Application Servers G Session 1 - Main Theme Legacy Application Server Technology. Dr. Jean-Claude Franchitti

Transcription

1 Application Servers G Session 1 - Main Theme Legacy Application Server Technology Dr. Jean-Claude Franchitti New York University Computer Science Department Courant Institute of Mathematical Sciences 1 Agenda Application Servers Generics Course Logistics, Structure and Objectives Knowledge Required Application Servers Evolution Supporting Technology Expected Features Related XML Technology Introduction to Component Technologies Summary Class Project Overview Readings Assignment #1 2 1

2 Part I Introduction 3 Application Servers Generics Modern Application Server Properties Rich/portable software Middleware between pervasive devices and back-office systems Platform independent programming interface Support legacy applications integration (EAI/B2Bi) XML-enabled Web-services enabled 4 2

3 Course Logistics Course Web Site Login/Password: appserv/appserv (not currently protected) Review syllabus Textbooks Building J2EE Applications with IBM WebSphere Microsoft.Net Distributed Applications: Integrating XML Web Services and.net Remoting 5 Knowledge Required Programming Languages (g ) Operating Systems(g ) Programming for the WWW Ability to program in Java Some exposure to XML and associated technologies 6 3

4 Other Useful Knowledge Web server configuration and the HTTP protocol Scripting languages (e.g., JavaScript, Perl, TCL, etc.) Database theory (normalization rules) Web publishing Enterprise applications design See Session 1 Sub-Topic 1 on Sample Enterprise Application Design See Session 1 Sub-Topic 2 on Sample Project Development Methodology See Session 1 Sub-Topic 3 on Detailed Project Development Methodology 7 Application Servers Evolution Traditional client-server technology CGI frameworks Page-based extended HTML environments Distributed object computing platforms Java-Based Object Management Architectures (OMAs) Component-based computing environments Web Services platforms Next generation application servers (reflective, multimedia- and agent enabled, MDA-compliant, etc.) 8 4

5 Part II Supporting Technology 9 Underlying Facilities (Network) Communication Protocols e.g., TCP/IP, HTTP, RPC, GIOP/IIOP, RMI, XML, XML- RPC, SOAP/DIME/ROPE, UDDI/DISCO, WSDL Client-Server Technology Distributed Object Computing Component Models and Frameworks Secure Messaging Infrastructures 10 5

6 Old Client/Server Model Connection Customers (and partners) were required to have dedicated lines, leased lines, dialups, or some other access to your company. Network Protocol Customers had to use the same network protocols as the company they wanted to communicate with, TCP/IP, IPX/SPX, NetBUI, etc. Hardware Requirements Customers had to meet specific machine requirements: microprocessor speed; screen resolution; RAM; hard disk space; modem speed; etc. Customers were required to make a huge investment in hardware. Operating System Requirements The customer had to run a specific Operating System and version. Software Updates Application updates via floppy disks or CDs had to be infrequent. The 11 customer was required to perform the costly installation or update. Web Business Evolution First it was Online Publishing The World Wide Web - a Global Information Network Emerged (The Information Superhighway) The Web Browser Provided Platform-Independent Access to Information People Could View the Same Content Anywhere in the World There was Explosive Growth in the Number of Business Web sites Now it s Online Services and Web Applications. Businesses are Building Relationships with Web-based Customers Value-Based Services are Ensuring a Steady Flow of Web-based Traffic Overhead is Reduced with Automated Online Services A New Global Marketplace is Emerging - Web Applications/services are Available from Anywhere in the World 24x7 Web Application Updates Occur Instantly and Universally Doing Business is now Cheaper, Faster, and Easier 12 6

7 Basic Web Applications Documents Internet Connection DB Databases Client Browser Web Server CGI, SSJS, NSAPI, ISAPI, WAI, Etc. Enterprise Data 13 Robust Web Applications Presentation Tier Business Logic Tier Data Tier HTTP Documents Databases Web Browser Web Servers IIOP Enterprise C/S Applications Application Server(s) Rich Clients (Java C/C++, VB) Legacy Systems 14 7

