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Application ServersG22.3033-011

Session 5 - Main ThemeObject Management Architectures

Dr. Jean-Claude Franchitti

New York UniversityComputer Science Department

Courant Institute of Mathematical Sciences

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Agenda

CORBA-Based Object Management ArchitecturesJava-Based Application ServersWindows ServicesSummaryReadingsAssignment #5

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Summary of Previous Session

CORBAInprise VisiBroker EnvironmentOrbacus

RMI and RMI-IIOPDCOMDOC Platform InteroperabilityWeb-Enabled DOC ApplicationsSummaryReadingsAssignment #4

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Application Servers ArchitecturesApplication Servers for Enhanced HTML (traditional)

a.k.a., Page-Based Application ServersMostly Used to Support Standalone Web Applications

New Generation Page-Based Script-Oriented App. ServersFirst Generation Extensions (e.g., Microsoft IIS with COM+/ASP)Servlet/JSP EnvironmentsXSP EnvironmentCan now be used as front-end to enterprise applicationsHybrid development environments

Distributed Object Computing PlatformsProvide an infrastructure for distributed communications enablingStill need to merge traditional web-oriented computing with objectcomputing

Object Management ArchitecturesDOC Platform + APIs to reusable services and facilities

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Session 4 Addendum I

Distributed Object Computing Platforms

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CORBA ORB Architecture

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CORBA DOC Platform at Work

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CORBA Development Process(pre-CORBA3)

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CORBA Development Process(continued)

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CORBA Development Process(using java2iiop)

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Microsoft Component Object Model(Logical Architecture)

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Session 4 Addendum II

Web-Enabled DOC Platforms

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VisiBroker’s Gatekeeper

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VisiBroker Gatekeeper’s Features

Extends location transparency past the Web server

Gatekeeper acts as a proxy object for all incoming requests from

client applets

Allows callbacks to functions of the server objectsGatekeeper’s proxy objects allows communication back to specificclients

IIOP proxy serverGatekeeper proxys requests and callbacks through a single port on thefirewall

HTTP tunnelingNo additional code required when firewalls do not allow IIOP trafficto pass

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VisiBroker Gatekeeper’s Features(continued)

SSL supportGatekeeper + SSL Pack ensures privacy and integrity of information

Broad flexibility in security configuration (clientcommunication, server callbacks, all communications)Authentication + encryption support

Easy graphical configuration

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VisiBroker’s Gatekeeper

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Part I

CORBA-Based Object Management ArchitecturesAlso See Session 5 Handout on:

“ CORBAServices and CORBAFacilities”“Exploring CORBAServices and CORBFacilities”

“CORBA Activation Service - Portable Object Adapter (POA)”“POA and CORVAL”

“Naming Service - CosNaming”“The CosNaming Module”

and Sub-Topic 2 Presentation on:

“OMA Trading Services”

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OMG Reference Model Architecture

Current and Next Generation OMASee http://www.omg.org/gettingstarted/specintro.htm#OMASee http://www.objs.com/staging/OMG-OMA-NG.html

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Object Services (CORBAservices)

Domain-independent interfaces used by manydistributed object programsProvide basic functionality for distributed objectapplicationsNaming Service: allows clients to find objects basedon namesTrading Service: allows clients to find objects basedon their propertiesOther services: persistence, lifecycle management,security, transactions, event notification, etc.

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Common Facilities (Horizontal CORBAfacilities)Horizontally-oriented interfaces (useful across businessdomains)Oriented towards end-user applications (e.g., userinterface, information mgmt, system mgmt, task mgmt)E.g.: Distributed Document Component Facility (DDCF)

Compound document facility based on OpenDocAllows for presentation and interchange of objectsbased on a document model (e.g., linking ofspreadsheet object into a report document)

Printing, Secure Time, Internationalization, and MobileAgent Facilities

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Information Management Horizontal Facility

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Domain Interfaces (Vertical CORBAfacilities)

Role similar to Object Services and CommonFacilitiesOriented towards specific application domainsE.g., Product Data Management (PDM) Enablers forthe manufacturing domainOther possibilities in the telecommunications,medical, and financial domains

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Application Interfaces

Custom interfaces developed for a given applicationNot standardizedMight become candidates for future OMGstandardization

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CORBA Activation Service(server registration)

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CORBA Activation Service(client request)

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Persistence Service

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Transaction Service

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New in Corba 3

Component Model (CCM)Quality-of-service controlMessaging invocation modelTightened integration with the InternetPOA (Portable Object Adapter)EJB and Java supportOMG specifications for analysis and design, andapplication interoperability

UML, MOF, XMI, Common Warehouse Model

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Part II

Java-Based Application ServersAlso See Session 5 Handout on:

“ The RMI Activation Framework”“The RMI Naming Service”

“JNDI”“Jini - The Universal Network?”“Jini Connection Technology”

“JTS - Demarcated Transaction Support”“Understanding Java Messaging and JMS”

and Sub-Topic 1 Presentation on:“Java Naming and Directory Interface (JNDI)”

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Sample Java Application Server Services

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Jini’s Service-Based Architecture

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Jini’s Relationship to Other Java Services

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JMS Session, Connection, and Message Facilities

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Part III

Windows Services

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Win32 Services

Win32 executable that satisfy several propertiesLifetime is controlled by the Service Control Mgr (SCM)

Service is registered with SCM, and understands and obeysSCM commands

Service has its own login session or shares one withanother service

Service runs as a user or local system and abides to applicablesecurity

Service implements a set of service-specific functions:Starting up, message handler, communication back to SCM

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Part IV

Conclusion

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Summary

OMG, Sun, and Microsoft DOC platforms all share the OMAarchitectureOMG’s OMA provides the most comprehensive and detailed setof specifications for CORBAfacilities, and CORBAservicesJavaSoft has focused mostly on OMA services as part of theJ2SE, J2EE, and J2ME architecturesMicrosoft provides platform specific support for services and anintegrated set of horizontal and vertical facilities bundled withthe OS

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Readings

ReadingsBuilding Application Servers: Part II, Chapters 4-5Handouts posted on the course web siteExplore the add-on services and facilities provided on top ofthe VisiBroker, Orbacus, RMI, RMI-IIOP, and DCOMEnvironmentsRead related white papers/documentation on the VisiBroker,Orbacus, RMI, RMI-IIOP, and DCOM platforms

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Project Frameworks

Project Frameworks Setup (ongoing)Apache Web Server (version 1.3.20, www.apache.org)Perl (version 5.x, www.perl.com), PHPMicrosoft IIS with COM+ and ASP (), ChiliSoftApache TomcatMacromedia JRunApache Cocoon 2/XSPVisibroker, OrbacusRMI-IIOP

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AssignmentAssignment:

Explore the textbooks’ references to Application Servertechnology (continued)#5a: Investigate distributed object computing platforms’development environments for the add-on technologiescovered in this session. Write a short report that documentsyour findings and recommendations with respect toselection criteria in support of development environmentsfor application server technologies covered in this session#5b: See homework #4 specification (due date is 10/15/01)

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Next Session:J2EE Component-Based

Computing Environments (Part I)

EJB Component ModelJ2EE Integrated ServicesSecurity in J2EE Application Servers