M. Shapiro. Structure and encapsulation in distributed systems: the proxy principle. International Conference on Distributed Computing Systems. IEEE, 1986.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....which generates a response. Component based technology uses an object oriented approach where the client invokes server methods to achieve message passing. For distributed communication, component based technology prescribes a proxy agent to handle method invocations that cross process boundaries [14]. Since responses can take time, clients have a number of options in awaiting a response. Synchronous communication involves the client issuing a request to the server and then blocking, waiting for a server response. Upon receipt of the server response, the client resumes processing. ....

Shapiro, M., "Structure and Encapsulation in Distributed Systems: The Proxy Principle," In 6TH International Conference On Distributed Computing Systems, IEEE Computer Society Press, pp. 198204, May 1986

....a component based approach raises doubts about the need for a centralized dictionary. In a distributed component based approach, the HMI could directly access any Controller component. Instead of a single data server, each Controller component provides its own data services through a proxy server [12]. A component proxy server is an essentially free by product of component based technology that comes in support of location transparency. Figure 6 illustrates the distributed component based approach. COM axis group AxisGroup Figure 6. Distributed HMI Controller COM model A ....

Shapiro, M., "Structure and Encapsulation in Distributed Systems: The Proxy Principle," In 6TH International Conference On Distributed Computing Systems, IEEE Computer Society Press, pp. 198204, May 1986

....is no trust boundary within a domain which eases administration and allows a domain complete freedom in what code it runs. Because the domain contains no trusted code it is a sandbox that is completely closed. We create a new hole by introducing capabilities, called portals. Portals are proxies [55] for a service that runs in another domain. Portals look like ordinary objects and are located on a domains heap, but the invocation of a method synchronously transfers control to the service that runs in another domain. Parameters are copied from the client to the server domain. Portals and ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: The Proxy Principle. In ICDCS 1986.

....own protection policy independently from any other application or server and this policy specification is defined separately from the application implementation using views, thus enhancing modularity. In the following, we describe two implementations of this model, respectively relying on proxies [9] and on bytecode injection [1] 3 Proxy Based Implementation For the implementation of this protection model, we used the fact that Java object references are almost capabilities (Java is strongly typed) Indeed, since Java is a safe language, it does not allow object references to be forged. ....

....a Java object reference can be seen as a capability. However, they are all or nothing capabilities since it is not possible to restrict the set of methods that can be invoked using this reference. In order to implement our capabilities, we implemented a mechanism inspired from the notion of proxy [9], which allows access rights associated with a reference to be restricted. Our implementation relies on the management of filters that are inserted between the caller and the callee. For each view defined by an application, a filter class is generated (by a pre processor) and an instance of that ....

[Article contains additional citation context not shown here]

M. Shapiro, Structure and Encapsulation in Distributed Systems: The Proxy Principle, 6th International Conference on Distributed Computing Systems, 1986.

....services. For example, fragments of an object could be realized as data units, while relationships between fragments could be built with data unit links. The language implementor could chose between message passing and distributed shared memory to manipulate fragment instances [16] The proxies [21] necessary to communicate between different fragments provide a service very close to the FORWARD primitive mentioned above. However, perhaps the greatest benefit of the ARCADE data model would be the natural inclusion of object identification with data unit links. 5.3 Language Support with Data ....

Shapiro, M., "Structure and encapsulation in distributed systems: the Proxy Principle", Sixth Int'l Conf. on Dist. Computer Sys, May, 1986, pp 198-204.

....object references can be seen as capabilities. However, they are all or nothing capabilities since it is not possible to restrict the set of methods that can be invoked using such a reference. In order to implement our capabilities, we imple mented a mechanism inspired from the notion of Proxy [Shapiro86], which allows access rights associated with a reference to be restricted. Our implementation relies on the management of filters that are inserted between the caller and the callee. For each view defined by an application, a filter class is generated (by a pre processor) and an instance of that ....

M. Shapiro, "Structure and Encapsulation in Distributed Systems: The Proxy Principle", Proc. of the 6th International Conference on Distributed Computing Systems, pp. 198-204, 1986.