8 Mission Critical Applications Requirements High Performance and Scalability Benchmarks demonstrate concurrent users, 12,000 TPM on a 4-CPU Sparc High Availability & Reliability Customers like E*Trade & ISN demand 24x7 reliability with software & hardware fault tolerance ebay on WebSphere 30 billion transactions per day Over 8,000 tps! Countrywide Insurance on WebSphere Over 20,000 tps! 15 Mission Critical Applications Requirements (continued) Rapid Development through Pre-built Application & System Services Proven that large-scale enterprise applications can be built in half the time with equivalent resources Enterprise Integration Need for high-performance integration to databases, legacy systems, client/server applications and ERP applications Open & Extensible Need for standards-based, cross-platform supporting Windows/UNIX, JAVA/C++, CORBA/IIOP, RMI/IIOP, and.net/com+ 16 8

9 Usability Scalability Concurrency Extensibility Security Manageability Application Servers Selection Criteria Fault tolerance, auto-deployment, communications, development environment, monitoring tools Reusability Support Skills 17 Application Server Categories Legacy technology Page-based extended HTML environments OMA-based Web Services platforms MDA-based Next generation used to list many unclassified products 18 9

10 Application Servers Examples CGI-Perl custom environments ColdFusion MX, PHP 4, ASP, JSP Websphere 5.0 WebLogic 8.1 JBoss Inprise, iplanet, Sybase EAServer 19 Application Packages (SAP, PeopleSoft, Baan) ERP, and B2Bi Suites Human Resources Sales Automation Financial/Accounting Retail/Point of Purchase Manufacturing/Inventory Supply Chain Management 20 10

11 Part III Expected Features 21 Sample Features High performance & scalability Create applications that deliver data quickly and scale to hundreds and thousands of concurrent users. Maximum availability (24x7) Create applications that are available 24 hours a day, 7 days a week, even when you are updating them! Client Independence Access applications using web browsers or rich Java/C++ clients. Rapid application development (RAD) Develop your applications quickly and easily with pre-built system and application services, application builder, extension builder, and a variety of third-party tools. Enterprise Application Integration Connect to backend databases, existing client/server applications, and your 22 existing legacy systems. 11

12 Value Proposition What Customers are Building with it... Customer Self-Service on-line credit card customer care & billing portfolio management benefits administration Business-to-Business Efficiencies package tracking claims processing supply chain management sales automation Revenue Expansion on-line retailing, on-line trading loyalty programs travel and entertainment 23 Development Methodology Develop, Deploy & Manage Business-Critical Applications Develop Application Builder Deploy Manage Develop & deploy business applications in Java/C++ Extension Builder Develop & deploy Extensions in Java/C++ for enterprise application integration Application Servers High Performance & Scalability High Availability Client-Independence Rapid Development of Business Applications Enterprise Integration Administrator Application Administration & Management Server & Cluster Management24 12

13 Internal Architecture Client HTML Scalable, Reliable Application Architecture Java C/C++ Visual Basic 13

14 Services (continued) Key System Services Multi-process, Multi-threaded Dynamic Load Balancing Application Partitioning Asynchronous Processing Event Logging & Tracking Kernel Services Directory Services Messaging Key Administration Services Application Management Server Management 27 Application Builder Rapid Development of Business Applications Wizards for Point-&-click Development Pre-built Application Services and Class Libraries (Java, C/C++) Reusable Application Components Distributed Deployment of Application Components Distributed Development Using Three-Tier Programming Model Wizards for Point-&-click Development 14

15 Application Builder Robust Application Development Tools Application Logic Designer HTML Designer Query Designer Project Manager Third-party Tool Support Project Manager 29 Server Administration Advanced cluster management Enterprise-wide views of all servers and processes Event monitoring & alerts Multi-view graphical performance monitoring ACL, User & Group Management Load balancing customization Application administration Application partitioning Integrated deployment Performance Monitor 30 15

