A classification of transaction processing systems

The problems in building a transaction processing system are discussed, and it is shown that the difficulties are a function of specific attributes of the underlying database system. A model of a transaction processing system is presented, and five system dimensions important in classifying transaction processing systems-the process, machine, heterogeneity, data, and site components-are introduced. The specific problems posed by various combinations of system characteristics are analyzed. The evolution of transaction processing systems are described in terms of the framework     

A strawman reference model in transaction processing for an object-oriented database

This position paper provides a strawman reference model which can be used to compare and reason about transaction management in an Object-Oriented Data Base system (OODB). The model is described as consisting of a collection of characteristics that can be used for comparing existing and future features in transaction management of an OODB. Some of the features in this collection are really alternatives to one another. The purpose of inclusion of these alternatives is to help the evaluation process when developing standards.     

移动数据库事务处理模型的研究

在移动数据库系统中,事务的移动性、频繁断接性以及长事务等特性使得传统的事务处理模式不再适用。提出一种扩展的乐观两阶段提交事务处理模型（O2PC-MT）,该模型吸收了O2PC-MT模型的设计思想,解决了由短暂的通信失效造成不必要的事务中止以及移动事务协调器故障导致的阻塞等问题。实验结果表明,与O2PC-MT事务处理模型相比,EO2PC-MT提高了系统的事务吞吐率以及改善了系统的总体性能。     

Using optimistic atomic broadcast in transaction processing systems

Atomic broadcast primitives are often proposed as a mechanism to allow fault-tolerant cooperation between sites in a distributed system. Unfortunately, the delay incurred before a message can be delivered makes it difficult to implement high performance, scalable applications on top of atomic broadcast primitives. Recently, a new approach has been proposed for atomic broadcast which, based on optimistic assumptions about the communication system, reduces the average delay for message delivery to the application. We develop this idea further and show how applications can take even more advantage of the optimistic assumption by overlapping the coordination phase of the atomic broadcast algorithm with the processing of delivered messages. In particular, we present a replicated database architecture that employs the new atomic broadcast primitive in such a way that communication and transaction processing are fully overlapped, providing high performance without relaxing transaction correctness.     

A transaction model and multiversion concurrency control for mobile database systems

Transaction management on Mobile Database Systems (MDS) has to cope with a number of constraints such as limited bandwidth, low processing power, unreliable communication, and mobility etc. As a result of these constraints, traditional concurrency control mechanisms are unable to manage transactional activities to maintain availability. Innovative transaction execution schemes and concurrency control mechanisms are therefore required to exploit the full potential of MDS. In this paper, we report our investigation on a multi-versions transaction processing approach and a deadlock-free concurrency control mechanism based on multiversion two-phase locking scheme integrated with a timestamp approach. We study the behavior of the proposed model with a simulation study in a MDS environment. We have compared our schemes using a reference model to argue that such a performance comparison helps to show the superiority of our model over others. Experimental results demonstrate that our model provide significantly higher throughput by improving degree of concurrency, by reducing transaction wait time, and by minimizing restarts and aborts.     

Building blocks for adaptable factory systems

Markets are becoming increasingly dynamical and unpredictable. Trends such as the shortening of the product life cycle, individualization of customer requirements and globalization, which includes an adaptation to international markets and standards, can be observed. In result, demands for adaptable factory systems are increasingly addressed towards an industrial engineering. The department of Factory Planning and Factory Management of Chemnitz University of Technology has proven its competences on this subject by developing approaches like Component-based Planning, PLUG+PRODUCE, High Performance Ramp-up or Competence-Cell-based Production Networks. These competences are now used in the project “Building Blocks for Adaptable Factory Systems”. In this project, partial factory systems are basically researched and transferred to an industrial practice. The objective is to achieve an adaptability, which meets the particular requirements of the planning situation. This is tried to be met by the elaboration of change-drivers like universality, mobility, scalability, modularity and compatibility. Therefore, the drivers' working principles have to be understood and made accessible. Concepts, procedures and methods for the design of future adaptable factory systems have to be developed. The central component of the set of building blocks is a manufacturing complex connected to the logistics system of an Experimental and Digital Factory by custom-built interfaces. The adaptability of the system is supported among others by tools for the digital factory, innovative identification and positioning systems, concepts for the supply of material and the self-controlling of logistical objects, as well as man–machine-interfaces. The paper will give an overview about the approach of Building Blocks for Adaptable Factory Systems. The relevant terms are defined and the underlying concepts are presented. Concepts for central controlling as well as distributed controlling with an RFID are introduced. First building blocks will be introduced. Deployed tools and equipment are discussed. Approaches for an effective energy management are explained.     