....(QoS) level [6] Under any circumstances, adaptability is desirable as it lengthens the lifetime of an entity, offers flexibility, and generally, saves effort, time, and resources. In this paper, we propose a new mechanism called the Mobile Proxy (MP) mechanism, based on the proxy principle [23], as a means of achieving adaptability in distributed applications integrated using the Common Object Request Broker Architecture (CORBA) technology [25] A proxy is defined as a service representative that resides at the client s site. It provides an interface to the service and takes care of ....

M. Shapiro, "Structure and Encapsulation in Distributed Systems: the Proxy Principle", in Proceedings of the 6th International Conference on Distributed Computing Systems, Cambridge, Massachusetts, USA, May 1986, pp. 198-204.

....remapping operations without OS intervention. They can be used for associating specific access semantics to address space regions, for example, delay upon read access (variable value has not yet been computed) signal upon write access , remote object invocation , access by proxies [Shapiro 1986] or simply access protocol . Remote object access can be implemented by local object invocation methods. Memory accesses are performed directly in the local case and algorithmically in the remote case. Distinction is by hardware. 3 Cost Measures We use optimal worst case models whenever ....

Shapiro, M. 1986. Structure and encapsulation in distributed systems: The proxy principle. In 6th International Conference on Distributed Computing Systems, Cambridge, MA.

....ffl Call on Reference Calling a user defined procedure upon access. This is to associate specific access semantics to address space regions, for example, delay upon read access (variable value has not yet been computed) signal upon write access, remote object invocation, access by proxy [20] or simply access protocol. 3.1 = alias 21 Combining the two methods allows an efficient realization of distributed memories since access to potentially remote objects is feasible by means of local object invocation. Memory accesses are performed directly in the local case and algorithmically ....

M. Shapiro. Structure and encapsulation in distributed systems: The proxy principle. In 6th International Conference on Distributed Computing Systems, Cambridge, MA, May 1986.

....[17] CORE uses a remote object model. In this model, an object is placed in the address space of a single object server. The object server exports the object s interfaces to remote clients, allowing them to invoke the object s methods. The interface implementation at the client is called a proxy [15]. A proxy marshals a method invocation into a message that is sent to the object server. An incoming invocation request is then unmarshaled at the server, after which the method is invoked at the object, as shown in Figure 1. The object is identified by a globally unique object identifier, ....

M. Shapiro. "Structure and Encapsulation in Distributed Systems: The Proxy Principle." In Proc. Sixth Int'l Conf. on Distributed Computing Systems, pp. 198--204, Cambridge, MA, May 1986. IEEE.

....trader s use is not reduced actually. In the meantime, our original work relies on the use of wellknown mechanisms of distributed object computing Figure 12: The TORBA Explorer. middleware: the proxy principle, the ORB structure, and the component approach. The proxy principle has been de ned in [23] as a structural concept to build distributed applications, acting on the behalf of a remote object. This principle extends the RPC (Remote Procedure Call) mechanism as de ned in [3] in order to use it in an object oriented context (i.e. Remote Method Invocation) At the communication level, a ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: The Proxy Principle. In Proceedings of the 6th International Conference on Distributed Computing Systems (ICDCS 86), pages 198-204, Cambridge, Mass., USA, May 1986. IEEE.

....complexity and to increase reliability of trader based applications. However, our original work relies on the use of wellknown mechanisms of Distributed Object Computing middleware: the proxy principle, the ORB structure, and the component approach. The proxy principle has been defined in [13] as a structural concept to build distributed applications, acting on the behalf of a remote object. At the communication level, a proxy (a.k.a. stub) serializes invocations to remote objects like in CORBA [11] DCOM [3] and Java RMI [14] environments. Such a proxy implementation fully hides the ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: The Proxy Principle. In Proceedings of the 6th International Conference on Distributed Computing Systems (ICDCS 86), pages 198-- 204, Cambridge, Mass., USA, May 1986. IEEE.

....before the final implementation. In this case the chosen distributed communication technology should allow a rapid prototyping. Usually, object distributed communication involves the definition of proxies which represent remote services in the client space and encapsulate the remote object [14]. This way, remote requests are locally answered by the proxy which is responsible for locating the remote object and for proceeding with invocation, sending arguments and receiving results. This paper presents a design pattern [6] for distributed object communication that uses the proxy ....