16 Extension Builder Extending Application Servers Functionality Application Server Extensions Existing Applications and Systems Client/server applications Enterprise Systems Legacy Applications Third-party Web solutions Pre-built System & Application Services Business Logic OR Extension Builder (Create Custom Extensions) Use Pre-built Extensions IBM MQ Series BEA Tuxedo IBM CICS, IMS ERP Extensions Technical Architecture Open and Extensible Browsers Web Servers Open Client Library Web Connectors ISAPI, NSAPI, CGI OCL Protocol Manager (HTTP, KCP, IIOP) Application Server (Java, C/C++) Embedded (bundled) IONA ORB Data Access Engine Extensions Extensions TP Monitors Legacy Client/server Data Sources RDBMS Oracle Informix Sybase DB2 SQL Server OODBMS ODI ODBC & JDBC Rich Clients Java, C/C++,VB Platforms Sun Solaris HP-UX SGI Irix Windows 32 NT 16

17 Part IV Related XML Technology 33 XML-Based Architectures Presentation-Oriented Publishing Frameworks XML-Based Application Servers Message-Oriented Middleware Frameworks Web Services Frameworks Peer to Peer (P2P) Computing XML-Based e-services Protocols and Architectures 34 17

18 XML MOM and POP Frameworks An XML support framework must include: XML Parser (conformity checker) XML applications that use the output of the Parser to achieve unique objectives) 35 POP Applications Support Frameworks Objective is to serve XML HTML generation applications are provided Sample solutions XML::Parser module with Perl XML processing via Java servlets e.g., IBM Alphaworks XMLEnabler See session 2 s sub-topic on XML POP Application Server Framework Apache s Cocoon Active Server Pages (ASP) with MSXML (see Serving XML with ASP, and rocket) 36 18

19 XML POP Packaged Solutions Enterprise Information Portal (EIP) toolkits e.g., DataChannel s XML framework Structured content management and retrieval systems e.g., Vignette s StoryServer Gauss Interprise s VIP XML-Gateway Poet s Content Management Suite Chrystal Software s Astoria 37 MOM Applications Support Frameworks Many applications can be envisioned One objective is to support application integration via XML data interchange Sample solutions: XML::Parser module with Perl XML processing via Java applications 38 19

20 XML MOM Applications Component-based modeling e.g., XML Metadata Interchange (XMI) Enterprise Application Integration Business-to-Customer (B2C) Applications e.g., e-commerce Business-to-Business (B2B) Applications e.g., WebMethods Bluestone s XML-Server, excelon 2.0 XMLSolutions ExeterXML server 39 Java and the Apache XML Project See related article at: 1D8FB42-EC59-4F7B-8215-EDBD80F6A471%7D List of XML Sub-Projects: Xerces: XML parsers in Java, C++ (with Perl and COM bindings) Xang: Rapid development of dynamic server pages, in JavaScript Xalan: XSLT stylesheet processors, in Java and C++ SOAP: Simple Object Access Protocol FOP: XSL formatting objects, in Java Crimson: Java XML parser derived from the Sun Project X Parser Cocoon: XML-based Web publishing, in Java Batik: Java-based toolkit for Scalable Vector Graphics (SVG) AxKit: XML-based Web publishing, in mod_perl 40 20

21 XML and Java Standards XML is a family of technologies XSL, XML Schema, XML Query, XPath, XPointer, XLink, XML Base, DOM, CSS, XSL/XSLT, XHTML, XForms, XML Encryption, XML Key Management, XML Signature, RDF, MathML, SMIL, SVG, X3D, etc. Review the current state of the XML standards at Review the current state of Java Technology and XML (JAXP) standards at Review the Java binding to DOM 2.0 at Core /java-binding.zip DOM Level 3 still at the specification stage 41 XML and Java Standards (continued) Java XML Pack Java Architecture for XML Binding (JAXB) Java API for XML Messaging (JAXM) Java API for XML Processing (JAXP) Java API for XML Registries (JAXR) Java API for XML-based RPC (JAX-RPC) Java Web Services Developer Pack (WSDP 1.1) Java XML Pack JSP Standard Tag Library (JSTL) Ant Build Tool Java WSDP Registry Server 1.0_04 Web Application Deployment Tool Apache Tomcat Container 42 21

22 Java & XML Frameworks XML Parsers Xerces-J Crimson Oracle XML parser XML Server-Side POP Frameworks Cocoon XML P2P/B2Bi/EAI (MOM) Frameworks JXTA, WebMethods, etc. 43 Java and Web Services Java Web Services Developer Pack (WSDP 1.1) Java XML Pack JavaServer Pages Standard Tag Library (JSTL) Ant Build Tool Java WSDP Registry Server 1.0_04 Web Application Deployment Tool Apache Tomcat Container

