Orfali, R. and Ha'key, D.: Client ,/Server Programming with JAVA and CORBA, 2nd Edition, New York, John Wiley And Sons Inc., 1998, ISBN: 047124578X.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....way to derive these specification components from the corresponding program components, when using a specific tool (i.e. GRADE) Our aim is to correlate the execution of programs with simulation analysis of specifications. In the context of reusable software components, Corba, JavaBeans [28] etc. have been de veloped specifically for distributed environments. These models are based on object oriented features, their interface is fixed and communication is achieved through Remote Method Invocation. The reusable components of Ensemble are designed for the Message Passing model of ....

Orfali, R. and Ha'key, D.: Client ,/Server Programming with JAVA and CORBA, 2nd Edition, New York, John Wiley And Sons Inc., 1998, ISBN: 047124578X.

....JWORB performance is reasonable when compared with other ORBs even though we haven t invested yet much time into optimizing the IIOP communication channel. The ping value for various ORBs is the range of 3 5 msecs which is consistent with the timing values reported in the Orfali and Harkey book [13]. However, more study is needed to understand detailed differences between the slopes for various ORBs. One reason for the differences is related to the use of Java object serialization by RMI. In consequence, each structure transfer is associated with creating a separate object and RMI performs ....

Robert Orfali and Dan Harkey, Client/Server Programming with Java and CORBA, Wiley 1997.

....We measured binding, rebinding and remote call times on two 133 MHz Pentium machines under Windows NT 4.0 (see table 1) Table 1: RMI and VisiBroker Comparison RMI VisiBroker Java to Java First bind 70ms 24ms Rebind 18ms 70ms ( Remote redraw fillCircle 5.8 6.3ms 4.0 4. 4ms Ping [7] 5.5ms 3.6ms Our clients use VisiBroker s ORB (Object Request Broker) which allows communication with remote objects on servers (on second tier) using CORBA specification. The ORB class library, consisting of approximately 2Mb of code, is included with Netscape (Communicator version 4.0 or ....

R. Orfali, D. Harkey, Client/Server Programming With Java and Corba.

....the analysis and the development of the OAs The functional approach, where the accent is mainly on the functions and their properties rather than on objects an their relations, helped us answering positively to the above question. 1 for a complete reference please see [7] 8] 14] 12] [9] We would like not to debate on the OBJECTs vs FUNCTIONs approaches, but to use useful concepts of the functional approach in the analysis and development of distributed architectures: a functional shift for object oriented programming, merging, whenever useful, functional and object oriented ....

R.Orfali and D. Harkey. Client/Server programming with Java and CORBA. Addison-Wesley, second edition, 1998.

.... environment executable in both sequential, parallel and heterogeneously distributed platforms (Zeigler 1999) CORBA (Common Object Request Broker Architecture) is 1333 Zeigler, Kim, and Buckley an open standard promulgated by the Object Management Group (OMG) a consortium of over 700 companies (Orfali and Harkey 1997). CORBA is rapidly gaining acceptance due to a thriving middleware market consisting of businesses enthusiastically adopting the technology and vendors providing maturing products to support it. DEVS CORBA refers to conceptual realization of a runtime infrastructure on top of CORBA middleware to ....

Orfali, R. and D. Harkey, Client/Server Programming with Java and CORBA. 1997, New York, NY: Wiley Computer Publishing.

....led by the OMG pursues a multi language approachbuilt around the CORBA model. It has been recently observed that Java and CORBA technologies form a perfect match as two complementary enabling technologies for distributed system engineering. In suchahybrid approach, referred to as Object Web [1], CORBA is offering the base language independent model for distributed objects and Java offers a languagespecific implementation engine for the CORBA brokers and servers. Meanwhile, other total solution candidates for distributed objects components are emerging such as DCOM by Microsoft or WOM ....

1. Robert Orfali and Dan Harkey, Client/Server Programming with Java and CORBA , 2nd Edition, Wiley 1998.

....by the application developers this enables reusability and integrability of existing codes but often leaves developers of new simulations without enough guidance. In WebHLA, we fill this gap by using the emergent standards of Web based distributed computing, referred by some as the Object Web [2] that integrate Java, CORBA, W3C and DCOM models for distributed componentware. Traditional HPCC, dominated by data parallel MPP didn t make significant inroads into the DoD M S where the focus is on task parallel heterogeneous distributed computing. Recent trends towards commodity based HPCC ....

Robert Orfali and Dan Harkey, Client/Server Programming with Java and CORBA , 2nd Edition, Wiley 1998.

....module de: tum: automate: manager provided in the le Manager.idl. This le includes the Core.idl le where the Element interface (cf. Section 3.1) and a basic exception interface named BasicException are de ned. Almost all interfaces follow the corresponding standards of the OMG interfaces (c.f. [3]) 10 5.1 Transactions The Transaction context interface o ers the three standard transaction operations: The begin operation starts a new transaction, the commit operation tries to perform the changes made within the transaction, and the abort operation takes back all those changes. All three ....

Robert Orfali and Dan Harkey. Client/Server Programming with Java and CORBA. John Wiley & Sons, 2nd edition, 1998.