....CorbaSComm, given a distributed name returns a CORBA reference. SC User ptr CorbaSC AgendaManager: getUser(const String name) Distributed Name dn = static cast Data Interface Agenda Manager (sp ) getUser(name) return SC User: narrow(this getCorbaRef(dn) 10. Related Work In [14] the proxy principle is described : In order to use one service, potential clients must first acquire a proxy for this service; the proxy is the only visible interface of the service . The presented design applies and extends this principle by relaxing transparency and defining the logical layer. ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: The Proxy Principle. In The 6th International Conference on Distributed Computer Systems, pages 198--204, Cambridge, Mass., 1986. IEEE.

....how to reach this device. A BDC E FHGJI K0LMG GON P Q RMPSA RTGMI N RJUHL A BDC K0LMGJG NJPVQ RJPSA RTGMI NVRMUOL K0LMG G NJP Q RMPSA RTGJI N RJUHL A BDC C W X A BDC C W X a) b) E FHGMI E FTGJI A BDC C WJX A BDC C WJX The principle is not new. It can be compared to the Proxy pattern [29]. That is how we can obtain total transparency of location. The caller never needs to know, if a device is really local or if the call is redirected. All communication can be performed through the inbound and outbound queues of the messaging instance (see figure 4) Communication channel control, ....

M. Shapiro. "Structure and encapsulation in distributed systems: The proxy principle", In Proceedings of the 6th International Conference on Distributed Computing Systems, pages 198-204, Cambridge, Massachusetts, USA, May 1986. IEEE Computer Society Press, Washington, DC, USA.

....objects known as client side and server side proxies. The client side proxy and the corresponding serverside proxy communicate with each other to transmit requests and responses. Basically, the client side proxy supports the same interface as the remote object does. The key idea behind proxies [17] is that the client calls a method m of the client side proxy to achieve the effect of calling m of the remote object. Thus, the client side proxy can be considered a local representative of the corresponding remote object. Similarly, the key task of a server side proxy is to delegate and ....

Shapiro,M.: Structure and Encapsulation in Distributed Systems: The Proxy Principle, Proceedings of the 6-th intl.conference on distributed computer systems, pp. 198-204, Boston, 1986.

....each fragment possibly residing in a different address space. The fragments of a fragmented object communicate to maintain a consistent view of the fragmented object to clients. A fragmented object client interacts with the fragmented object by using the public interface of a local proxy fragment[37]. Clients are not aware of the distribution of a fragmented object, and different clients of a fragmented object may have different interfaces to the fragmented object. Language support for the fragmented object model is provided by the FOG language[8] an extension of C . A fragmented object ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: the Proxy Principle. In Proceedings of the 6th International Conference on Distributed Computing Systems, pages 198-- 204, Cambridge, Mass, USA, May 1986. IEEE.

....are implemented in different modules may at run time reside in different protection domains, and possibly on different machines. Lipto can support location independence merely through location transparent invocation between objects. It implements this mechanism using the technique of proxy objects [19 ]. The lack of implementation inheritance also makes it easier to provide language heterogeneity for module implementations, because the external knowledge about modules is restricted to its set of interfaces. Also, Lipto s architecture allows the reuse of a module without access to its source ....

M. Shapiro. Structure and encapsulation in distributed systems: The proxy principle. In Proceedings of the Sixth International Conference on Distributed Computing Systems, pages 198--204, May 1986. 11

....on DreamTeam had to use data sharing services provided by the DreamTeam environment. These services had to be called explicitly. The new object manager hides these services. The first version of the object manager (Lukosch and Unger, 1999) handled shared objects by replacing them with proxies (Shapiro, 1986), as proxies provide a powerful way to hide data sharing services. Although this approach already simplified the handling of shared groupware objects, the class hierarchy was quite complex and the developer had to handle and define several different classes. To simplify the handling even more, we ....

Shapiro, M. (1986), "Structure and Encapsulation in Distributed Systems", Proceedings of the 6th International Conference on Distributed Computer Systems, pp. 198--204.

....There are various implementations for each phase and the implementation of one phase is independent from the remaining phases. While the primary purpose of all structuring tools for distributed objects is the encapsulation of distribution and data (e.g. shared objects [1, 2, 10] and proxies [8]) our execution model was developed with two goals in mind: first, ease the addition of new execution strategies in the system and, second, allow execution strategies to be modified at runtime depending on the dynamic behavior of objects without changing the code of the operation or the object. ....