Simulation studies on concurrency control in parallel transaction processing systems

Parallel transaction processing (TP) systems have great potential to serve the ever-increasing demands for high transaction processing rate. This potential, however, may not be reached due to the concurrency control (CC) requirements. In this paper a simulation system for shared-nothing parallel TP systems was presented, which aims at, but is not restricted to, the studies of the CC methods. A distributed locking-based CC method called LW DC_k (local wait-depth control) was also proposed for overcoming the drawbacks of the widely-used two-phase locking (2PL) CC method. LW DC_k was compared with 2PL and the well-known DWDL (distributed wait-depth limited) CC methods based on the presented simulation system. The application of this simulation system demonstrated its effectiveness. Simulation studies indicated also that the proposed method outperforms 2PL and DWDL.     

Developing adaptable user interfaces for component-based systems

Software components are becoming increasingly popular design and implementation technologies that can be plugged and played to provide user-enhanceable software. However, developing software components with user interfaces that can be adapted to diverse reuse situations is challenging. Examples of such adaptations include extending, composing and reconfiguring multiple component user interfaces, and adapting component user interfaces to particular user preferences, roles and subtasks. We describe our recent work in facilitating such adaptation via the concept of user interface aspects, which support effective component user interface design and realisation using an extended, component-based software architecture.     

Queueing analysis of a server node in transaction processing middleware systems

Quantitative performance modeling of complex information systems is of immense importance for designing enterprise e-business infrastructures and applications. In this paper, we present a traffic model of a server node in a typical transaction processing middleware system as well as a quantitative framework to model and analyze its performance. A multi-class open queueing network model is presented in which multi-class jobs are admitted to a number of server processes sharing hardware resources including the CPU and the disk. We have developed a viable approximation method, which decomposes the dependent components into their independent counterparts while preserving their relevant characteristics. We have conducted queueing-theoretic delay analyses and verified the approach using simulation. Results demonstrate the strength of our approach in predicting delays, elapsed times and other system performance measures.     

On the predictive performance of queueing network models for large-scale distributed transaction processing systems

Automated business processes running on distributed transaction processing (DTP) systems characterize the IT backbone of services industries. New web services standards such as BPEL have increased the importance of DTP systems in business practice. IT departments are forced to meet pre-defined quality-of-service metrics, therefore performance prediction is essential. Unfortunately, the complexity of multiple interacting services running on multiple hardware resources as well as the volatility in the demand for these services can make performance analysis extremely difficult. While business process automation has been a dominant topic in the recent years, surprisingly little has been published on performance modelling of large-scale DTP systems. In this paper, we will describe these systems with respect to the workloads and technical features, and compare the predictive accuracy of different types of queueing models and discrete event simulations experimentally. The experiments are based on two real-world DTP systems and respective data sets of a telecom company. Overall, we found that while the results for average utilization scenarios are quite similar, the effort to implement and run analytic solutions is much lower. As long as standard distributional assumptions of analytical models hold, they provide a reliable and fast methodology to explore different demand mix scenarios even for large-scale systems. The difficulty to estimate service and arrival time parameters and demand mix for the respective queueing network models can largely be reduced with appropriate tooling. Often, this information is missing in IT departments. Also, complex event conditions and error handling in DTP systems can make the analysis difficult. For many DTP applications, however, performance modelling could provide valuable decision support for service level management.     

基于多代理的数据库并行事务处理模型

为了优化一般数据库管理系统的事务处理能力,提出了一种数据库事务并行处理算法。基于多代理技术,建立了一种数据库并行事务处理模型,该模型可以自动识别数据库事务的类别并分配相应的事务代理。通过多代理工具Jade实现了该模型中如事务类型的判别、事务代理的分配、代理的事务处理、结果的返回等基本功能。仿真实验结果表明,对比于传统的单任务事务处理方式,该模型是一种提高数据库事务处理能力的有效方案。     

Avoiding disruptive failovers in transaction processing systems with multiple active nodes

We present a highly available system for environments such as stock trading, where high request rates and low latency requirements dictate that service disruption on the order of seconds in length can be unacceptable. After a node failure, our system avoids delays in processing due to detecting the failure or transferring control to a back-up node. We achieve this by using multiple primary nodes which process transactions concurrently as peers. If a primary node fails, the remaining primaries continue executing without being delayed at all by the failed primary. Nodes agree on a total ordering for processing requests with a novel low overhead wait-free algorithm that utilizes a small amount of shared memory accessible to the nodes and a simple compare-and-swap like protocol which allows the system to progress at the speed of the fastest node. We have implemented our system on an IBM z990 zSeries eServer mainframe and show experimentally that our system performs well and can transparently handle node failures without causing delays to transaction processing. The efficient implementation of our algorithm for ordering transactions is a critically important factor in achieving good performance.     

