent: 8 Aug 2003 03:19:36 GMT Message-ID: <3F3316E3.4070501@downinthedesert.com> Date: Thu, 07 Aug 2003 20:20:03 -0700 From: jcd Reply-To: jcd@downinthedesert.com Organization: Down in the Desert, Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.1) Gecko/20020830 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Chris Rauschuber CC: geronimo-dev@incubator.apache.org Subject: Re: [persistence] Some thoughts regarding CMP and JDO References: <20030808030921.27075.qmail@web13006.mail.yahoo.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Rating: daedalus.apache.org 1.6.2 0/1000/N Aren't we, in some respects, getting a bit overzealous about the Persistence Tier? Let's focus on getting the EJB life-cycle management and transaction hierarchies dialed and designed. Why not gear efforts to the production of a solid BMP implementation with Connection, Datasource, and Transaction management - get that dialed and define a pluggable OPTIONALthird-party persistence interface. What is the consensus out there regarding the use of BMP? Is there any desire to have the ability to 'unplug' any/all container persistence services in exchange for a smaller footprint, lighter weight implementation? Concentrating efforts on the basic EJB container services might well prove to be a quicker track to a stable, performing implementation that can be extended to accommodate the various persistence approaches at a later time. It is my feeling that this approach could postpone much of the inevitable analysis paralysis that often accompanies 'The Persistence Debate." Meanwhile, back at the ranch, Geronimo is beating his drums to early release victory. Best, John C. Dale Professional Services Compuware Chris Rauschuber wrote: >Hello Dain and Geronimo, > >If there is a need for persistence to LDAP, please take a look at >http://jellyfish.sourceforge.net, a JDO-like persistence mechanism for >LDAP. We'd be happy to coordinate with you if you're interested. > >Regards, >Chris Rauschuber > > > >>>Dain Sundstrom wrote: >>> >>> >>> >>>>Hello Thomas (and the rest of the OJB team), >>>> >>>>Jeremy Boynes and I (and a few others) wrote the CMP 2.0 >>>>implementation in JBoss, and we have been working on the >>>> >>>> >>persistence >> >> >>>>code in the initial Geronimo code base. >>>> >>>>There is some code right now (a compiler and sql generator) and a >>>>fairly extensive design, but it looks like we have similar >>>> >>>> >>designs. >> >> >>>>The design is fairly simple from the high level. We will support >>>>several front end layers simultaneously at runtime (CMP, JDO, >>>> >>>> >>maybe >> >> >>>>Hibernate, heck maybe SQL). The job of the front end layer is to >>>> >>>> >>>>handle the life-cycle and callbacks required by the related >>>>specification, but all real work will be delegated to a >>>> >>>> >>centralized >> >> >>>>persistence service. This persistence service handles caching, >>>>locking, versioning, clustering and so on. When persistence >>>> >>>> >>service >> >> >>>>actually needs to manipulate data it delegates to a store manager >>>>service. The target initial store managers include SQL 92, SQL >>>> >>>> >>99, >> >> >>>>Oracle (which is not really SQL), file based (XML maybe), and we >>>> >>>> >>have >> >> >>>>plans to add LDAP, clustered database layer and some legacy >>>> >>>> >>systems. >> >> >>>>The following ASCI picture sums this up (if it comes through): >>>> >>>> --------------- >>>>CMP ----------> | | ------> SQL >>>>JDP ----------> | persistence | ------> Oracle >>>>Hibernate ----> | manager | ------> LDAP >>>> | | ------> CICS (whatever) >>>> --------------- >>>> >>>>Now the persistence manager has a huge job, so it is broken down >>>> >>>> >>into >> >> >>>>plugins for caching, locking and so on, which effectively makes >>>> >>>> >>the >> >> >>>>persistence manager just a coordinator of the plugins. >>>> >>>>Anyway, this is getting a little too technical for right now, >>>>considering the initial code doesn't even have Entity beans. From >>>> >>>> >>>>what I have seen, we have a similar vision, and I think we should >>>>talk about merging our efforts into a common persistence engine >>>>(maybe we can even get Gavin and the Hibernate team to sync up >>>> >>>> >>with >> >> >>>>us). I think it would be really positive for Java to at least >>>> >>>> >>have >> >> >>>>all of us at least talking so our systems can play well together, >>>> >>>> >>but >> >> >>>>if we joined forces.... :D >>>> >>>>-dain >>>> >>>> >>>> >>>> > > >__________________________________ >Do you Yahoo!? >Yahoo! SiteBuilder - Free, easy-to-use web site design software >http://sitebuilder.yahoo.com > > > >