....class for vector but different execution strategies. As with the SOR application, it was easy to change the invocation strategy of the object by changing one of its attributes at instantiation time. 6 Related Work Shapiro described an early model for structuring distributed object invocation in [8]. In this model, applications are written using at least two kinds of objects: a server and one or more proxies. To invoke a remote object, an application must first obtain a proxy which is responsible for servicing requests sent by the local application or for forwarding them 11 FFT: Variant ....

M. Shapiro. Structure and encapsulation in distributed systems: the Proxy principle. In International Conference on Distributed Computing Systems, pages 198--204, Cambridge, MA, May 1986.

....by the concept of dual objects [11] As implied by the name, a dual object has two representations, namely a prototype and a likeness (Figure 1) Prototypes are typically managed by clerks and may be accessed remotely via of their likenesses. Therefore the likenesses serve at least as proxies [14] for their prototypes. Furthermore, likenesses may encapsulate state information, which has been extracted from the prototype s public state. That information may be accessed and even manipulated without the need for remote object access. Upon any remote operation on the private state of the ....

M. Shapiro "Structure and Encapsulation in Distributed Systems: the Proxy Principle", In Proceedings of the 6th International Conference on Distributed Computing Systems, Cambridge, Mass., USA, pp. 198--204, May, 1986.

....CSCW although very few have more than one of the features below. 2.3.1. The proxy principle Distributed system services and subsystems may be complex and implemented as a set of communicating server objects. This complexity should not be visible to such services and systems. The proxy principle [Shapiro, 1986] hides this complexity by grouping these server objects into distinct groups called proxies. A proxy represents a distributed object which is not decomposable by a client. All proxies are local to their clients and clients must direct all communication to the proxy in order to use the service. ....

....In figure 2.5 server 1 could be a single user service which is being managed for multiple users by the proxy service. This technique explicitly separates the mechanisms (available in certain objects) from the policies which drive them (contained in others) which is then hidden 3 Figure taken from [Shapiro, 1986] pp200. Chapter 2. Supporting the needs of CSCW applications 22 from the system clients through a proxy. This separation of concerns inside the proxy (between the proxy service and the services under the proxy) would allow alternative models of control over the objects or other proxies also ....

Shapiro, M. (1986): "Structure and encapsulation in distributed systems: The proxy principle." in 6th International Conference on Distributed Computer Systems, May, 1986, pp.198-204.

....application for multidomain network management and shows how the adoption of Yasmin simplified the design of the application and allowed multiple network management protocols to be supported in a seamless way. 4.1. Liaison: a Yasmin Based software application Liaison [9] is a proxy application [22] [13] which allows users to manage network resources through the Web using CMIP [5] and SNMP [23] the two dominant protocols for network management. Issues encountered during the design and development of Liaison are mostly related to: the great difference between CMIP and SNMP, other than ....

M. Shapiro, Structure and Encapsulation in Distributed Systems: the Proxy Principle, 6th Int. Conference on Distributed Computing Systems, Boston, Mass., May 1986.

....errors during extensions. Therefore, our approach is to limit the use of the security manager to providing generic protection of system resources and not have it directly deal with the protection of application level objects. Another approach for establishing controlled access is to use proxy[23] objects. When an agent first makes a request to access a resource, the server consults the security policy and constructs a resource proxy, which is an object with a safe interface to the resource. If the agent is not trusted, certain operations on the resource may be disabled. A separate proxy ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: The Proxy Principle. In Proceedings of the 6th International Conference on Distributed Computing Systems, pages 198--204. IEEE, 1986.

....objects can issue and receive remote method calls with the object issuing the call referred to as client and the object receiving the call referred to as server. To bridge the conceptual gap between local and remote method calls, objects known as client sides proxies and server side proxies [8] are usually used. The key idea behind proxies is that the client calls a method m of the client side proxy to achieve the effect of calling the method m of the remote server; similarly, the server side proxy is used to transform an incoming request into a local call form and to transform the ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: The Proxy Principle. In Proceedings of the 6th International Conference on Distributed Computer Systems, pages 198--205, Washington, 1986. IEEE Press.