23 Java-enabled XML Technologies XML provides a universal syntax for Java semantics (behavior) Portable, reusable data descriptions in XML Portable Java code that makes the data behave in various ways XML standard extension Basic plumbing that translates XML into Java parser, namespace support in the parser, simple API for XML (SAX), and document object model (DOM) XML data binding standard extension (JAXB) 45 Part V Introduction to Component Technologies 46 23

24 Object-Oriented Programming Method of implementation in which programs are organized as cooperative collections of objects Objects are instances of some class Classes are members of a class hierarchy Classes are united via inheritance relationships in which child classes can share members of parent classes and have similar structure and behavior Class Language type with structure and behavior Named or anonymous Contain member variables and methods Object Instance of a class with own state, behavior, and identity 47 OOP Infrastructure More on OOP Language Compiler and Tools Facilitate OOAD process OOP Conceptual Framework Object Model Abstraction, encapsulation, modularity, inheritance hierarchy, polymorphic typing OM notions can be applied to component programming e.g., modularity in OOP via componentization! OOP and Component Programming are Difficult to Separate e.g., abstraction, encapsulation, etc

25 Polymorphism Subtype polymorphism More on OOP (continued) Abstract base classes with inheritance and abstract methods (C#) abstract class A { void f(); } class B extends A { void f() { Console.WriteLine( B class );} }; Parametric polymorphism Uses template classes or functions (C++) Ad-hoc polymorphism Achieved via operator and function overloading (+ -> concatenate) 49 Components Cannot exist without a component infrastructure Compilers use different name calling conventions Must introduce a component infrastructure that hides the underlying complexity of different tools and systems used when creating and deploying components Neither an object nor a class nor a combination May include many classes Component exports interfaces rather than methods Interfaces do not always have 1-1 correspondance with a class Not a module (closed static unit that encapsulates embedded abstractions) Component can only contain binary units (no source code) 50 25

26 Components A component interface is the unit of component behavior in which some logically grouped methods are exposed to clients Component properties Contain compiled program files Package compiled programs in a file that has a format known to the component infrastructure (e.g., DLL, CAB, JAR, EXE) Language neutral EJB? -> use software bridge to use JavaBeans from VC++ e.g., ActiveX bridge (component infrastructure) Registers with Component infrastructure via a unique name CB development tools may use introspection to explore components at runtime 51 Component Infrastructures & Models Component Infrastructure Set of system services based on a component standard that ensure the properties of the component are immutable and enables rules of component composition and interaction Component Model Defines component interaction and composition standards Components Subsume Standards, Component Infrastructures, Tools, and OOAD Enterprise assurance Performance Concurrency (stateful/stateless components), caching of data or component, distributed transaction management (many components may modify databases) Reusability (plug and play) & scalability (resource mgmt) 52 26

27 Part VI Conclusion 53 Summary Key Application Server Objectives Enable Rapid Development of Business Applications Provide Industry Leading Performance & Scalability Provide High Availability & Reliability Enable Enterprise Application Integration Allow Client-Independence (HTML, Java, C++, VB) Provide Open & Extensible Architecture 54 27

28 Class Project Project Description The project focus is two-fold: Based on a framework-based enterprise application of your choice (e.g., multi-channel online community platforms ), you will implement common facilities and application-level services on top of various types of application server technologies to support the various aspects of your chosen application As you transition from one platform to another you will study and develop model-based migration and interoperability tools that leverage off of the cutting-edge concepts subsumed by modern Model Driven Architectures (MDAs) 55 Readings Readings Handouts posted on the course web site Project Frameworks Setup (ongoing) Apache Web Server ( Perl

29 Assignment Assignment: #1a: Investigate legacy application server development environments. Write a short report that documents your findings and recommendations with respect to selection criteria in support of legacy development environments for application server technology #1b: Come up with a framework-based business application and implement it on top of the core technology supplied as part of the homework #1 documentation 57 Next Session: Page-Based Application Servers (Part I) ColdFusion 6.1/MX Environment PHP 4 Environment XML-Based Application Servers 58 29