Real-time control software for transaction processing based on colored safe Petri Net model

A Petri Net-based real-time control software system for transaction processing is proposed to improve flexibility and maintainability in real-time application software. This software system is named Station Controller (SCR). Transaction processing control programs can be understandably described using Control Net (C-net) which is a problem-oriented language based on a colored safe Petri Net model. The described C-net program is directly executed by a net-interpreter installed on a 16-bit micro-computer system. In this paper, some features of the SCR are described and a successful application of the SCR is illustrated.     

An adaptable distributed query processing architecture

Traditionally, distributed query optimization techniques generate static query plans at compile time. However, the optimality of these plans depends on many parameters (such as the selectivities of operations, the transmission speeds and workloads of servers) that are not only difficult to estimate but are also often unpredictable and fluctuant at runtime. As the query processor cannot dynamically adjust the plans at runtime, the system performance is often less than satisfactory. In this paper, we introduce a new highly adaptive distributed query processing architecture. Our architecture can quickly detect fluctuations in selectivities of operations, as well as transmission speeds and workloads of servers, and accordingly change the operation order of a distributed query plan during execution. We have implemented a prototype based on the Telegraph system [Telegragraph project. Available from >]. Our experimental study shows that our mechanism can adapt itself to the changes in the environment and hence approach to an optimal plan during execution.     

A mixed transaction processing and operational reporting benchmark

The importance of reporting is ever increasing in today’s fast-paced market environments and the availability of up-to-date information for reporting has become indispensable. Current reporting systems are separated from the online transaction processing systems (OLTP) with periodic updates pushed in. A pre-defined and aggregated subset of the OLTP data, however, does not provide the flexibility, detail, and timeliness needed for today’s operational reporting. As technology advances, this separation has to be re-evaluated and means to study and evaluate new trends in data storage management have to be provided. This article proposes a benchmark for combined OLTP and operational reporting, providing means to evaluate the performance of enterprise data management systems for mixed workloads of OLTP and operational reporting queries. Such systems offer up-to-date information and the flexibility of the entire data set for reporting. We describe how the benchmark provokes the conflicts that are the reason for separating the two workloads on different systems. In this article, we introduce the concepts, logical data schema, transactions and queries of the benchmark, which are entirely based on the original data sets and real workloads of existing, globally operating enterprises.     

基于角色网络模型的行政事务处理系统控制器

从政府行政事务处理系统存在的问题出发,首先概要综述了角色网络模型（RNM）,进一步提出了动态数学描述。RNM突出了角色的中心位置,充分满足行政事务处理系统的要求,能够对半结构化和非结构化的业务流程进行控制。最后结合MVC架构模式,提出了基于RNM的行政事务处理系统控制器的工作过程。     

A new pseudo-Gaussian-based recurrent fuzzy CMAC model for dynamic systems processing

This article presents a new pseudo-Gaussian-based recurrent fuzzy cerebellar model articulation controller (PG-RFCMAC) model for identifying various nonlinear dynamic systems. A pseudo-Gaussian basis function can provide the self-organising PG-RFCMAC model, which own a higher flexibility and can approach the optimise result more accurately. The pseudo-Gaussian basis function is used to model the hypercube cells and the fuzzy weights. The recurrent network is embedded in the PG-RFCMAC model by adding feedback connections with a receptive field cell, where the feedback units act as memory elements. An on-line learning algorithm is proposed for the automatic construction of the proposed model during the learning procedure. Computer simulations were conducted to illustrate the performance and applicability of the proposed model.     

A parallel logic language for transaction specification in multidatabase systems

The realization of truly heterogeneous database systems is hampered by two principal obstacles. One is the unsuitability of traditional transaction models; this has led to the proposal of a number of new, advanced transaction models. The second is the lack of appropriate programming support for these advanced concepts. This paper addresses these two issues by pointing out the advantages of using a logic-based approach for the integration of autonomous software systems.The work is supported by the Austrian FWF (Fonds zur Förderung der wissenschaftlichen Forschung), project Multidatabase Transaction Processing, contract number P09020-MAT.     

A rule based knowledge transaction model for mobile environments

In this paper, we propose and formalize a rule based knowledge transaction model for mobile environments. Our model integrates the features of both mobile environments and intelligent agents. We use logic programming as a mathematic tool and formal specification method to study knowledge transaction in mobile environments. Our knowledge transaction model has the following major advantages: (1) It can be used for knowledge transaction representation, formalization and knowledge reasoning in mobile environments. (2) It is knowledge oriented and has a declarative semantics inherited from logic programming. (3) It is a formalization that can be applied to general problem domains. We show that our model can be used for knowledge transaction representation, formalization and knowledge reasoning in mobile environments.