....CORBA compliant [7] which means that CORBA objects can be hosted on and accessed from an AspectIX implementation, and that AspectIX objects can be accessed from every other CORBA platform, but often with loosing the QoS support. 3. 1 Object Model Shapiro introduced the so called proxy principle [11], which conceptually considers a local access point to a remote service (a proxy) to be part of that service. In SOS [12] and Globe [16] this concept has been implemented using objects as basic building blocks of applications. A distributed object is partitioned into multiple distributed parts. A ....

....These problems have been solved and their solution is going to be integrated in our implementation. 4. Related Work The SOS operating system was built for the context of multimedia applications in a local network [12] It implements Shapiro s proxy principle in form of fragmented objects (FOs) [11]. SOS adopts its own protocols and has a different concept for realizing intra object communication. All communication is either modelled by so called channels or by other predefined fragmented objects. The AspectIX approach of communication end points allows more flexibility (e.g. also legacy ....

M. Shapiro: "Structure and encapsulation in distributed systems: the proxy principle." In Proc. of the 6th Int. Conf. on Distr. Comp. Sys. -- ICDCS (Cambridge, MA, May 19-23, 1986), IEEE Comp. Soc.,Wash., DC, 1986. pp 198--205.

....reflects the public interface of a dual class and consists of public and protected members only, whereas the prototype consists of all members. Furthermore, the likeness holds a (remote) reference to its prototype. Thus a likeness is both an object that can be manipulated locally as well as a proxy[28] for a remote prototype. Prototypes are implemented as passive C objects and are kept within domains that are controlled by object dispatchers. We call these object dispatchers clerks, since they are responsible for all object book keeping in a domain. When a dual object is created, an ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: the Proxy Principle. In Proceedings of the 6th International Conference on Distributed Computing Systems, pages 198--204, Cambridge, MA, 1986.

....concerned memory objects accessible via read and This work is supported in part by the Engineering and Physical Sciences Research Council grant 92600699 and DARPA contract DABT63 95 C 0125. write operations (DSM) 1] or fragmented objects offering relatively simple operational interfaces[2, 3]. Since then, object based research has moved toward more general representations of shared abstractions, including the support of arbitrary type hierarchies in object access[4] Simultaneously, researchers have investigated the efficient implementation of DSM, including the development of ....

M. Shapiro, "Structure and encapsulation in distributed systems: The proxy principle," in Proc. 6th IEEE ICDCS, Boston, Mass., pp. 198--204, IEEE, May 1986.

....and the underlying run time system to maintain consistency across distributed object components. Early research on distributed shared objects concerned memory objects accessible via read and write operations (DSM) 26] or fragmented objects offering relatively simple operational interfaces[11, 33]. Since then, object based research has moved toward more general representations of shared abstractions, including the support of arbitrary type hierarchies in object access[17, 34] Furthermore, many researchers have investigated the efficient implementation of DSM, including the development of ....

M. Shapiro. Structure and encapsulation in distributed systems: The proxy principle. In Sixth International Conference on Distributed Computing Systems, Boston, Mass., pages 198--204. IEEE, May 1986.

.... and system level functionality has also been explored in several recent object based efforts, including the Choices[7] Spring[24] Chaos[22] and Apertos[56] operating systems, and it has been investigated in efforts that address object fragmentation [12, 25] and fragmented network objects[48]. Program or operating system configuration may be performed with diverse methods and at different times, including at compile , link , boot time[10, 17, 7] Runtime configuration methods include the dynamic re linking of OS kernels, server process creation and deletion[40] the re direction of ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: The Proxy Principle. In Sixth International Conference on Distributed Computing Systems, Boston, Mass., pages 198--204. IEEE, May 1986.

....nodes. Since the unit of naming and caching is the cluster, we have to provide a mechanism for dynamic binding of inter cluster references. cluster1 cluster2 proxy out cluster object Figure 2. Binding of inter cluster references Our implementation relies on intermediate objects called proxies [Shapiro86] which are transparently inserted between the referenced cluster and the cluster which contains the reference (Figure 2) A proxy contains a Java reference that points to the referenced cluster object if it is already there and null if not. It also contains a unique name associated with the ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: The Proxy Principle, Proc. of the 6th International Conference on Distributed Computing Systems, pp. 198-204, 1986.

