A transaction processing (TP) application is a program that performs an administrative function by accessing a shared database on behalf of an on-line user. A TP system is an integrated set of products that supports TP applications. These products include both hardware, such as processors, memories, disks and communications controllers, and software such as operating systems (Oss), database management systems (DBMSs), computer networks and TP monitors. Much of the integration of these products is provided by TP monitors which coordinate the flow of transaction request between terminals that issue requests and TP applications that can process them.Today, TP represents over 25 percent of the computer systems market and is one of the growing segments of the computer business. TP applications appear in most sectors of large-scale enterprises such as airline reservation, electronic banking, securities trading, inventory and production control, communications switching, videotex, sales management, military command and control and government services.

Transaction processing monitors

Approximation methods for networks of queues with priorities

Over the past years, stress has been put on global deadlock processing in distributed database management systems. This paper presents the main results of evaluation studies which were intended to provide clues for the choice of a concurrency control mechanism for the SCOT project. The relationship between deadlock management algorithm and concurrency level is exhibited. Their respective influence on system performance is studied in the light of simulations of several concurrency control techniques. A good algorithm for concurrency control is that which controls the concurrency level while solving, as a side effect, the deadlock question.

Why control of the concurrency level in distributed systems is more fundamental than deadlock management

The use of database systems for managerial decision making often incorporates information-retrieval capabilities with numeric report generation. Of great concern to the user of such a system is the response time associated with issuing a query to the database. This study presents a procedure for estimating response time for one of the most frequently encountered physical storage mechanisms, the indexed file. The model provides a fairly high degree of accuracy, but is simple enough so that the cost of applying the model is not exorbitant. The model incorporates the knowledge that the distribution of access key occurrences is known to follow Zipf's law. It first estimates the access time required to complete the query, which includes the time needed for all input and output transactions, and CPU time used in performing the search. The effects of multiple users on an individual's response time are then assessed using a simple regression estimation technique. The two-step procedure allows for the separation of access time from multiuser influences.

Database performance evaluation in an indexed file environment

An overview of techniques available to address capacity planning in the production data processing environment is presented. The production data processing system is briefly described and its capacity is quantified. The measurement tools, reports, and data required to implement a capacity planning program are discussed. Modeling and prediction are placed in perspective with the overall objectives of the capacity planning process. Personnel (managerial and technical) and organization considerations are also discussed.

Overview of the capacity planning process for production data processing

Various aids and tools are used in capacity planning. One such aid, an analytic model, is discussed in this paper. Both the decisions made in the development of an aid and the way the aid is used are examined. Characteristics of a good planning aid are emphasized with the analytic model serving as the example.

Modeling considerations for predicting performance of CICS/VS systems

Modeling is a useful method to aid a planner in designing the interconnection of a number of systems for distributed data processing. In the implementation in this paper, a computer-based model for sites using CICS/VS is discussed. The model permits the system definition to be adjusted, taking into account such aspects as the number of sites, their interconnections, and workloads, so that a satisfactory configuration can be obtained.

P. H. Seaman

Papers

Modeling considerations for predicting performance of CICS/VS systems

Modeling distributed processing across multiple CICS/VS sites