Agenda

• Towards a Web Object Model, Frank Manola, Object Services and Consulting
• Experience with iM, a Componentized Web Infrastructure, Pete Bonham, Director R&D/CTO Tektonic Software
• Internet, Intranet, Extranet, Web: How should I Deploy my CORBA Application, Imran Sayeed, CTO, NetNumina Solutions
• HTTP-NG Briefing, Larry Smith, IBM
• Brainstorm on OMG + Java Relationship, led by Craig Thompson, Object Services and Consulting
• Working Session on Object Transfer and Manipulation (OTAM), led by Shel Sutton, The MITRE Corporation
• CVW, Shel Sutton, The MITRE Corporation
• Next Meeting Agenda

Attendees

Towards a Web Object Model, Frank Manola, Object Services and Consulting

Thesis: There is a need to further integrate web and object technology. The complexity of applications that the web is being applied to is increasing and there is beginning to be overlap with OMG. OMA provides a useful architecture. The notion that the web is a simple distributed object system is not new: URLs provide OIDs, pages as state, behavior provided by HTTP servers and scripting languages on client and server side. A number of efforts have tried to amplify this integration. Object technology is a convenient language for extending the web.

Fundamental components of any object model requires data structures that can represent state and a means of associating behavior. Mapping this to the web, we need to gather the data/pages and associated relevant code. Java provides one means for doing all this. Two approaches: do it all in Java or beef up parts of the web infrastructure.

W3C is doing relevant work.

• XML is an SGML subset. It is increasingly built into IE. Lots of end user interest. Gave examples. Tags have application semantics, not necessarily presentation semantics, which is separately specified. XML-Link, XML Stylesheets, XML Namespace Facility (keep separate or mix the namespaces). See http://www.w3.org/XML/
• PICS - Platform for Internet Content Selection - for defining content rating by various third party rating services. Implemented as an http enhancement. Ratings do not have to be embedded in the document. PICS-NG is like PICS but uses XML so you can define your own tags. Some other XML data models are XML-Data (Microsoft), Meta Content Format (Netscape), and Channel Definition Format.
• RDF - Resource Description Format - a standard way to represent metadata. Many ways to associate assertions and resources. Can reify properties so they can be assigned properties. RDF has defined serialization, assertions, and structure.
• DOM - Document Object Model - provides an OO API, don't have to parse text. Client can manipulate objects from client. DOM plug-ins. Class hierarchy rooted at document with HTML and XML subtypes. You get a generic interface. A purchase order is a generic object.
• HTML supports OBJECT tag to generalize applets.

Final observations -- you can support many kinds of object models using these mechanisms. All the representations have a predicate logic formulation. Reification is important. Object logics provide a way to define query languages over these structures.

Experience with iM, A Componentized Web Infrastructure, Pete Bonham, Director R&D/CTO, Tektonic Software

Notes on presentation:  Tektonic is a business unit of Tandem. Marchitecture: Tektonic does high performance IPC (fastest or close to it). Krypton ORB on top. Distilling products off of iM. Started down this path 4 years ago. Architecture must be extensible and scaleable - adapter, gateway, transformers. (Note: start with clean architecture and then warts appear which are secondary architectural abstractions). Few adapters, many gateways. Services are protocol independent, stateless, not all services you need are in your architectural space so gateways are critical. They quickly made some design decisions that became irrevocable. No co-location exploitation. Scaleable and replicable components. Parse headers into contexts of attribute value pairs. All components in their architecture have IDL interfaces so they can run in different environments. You need different TCP components because they must be retargetable. Showed the stream interface using get/put. Partners can extend the architecture via replacing modules and server side scripting.

Lessons learned: coarse-grained asynchronous components yields an architecture and implement. Might have reached a limit in componentry. The humble stream still as legs. The component approach is best. Context is hard - seems to be an optimization problem. Not so sure you can get top performance w/o taking performance into account. CM, management, alerts is a big resource sink. Need canonical approach to configuratiion and alerts. Having more success via iscript as opposed to IDL.

Guesses and beliefs. Product will die if it does not form a solid community. Not clear whose component problem it is in multi-component vendor environments. Best component may be too heavy weight for someone else. Request/response might need a dialog. Throughout the lifecycle, enormous productivity gains are still possible.

Internet, Intranet, Extranet, Web: How should I deploy my CORBA Application, Imran Sayeed, CTO, NetNumina Solutions

• Security
• Firewall support
• Running fully functional CORBA components in Web browsers
• Efficient downloading of CORBA components

Notes on presentation:  NetNumina moves business critical applications to IDL and the web. What does web-enabling of an application mean? The application has a web browser presentation layer. Use Java, JavaScript, XML, … Use the web because it is omnipresent. CORBA is the only standards-based distributed object infrastructure available in 100% pure Java. Much faster to download Java ORB clients on Netscape and saves money on runtime licenses since its built in. Can be bundled into jar or cab files for quicker downloads. CORBA vendors are bundling new capabilities as jar files.

Internet-enabling is having apps available across firewalls. Extranet traverses some walls Requires firewall, WANs, security (authentication, authorization, data encryption, non-repudiation, integrating w existing enterprise security). Intranet is inside the company-clients want superior user interface and GUI controls.

CORBA provides support for Java. COM/CORBA bridge. CORBA services like event, persistence, trader.

NetWeaver is a CORBA-based product that has CORBA clients that talk SSL into web server that talks to CORBA, DCOM, DCE.

HTTP-NG Briefing, Larry Smith, IBM

The World Wide Web Consortium (W3C, w3.org) initiates projects via briefing packages. HTTP-NG is one such package. Two subprojects: web characterization group and protocol design group.

The Web Characterization Working Group (chaired by Jim Pitkow) is working on requirements, caching, hot spots, behavior of a high performance web. They are trying to get good metrics on the health of the web and traffic patterns.

The Protocol Design Working Group (chaired by Jim Gettys) is testing the hypothesis "Can a generic distributed object system be used as the foundation of the Web?" The effort is tied into IETF. Other key people are Bill Janssen, Henrik Nielsen, and Mike Spreitzer. Will be related via RFP and IIOP at the transport layer. Xerox ILU is being used for prototyping.

• client side protocol stack: transport - compression - … - browser
• server side protocol stack: transport - …

Brainstorm on OMG Java Relationship, Craig Thompson, Object Services and Consulting, Inc.

(a) replace IDL with Java - nobody is suggesting this, are they?
(b) allow specs with interfaces in Java in place of IDL to be submitted
(c) encourage standard mappings of standard OMG specs to Java using the IDL-Java mapping
(d) have OMG involved in some way in the Sun Java PAS
(e) other ideas

We briefly discussed a few of the alternatives listed above in the abstract as well as a systematic replacement of dusty OMG specs like Trader, Query Service and others that have never been commercially implemented. The discussion was intense and spirited.

Action Item. At the Salt Lake City meeting, we will have a half day morning session on OMG + Java relationship. In between, Craig Thompson will issue a call for position statements (which may lead to email discussions).

Object Transfer and Manipulation (OTAM), Shel Sutton, The MITRE Corporation

Discussion. Shel handed out a White Paper on OTAM (internet/97-12-05) and went over it. Mike Bigrigg (CMU, bigrigg@cs.cmu.edu) volunteered to be document editor. Some work assignments were made or reconfirmed. Expect more progress at the next meeting.

CVW, Shel Sutton, The MITRE Corporation

Next Meeting Plan