1 a) What is decentralized processing? Also explain distributed data processing.


Decentralized Processing
Computer systems in different locations. Although data may be transmitted between the computers periodically, it implies limited daily communications. Contrast with distributed computing and centralized processing.


Distributed Data Processing (DDP)


Definition
The processing of information in separate locations equipped with independent computers. Even though the computers are connected by a network, the processing is geographically dispersed.


Explanation
There are numerous ways to describe Distributed Data Processing (DDP) structures and their associated characteristics of functional distribution components and user advantages and disadvantages. However, the bulk of the literature concerning DDP deals with its evolutionary impact and excludes consideration of the key generic characteristics of DDP and how these characteristics relate to user complexity, responsiveness, and user productivity.

Therefore, this study was undertaken to analyze generic Distributed Data Processing structures and their advantages and disadvantages. In addition, it described the homogeneous and heterogeneous characteristics of representative DDP environments. During this process, a range of expected DDP models were developed and test case assessments between these hypothesized DDP models and real environments were matched.

For this study a comprehensive examination of related readings, professional interviews, case studies, and DDP experiments conducted by the writer were integrated to provide an insight into DDP structures and the changing business environment caused by this new DDP technology.

The study's principal conclusion is that Distributed Data Processing may be defined in multiple forms (models) of structural configuration and user functional characteristics. Further, these multiple forms are not homogeneous, that is, a more powerful DDP form is not a natural or logical multiplier of a simpler form. The forms are heterogeneous and may be distinguished from each other by their unique user advantages and disadvantages.

Finally, the study concluded that DDP represents an important business opportunity, and is here to stay as a meaningful and effective data processing option. Further, DDP will introduce a new spectrum of user data processing function, but will also introduce unanticipated system complexity as a consequence for users. Moreover, the study determined that, in some cases, DDP was wrought with inefficiency and complications because it was used with abandon. Therefore, data processing executives and professionals should be cognizant to recognize the characteristics of DDP models and their respective options, and then, determine, very specifically, the appropriate environment and associated model that best suits their organization's objectives.

1b) How would shared memory be used to communicate data between two processes?


Inter-Process Communication (IPC) is a set of techniques for the exchange of data between two or more threads in one or more processes. Processes may be running on one computer or on two or more computers connected by a network. IPC techniques are divided into methods for message passing, synchronization, shared memory, and remote procedure calls (RPC). The method of IPC used may vary based on the bandwidth and latency of communication between the threads, and the type of data being communicated.

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