....environment aimed at supporting the design and programming of reliable distributed applications through an extensive library of generic objects. The shortcoming of these systems is the lack of flexibility and the complexity of learning and use. The common object request broker architecture (CORBA) [7] is a platform generally for developing clientserver distributed object computing model. However, fault tolerance was not a major concern in CORBA design. This paper is aimed to promote distributed object methodologies to bring flexibility and modularity into distributed replication systems. ....

Robert Orfali and Dan Harkey. Client/Server Programming with JAVA and CORBA. John Wiley and Sons, Inc, second edition, 1998.

....wrappers and the JavaBean Component Architecture The CORBA component architecture is defined by the Object Management Group (OMG) and has a direct mapping to Java Beans. A CORBA bean is a CORBA object that can be invoked via Internet Inter ORB Protocol (IIOP) from within a client JavaBean [5]. Creating a CORBA bean does not require a separate builder tool when using a Java Integrated Development Environment (IDE) since a CORBA component written to the same naming patterns has design time support from the Java IDE. getName( String setName(name: String) void getVersion( String ....

R.Orfali, D. Harkey, Client/Server Programming with JAVA and CORBA, John Wiley & Sons, Inc., 1998

....persistence of data. Today, this is typically done by a relational database. When integrating relational databases into an OTM 2 system, issues regarding mapping of persistent entities, scalability, and management of distributed data must be considered, while assuring performance and reliability [Orfali Harkey 98, Shussel 96] In large scale distributed systems, network communication and database access degrade performance significantly. Performance has traditionally been achieved by using caches, e.g. in the development of operating systems. Further, object caching is a commonly used technique in ....

....object management is crucial in large scale systems with a large number of server objects. Typically an OTM would: activate and deactivate components (distributed objects) coordinate distributed transactions, notify components of events, and automatically manage the state of components [Orfali Harkey 98] The OTM should thereby introduce scalability, load balancing, fault tolerance, security, and persistence into a CORBA environment. Both TP Monitor and ORB vendors currently move their products towards the OTM framework. One example of this is the cooperation between Transarc (TP Monitor vendor) ....

R. Orfali, D. Harkey. Client/Server Programming with JAVA and CORBA. 2 nd edition. Wiley, USA, 1998.

....O in S . Thus any method of O can invoke a method of O . This very likely happens when a remote reference is passed as a parameter in a request to S. In fact, we face a transitive application of the master slave pattern [3] Furthermore, this is also the underlying idea of n tier architectures [13]. Similarly, we can also achieve callbacks from a server to its client by passing a remote reference of the interface, which is to be the subject of a callback from the client to the server (see also Section 2.5) 2.5 Reactive programming The advantage of easy passing of remote references as ....

Orfali,R., Harkey,D.: Client/Server Programming with JAVA and CORBA, John Wiley, 1997

....to guarantee performance of the system. In this paper, we focus attention on the development of a CORBA Object Transaction Monitor (OTM) based system. CORBA OTM refers to an advanced middleware technology that has been adverted a major trend for next generation distributed transaction processing [11]. CORBA OTM consists of the standard object request broker (ORB) providing mechanisms for remote object invocation [9] and a set of object services for distributed systems and data management, including the CORBA Object Transaction Service (OTS) 10] We develop an object caching strategy that ....

R. Orfali, D. Harkey. Client/Server Programming with Java and Corba, 2nd edition. Wiley, 1998.

....is DCOM. In DCOM interface (types) have a unique identifier, but objects do not. To close this gap, DCOM introduces Monikers which allow to map DCOM objects to names. However, Monikers are insufficient for our purpose, as they are a crude way to establish connections between components (cf. [OH97]) Hence, we suggest to implement an own name service on top of DCOM or use standardized implementations, as, e.g. provided in CORBA. 13 To implement the example given in Figure 4 using DCOM each component is mapped into a DCOM object. Besides the standard DCOM interfaces IUnknown and ....

R. Orfali and D. Harkey. Client/Server Programming with JAVA and CORBA. John Wiley and Sons, 1997.

....that processes work orders as a group rather than individual items in an order. The changes to the software execution model for 7 The CPU time for ORB processing is from performance benchmarks on a particular platform, and is unlikely to generalize to other environments. See [GOKH97] and [ORFA97] for other measurement values. Figure 7. Customer Service Overhead Matrix Figure 8. Best case elapsed time. 14 this alternative are relatively minor the number of loop repetitions is reduced to 2 (one for orders ready to ship, the other for orders requiring back ordered items) and ....

R. Orfali and D. Harkey, Client/Server Programming with Java and CORBA, John Wiley and Sons, New York, NY, 1997.

.... infrastructures and middleware layers, hence a market target of fast time to availability operations stations; # Interoperability among systems makes it possible to consider a more efficient resource sharing among different operators of widely varying skills, resources and geography ( 17] [14]) This would enable 4 satellite servicing and sales to many customers from many different geographical areas, thus vastly extending the market potential; # Scripting languages such as Java may be used, at a low cost, to add SNMP capabilities to communicate with otherwise unmanaged equipment; ....

