Thursday, August 8, 2019

A comparison of CORBA and Web Services Essay Example | Topics and Well Written Essays - 4000 words

A comparison of CORBA and Web Services - Essay Example Distributed Applications refer to the applications which can be distributed across different processors and computer systems.This concept helps in deploying an application across systems on a network which might be working a common project or an application. Distribution introduces a whole new set of semantics for ease of computing; some applications by their very nature are distributed across multiple computers because of one or more of the following reasons (Chaffee & martin, 1999):There are some applications which might need to access common data. Therefore, the data which these applications must access must necessarily be residing on multiple systems for administration and ownership reasons. There are several options available with distributed applications like an owner could permit the accessibility of the data-the data might be permitted to be accessed remotely but not stored on the local systems. If the data cannot be co-located, it must necessarily exist on multiple heterogen eous systems. Many applications in particular make the use of multiple processors in parallel computing to run an application and to solve a problem. Other applications may execute on multiple computers in order to take advantage of some unique feature of a particular system. Distributed applications most definitely take advantage of the scalability and heterogeneity of the distributed system (Chaffee & Martin, 1999). Some applications execute on multiple computers because users of the application communicate and interact with each other via the application. Each user executes a piece of the distributed application on his or her computer, and shared objects, typically execute on one or more servers. A typical architecture for this kind of application is illustrated below. Fig 1: Distributed Applications (Chaffee & Martin, 1999) It is necessary for the Distributed application developers to address several issues in a local program where in one operating system process all logic is executed. There are some differences between the objects that are co-located in the same process and the objects that can interact across processes or machine boundaries. The objects that are co-located can communicate faster than the ones that run on distributed applications. When in a group of objects which are co-located, one object fails, the whole of the object group fails. However, in the distributed applications, if one object among the whole bunch of objects running fails, it will not affect the other objects. Also the networks can be partitioned so as to separate the objects into different domains. Concurrent access in co-located objects is possible only through multiple threads. Concurrent access among the objects is possible in objects running in the distributed applications. Co-located objects are totally secure which i s evident through the fact that objects have access only among themselves and any other outer objects cannot access that group of objects. Objects in a distributed application environment are not secure since objects in such an environment are not protected against access from other processes. The communication speeds between the objects belonging to the same process are much higher when compared to the communication speeds between objects located on different machines. This statement implies that distributed applications which most probably might contain more than two objects having tight interactions should not be designed. If such applications are designed, the objects should be co-located to enhance the performance and the communication speeds. When two objects are co-located, they fail together; if the process in which they execute fails, both objects fail. The

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