....it 7 , and indicates the request. CORBA offers two common techniques to achieve this: a stub and a dynamic invocation interface (DII) to the request broker (ORB) cf. Figure 13) The first allows for static type checking of remote references and invocations. A stub also often called a proxy [47] is a 7 A set of objects can share a single process to save resources (cf. Section 8) local representative of a remote object and is created in the client s process when the client assigns the identifier of a remote object to a reference variable. In the case of dynamic invocation ....

....ad hoc solution for this problem the entry of a newly bound object in the index could be extended by the identifier of the alliance in order to be able to update the address stored in the alliance when the object is moved. Alternatively a common proxy technique from distributed systems can be used [47]. Future research should pay further attention to mobile objects because they seem to become a very important feature for distributed applications. Access to the object index must be synchronized by transactions since more than one object or alliance may use it concurrently. Note that the object ....

M. Shapiro. Structure and encapsulation in distributed systems: The proxy principle. In 6th Intl. Conf. on Distributed Computing Systems, pages 198--205, Boston, Massachussetts, 1986.

....The most popular paradigm for distributed computing so far, the client server model, turned out to be insufficient to respond to the challenges incurred by rapidly increasing size and complexity of global computing and information resources. One extension to this model was the proxy mechanism[5], allowing the server to be locally represented at the client s side. This approach, however, has not solved many substantial problems which arose with the growth of the global computer network infrastructure and mobility of users. We see delegation of function as an important response to these ....

....that make service invocation possible only when the server is equipped with a corresponding skeleton routine. It makes client server relation very static that improves performance. And last, but not least, the client and server of a RPC call are totally separate entities. The proxy paradigm[5] was proposed as an extension to RPC, adding a server s representative at the client s address space. It may, however, be inefficient in an environment with a vast number of rapidly emerging services and resources. Detailed analysis of RPC and mobile agents leads to the conclusion that nearly ....

M. SHAPIRO, Structure and Encapsulation in Distributed Systems: the Proxy Principle, Proceedings of the 6th IEEE ICDCS, Boston, May 1986.

....the prototype is a mobile object. At any given time, each dual object has only one prototype, but it may have more than one likeness. The prototype logically has a private state and a public state. A likeness is built by extracting the public state and representing the extract as a proxy object [16], and exporting the proxy into the context from which allocation of the dual object was requested. In addition to the extract (i.e. the proxy instance) the likeness carries a systemwide unique identifier as the reference to the site (i.e. the server) storing the prototype. This identifier is ....

M. Shapiro. Structure and Encapsulation in Distributed Systems: the Proxy Principle. In Proceedings of the 6th International Conference on Distributed Computing Systems, pages 198--204, Cambridge, MA, 1986.

.... toward increased scalability and portability of parallel programs is the provision of the DSA library for the efficient implementation of objects termed Distributed Shared Abstractions (DSA) Scalability on SMP machines is achieved by implementation of such objects as sets of object fragments[41, 45] linked by a user defined communication structure, which we term a topology. The resulting parallel program s portability is improved by encapsulation of its shared abstractions as objects with operational interfaces that may remain invariant across objects different implementations for specific ....

....Services are executed only in response to top send operation. This simplification resulted in performance increases for the top send and top receive calls described in more detail in Section 4. Finally, to an end user, the object fragment shown in Figure 8 appears much like a proxie [45], since it locally emulates the object s complete functionality by exporting all of its operations. Namely, end users only know that the object s fragments F0 to F4 reside on processors P0 and P1 and that this tour object offers the operations read tour and new tour and contains the ....

M. Shapiro. Structure and encapsulation in distributed systems: The proxy principle. In Sixth International Conference on Distributed Computing Systems, pages 198--204, May 1986.

....in the client side of the server object. Its purpose is to ensure the creation of the requests and their routing towards the server, then to turn over the result to the client. In order to remain transparent, a proxy class adapts the style of local call to the mechanism of remote invocation [SHA 86] Separation of Concerns. The remote invocation mechanism is completely independent of the semantics of the IDL interface (e.g. Account) That is, remote invocation refers to the control of the application and not to the application functionality; it deals with meta level programming. The ....

SHAPIRO M. --- Structure and Encapsulation in Distributed Systems : The Proxy Principle. In Proceedings of the 6th International Conference on Distributed Computer Systems, p.198-204, Cambridge, MA, May 1986.