Robert Orfali and Dan Harkey. Client/Server Programming with Java and CORBA. John Wiley & Sons, Inc., 1997.

....proprietary components. RMI also provides a simple solution to distribute the processing of intensive tasks from the client to the server among different servers. But we found that RMI is much slower than using socket as shown in Table 1. The test results of Table 1 are based on Ping performance[14]. Since execution speed is a major factor in designing our system, we choose to develop our own collaborative system by using Socket. However, we must consider other methods to implement the collaboration features. One of these is a collaboration tool which will be released from Sun Microsystems. ....

Orfali, Robert, Client/Server programming with Java and CORBA, 1997 John Wiley & Sons Inc.

....that his choice has its (albeit minor) consequences on the way the various specifications in the book are defined and presented. At the time of writing this book, there are, broadly speaking, three alternatives one could choose from to control the distributed access of Java objects (see, e.g. [70] or [86] for further details) 4. Microsoft s DCOM (Distributed Component Object Model) used with Java (i.e. Visual J ) 5. Some form of an OMG CORBA implementation with a Java interface (ILU, Netscape s ONE or Caffeine, OrbixWeb, etc. or 6. Sun s (i.e. Javasoft s) own RMI (Remote Method ....

....for a smart application management, such as metadata information about objects, rich interface repositories, global access information, etc. These specification are the subject of a series of ongoing work within, for example, OMG (so called traders, interface repositories, etc. see, e.g. [70,86]) and it is very probable that appropriate Java APIs will also be published in the near future. It is not the goal of PREMO to compete with these. Instead, it should rely on the general concepts underlying these specifications. In line with the charter of PREMO, i.e. to provide a reference model ....

R. Orfali and D. Harkey. Client/Server Programming with JAVA and CORBA. Wiley Computer Publishing, 1997.

....to do this kind of work or implement an extension to Ontolingua enabling the translation of ontologies into Java interfaces. Ontolingua offers a flexible manipulation of ontologies that allows inclusion of entire ontologies or of only some references. A CORBA Interface Definition Language (IDL) [27] header file can be generated by Ontolingua. A CORBA IDL is a skeleton of ontologies and their components that should be complemented by implementation code written in Java [28] The resulting components are geographic objects. The model for implementing the geographic many roled objects is ....

Orfali, R. and Harkey, D., Client/Server Programming with Java and CORBA, Second Edition. New York: John Wiley & Sons, 1998.

....client side framework for credit card, debit card, and electronic transactions. It is a mixture of Base and Standard Extension APIs. 6.3 Java Object Model Java does not define a language independent object model, unlike CORBA and COM. It supports multiple interface inheritance, similar to CORBA [Orfali and Harkey 1997]. However, it supports single implementation inheritance, unlike CORBA and COM which do JVM Porting Interface 31 not support implementation inheritance. Java separates object interfaces from their implementations, similar to CORBA and COM. Java objects, like COM objects, may support multiple ....

....the beginning, and was designed for distributed applications. A combination of two or more middleware technologies is also a possibility. A good example here is a combined CORBA and Java middleware where Java provides the code foundation and CORBA provides the distributed object infrastructure [Orfali and Harkey 1997]. Here Java provides the language as well as the component architecture, JavaBeans, that CORBA lacks. CORBA, on the other hand, provides the communication protocol, IIOP, many wellspecified services, and a clean object model. Java objects can interact with other objects, written in other ....

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Orfali, R. and Harkey, D. 1997. Client/Server Programming with Java and CORBA, Wiley & Sons, Inc.

....and the connections between the subcomponents and with the supercomponent, e.g. aggregation or inheritance in UML Class Diagrams [23] or architecture description languages [5] Interface Documents describe the interfaces of components. Currently most interface descriptions (e.g. CORBA IDL [24]) only allow one to specify the syntax of component interfaces. Enhanced descriptions that also capture behavioral aspects use pre and post conditions, e.g. Ei el [20] or the Java Modeling Language [18] Protocol Documents describe the interaction between a set of components. Typical ....

R. Orfali and D. Harkey. Client/Server Programming with Java and CORBA. John Wiley & Sons, 1997.

....composition tools. Most dynamic description techniques rely on the message sets defined within signatures, and many programming languages offer static type checking based on purely syntactical properties of the considered program. Good examples for signature descriptions are CORBA IDL files [COR, OH98] and Java interfaces [Fla96] In the following, we demonstrate how interface signatures may be formalized based on the proposed formal system model. The presentation is structured in two parts: the first paragraph provides the translation of the example signature Counter into the corresponding ....

Robert Orfali and Dan Harkey. Client/Server Programming with Java and CORBA. John Wiley & Sons, 2nd edition, 1998.

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Robert Orfali and Dan Harkey. Client/Server Programming with JAVA and CORBA. John Wiley & Sons, Inc., 2nd edition, 1998.

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R.Orfali and Harkey D. (1998). Client/Server programming with Java and CORBA. Addison-Wesley, second edition.

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Robert Orfali and Dan Harkey, 1998, Client/Server Programming with Java and CORBA , 2nd Edition, Wiley.

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