17 research outputs found
Pricing of Information Services Using Real-Time Databases: A Framework for Integrating User Preferences and Real-Time Workload (Best Paper Runner Up)
Many revolutionary information products are being offered or envisioned in electronic commerce setting. Since an economic paradigm and mass customization are implicit in electronic commerce, these products must be produced and delivered at appropriate prices with user desired service characteristics such as response time, correctness, and completeness. In this research, we investigate the information services pricing with response time (or delay) as the only service characteristic since response time can implicitly characterize other quality attributes such as correctness. In order to recognize customers’ preferences, real-time databases, where transaction processing is time-cognizant, are central to information providers and can be thought of as “manufacturers” of customized products. We propose to capture user preferences by a priority pricing mechanism based on economic theory. This pricing is concerned with database access and is independent of content pricing. Our approach has a natural overload1 management and admission control2 techniques that can potentially increase collective benefits. Our model is evaluated using simulation and is shown to outperform a system without access pricing mechanism with respect to both system wide benefits and RTDB performance
SOA-RTDBS: A service oriented architecture (SOA) supporting real time database systems
With the increase of complexity in Real-time Database Systems (RTDBS), the amount of data that needs to be managed has also increased. Adoption of a RTDBS as a tightly integrated part of the SOA development process can give significant benefits with respect to data management. However, the variability of data management requirements in different systems, and its heterogeneity may require a distinct database configuration. We addressed the challenges that face RTDB managers who intend to adopt RTDBS in SOA market; we also introduce a service oriented approach to RTDBS analytics and describe how this is used to measure and to monitor the security system. A SOA approach for generating RTDBS configurations suitable for resource-constrained real-time systems using Service Oriented Architecture tools to assist developers with design and analysis of services of developed or new systems was also explored
A New Approach to Manage QoS in Distributed Multimedia Systems
Dealing with network congestion is a criterion used to enhance quality of
service (QoS) in distributed multimedia systems. The existing solutions for the
problem of network congestion ignore scalability considerations because they
maintain a separate classification for each video stream. In this paper, we
propose a new method allowing to control QoS provided to clients according to
the network congestion, by discarding some frames when needed. The technique
proposed, called (m,k)-frame, is scalable with little degradation in
application performances. (m,k)-frame method is issued from the notion of
(m,k)-firm realtime constraints which means that among k invocations of a task,
m invocations must meet their deadline. Our simulation studies show the
usefulness of (m,k)-frame method to adapt the QoS to the real conditions in a
multimedia application, according to the current system load. Notably, the
system must adjust the QoS provided to active clients1 when their number
varies, i.e. dynamic arrival of clients.Comment: 10 pages, International Journal of Computer Science and Information
Security (IJCSIS
Research issues in real-time database systems
Cataloged from PDF version of article.Today's real-time systems are characterized by managing large volumes of data.
Efficient database management algorithms for accessing and manipulating data are
required to satisfy timing constraints of supported applications. Real-time database
systems involve a new research area investigating possible ways of applying database
systems technology to real-time systems. Management of real-time information through
a database system requires the integration of concepts from both real-time systems and
database systems. Some new criteria need to be developed to involve timing constraints
of real-time applications in many database systems design issues, such as
transaction/query processing, data buffering, CPU, and IO scheduling. In this paper, a
basic understanding of the issues in real-time database systems is provided and the
research efforts in this area are introduced. Different approaches to various problems of
real-time database systems are briefly described, and possible future research directions
are discussed
Research issues in real-time database systems. Survey paper
Today's real-time systems are characterized by managing large volumes of data. Efficient database management algorithms for accessing and manipulating data are required to satisfy timing constraints of supported applications. Real-time database systems involve a new research area investigating possible ways of applying database systems technology to real-time systems. Management of real-time information through a database system requires the integration of concepts from both real-time systems and database systems. Some new criteria need to be developed to involve timing constraints of real-time applications in many database systems design issues, such as transaction/query processing, data buffering, CPU, and IO scheduling. In this paper, a basic understanding of the issues in real-time database systems is provided and the research efforts in this area are introduced. Different approaches to various problems of real-time database systems are briefly described, and possible future research directions are discussed. © 1995
An Analysis of Transaction Management in Distributed Real Time Databases: An Overview
A real time distributed computing has heterogeneously networked computers to solve a single problem. So coordination of activities among computers is a complex task and deadlines make more complex. The performance of the system depends on many factors such as traffic workloads data base system architecture, underlying processor, disk speeds, concurrency control, transaction management etc.[1,2,3,4,5,6]. A simulation study have to be performed to analyze the performance under different transaction scheduling, different workloads, arrival rate priority policies, altering slack factors and preemptive policies. The performance of the distributed system under various conditions is to be monitored and parameters such as arrival rate, transaction size, transaction distribution policies, and execution time are to be analyzed
Multiclass Query Scheduling in Real-Time Database Systems
In recent years, a demand for real-time systems that can manipulate large amounts of shared data has led to the emer-gence of real-time database systems (RTDBS) as a research area. This paper focuses on the problem of scheduling queries in RTDBSs. We introduce and evaluate a new algorithm called Priority Adaptation Query Resource Scheduling (PAQRS) for handling both single class and multiclass query workloads. The performance objective of the algorithm is to minimize the number of missed deadlines, while at the same time ensuring that any deadline misses are scattered across the different classes according to an administratively-defined miss distribution. This objective is achieved by dynamically adapting the system’s admission, mem-ory allocation, and priority assignment policies according to its current resource configuration and workload characteristics. A series of experiments confirms that PAQRS is very effective for real-time query scheduling
Real-time transaction scheduling in database systems
A database system supporting a real-time application, which can be called "a real-time database system (RTDBS)", has to provide real-time information to the executing transactions. Each RTDB transaction is associated with a timing constraint, usually in the form of a deadline. Efficient resource scheduling algorithms and concurrency control protocols are required to schedule the transactions so as to satisfy both timing constraints and data consistency requirements. In this paper,† † An earlier version of this paper was published in the Proceedings of ACM Computer Science Conference '92. we concentrate on the concurrency control problem in RTDBSs. Our work has two basic goals: real-time performance evaluation of existing concurrency control approaches in RTDBSs, and proposing new concurrency control protocols with improved performance. One of the new protocols is locking-based, and it prevents the priority inversion problem‡ by scheduling the data lock requests based on prioritizing data items. The second new protocol extends the basic timestamp-ordering method by involving real-time priorities of transactions in the timestamp assignment procedure. Performance of the protocols is evaluated through simulations by using a detailed model of a single-site RTDBS. The relative performance of the protocols is examined as a function of transaction load, data contention (which is determined by a number of system parameters) and resource contention. The protocols are also tested under various real-time transaction processing environments. The performance of the proposed protocols appears to be good, especially under conditions of high transaction load and high data contention. © 1994