....each dual object has two representations, namely a prototype and a likeness (Fig. 1) A prototype represents the internal view of an object, whereas the likeness represents its outer appearance. Furthermore, the prototype representation is location dependent, whereas likenesses are proxy objects[16] which generally provide location independent prototype access. Dependent on the representation actually used, operations are performed either by local object invocations (Loi) or by remote object invocations (Roi) Since the prototype representation is statically known to reside within the same ....

M. Shapiro, "Structure and Encapsulation in Distributed Systems: the Proxy Principle," in Proc. 6th Intl. Conf. on Distributed Computing Systems, (Cambridge, Mass. (USA)), pp. 198--204, IEEE, May 1986.

....support metaobjects make distributed object interactions to be the same as local object interactions. 4.3. 1 Proxy objects A proxy object is an object (similar to a client stub) that is used to provide network transparency and hide argument passing details in a distributed processing environment [Sha86] A proxy is a piece of code that represents a server object on a client side, i.e. it runs on the same address space as the client. To access the server, the client simply performs a local invocation on the server s proxy. The proxy performs the actual remote invocation (cross address space ....

M. Shapiro. "Structure and encapsulation in distributed systems: the proxy principle". In Proceedings, 6th Int'l Conf. on Distributed Computing Systems, May 1986.

....not by copy. The run time system routes a client request via a proxy object to a target object that may reside in a remote address space. A proxy object is an object (similar to a client stub) that represents a server object on a client side, i.e. it runs on the same address space as the client [32]. A typical application may involve interactions with a variety of local and remote objects, but the proxy objects make distributed object interactions the same as local object interactions. To access a server object, the client simply performs a local invocation on the server s proxy. The proxy ....

M. Shapiro, "Structure and Encapsulation in Distributed Systems: The Proxy Principle," Proc. Sixth Int'l Conf. Distributed Computing Systems, May 1986.

No context found.

M. Shapiro. Structure and encapsulation in distributed systems: the proxy principle. International Conference on Distributed Computing Systems. IEEE, 1986.

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M. Shapiro. Structure and encapsulation in distributed systems: the proxy principle. International Conference on Distributed Computing Systems. IEEE, Catalog number 86CH22293-9, May 1986.

No context found.

M. Shapiro. Structure and encapsulation in distributed systems: the proxy principle. International Conference on Distributed Computing Systems. IEEE, 1986.

No context found.

M. Shapiro. Structure and encapsulation in distributed systems: the proxy principle. International Conference on Distributed Computing Systems. IEEE, Catalog number 86CH22293-9, May 1986.

No context found.

M. Shapiro. Structure and encapsulation in distributed systems: the proxy principle. In Proc. of the 6th Intl. Conf. on Dist. Computing Systems, pages 198--204, Boston, May 1986.

No context found.

M. Shapiro, "Structure and Encapsulation in Distributed Systems: The Proxy Principle," Proc. Sixth Int'l Conf. Distributed Systems, pp. 198-204, May 1986.

No context found.

M. Shapiro. Structure and encapsulation in distributed systems: the proxy principle. In Proc. of the 6th Intl. Conf. on Dist. Systems, pages 198--204, Boston, May 1986.

No context found.

M. Shapiro. Structure and Encapsulation in Distributed Systems: the Proxy Principle. In Proceedings of the 6th International Conference on Distributed Computing Systems, Cambridge, Mass. (USA), pages 198-204. IEEE, May 1986.

No context found.

M.Shapiro, "Structure and Encapsulation in Distributed Systems: The Proxy Principle," in 6th International Conference on Distributed Computing Systems, IEEE 6th International Conference on Distributed Computing Systems , pp. 198--204, IEEE Computer Society Press, May 1986.

No context found.

M. Shapiro, "Structure and encapsulation in distributed systems: the Proxy Principle", Proceedings of the 6th International Conference on Distribu- ted Computing Systems, pp. 198 204, Cambridge, Mass. (USA), 1986

No context found.

M. Shapiro. Structure and encapsulation in distributed systems: The proxy principle. In Proceedings of the Sixth International Conference on Distributed Computing Systems, pages 198 204, Boston, Mass., May 1986.

No context found.

M. Shapiro, \Structure and Encapsulation in Distributed Systems: the Proxy Principle," in International Conference on Distributed Computing Systems (ICDCS'86), (Cambridge, MA), May 19-23 1986.

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