CovaTM

ACID (Atomicity, Consistency, Isolation and Durability) properties characterize the initial transactional model (TM). Being too restrictive and functionally limited to face the requirements of more recent application domains, the semantics of these properties has been relaxed (weakened) leading to an important set of TMs. Understanding, comparing and synthesizing TMs on the basis of core features and, more specifically, understanding and comparing relaxed ACID properties to be able to reuse them, during the synthesis of TMs, is still an unreached goal. The ACTA framework represented a relevant step towards the achievement of that goal. ACTA, however, as we contribute in highlighting, presents several points of weakness. To contribute in easing the identification and specification of reusable and composable commonalities and variabilities among TMs, we introduce a software product line oriented, ACTA-based, language, called SPLACID. SPLACID is dedicated to the formal specification of TMs in terms of the selection and specialisation of a set of TM standard features. SPLACID promotes reuse and enhance rigor and precision by providing a well structured concrete syntax.

Nowadays it has been widely recognized that traditional transaction models with ACID (Atomicity, Consistency, Isolation and Durability) properties generally are not applicable to cooperative applications. To solve this problem, a new transaction model called CovaTM is proposed. CovaTM views one execution of a cooperative process as a transaction with its sub-transactions corresponding to activities. It provides sophisticated but flexible control over cooperative process and relaxes the restrictions on atomicity and isolation. Therefore, it can meet the requirements of cooperative applications well. This paper details the implementation issues of CovaTM including how to construct a transaction according to the cooperative process description as well as the mechanism and algorithm adopted at runtime.

In central databases the consistency of data is normally implemented by using the ACID (Atomicity, Consistency, Isolation and Durability) properties of a DBMS (Data Base Management System). This is not possible if distributed and/or mobile databases are involved and the availability of data also has to be optimized. Therefore, we will in this paper use so called relaxed ACID properties across different locations. The objective of designing relaxed ACID properties across different database locations is that the users can trust the data they use even if the distributed database temporarily is inconsistent. It is also important that disconnected locations can operate in a meaningful way in so-called disconnected mode.A database is DBMS consistent if its data complies with the consistency rules of the DBMS's metadata. If the database is DBMS consistent both when a transaction starts and when it has been committed and completed, the execution has the consistency property.The above definition of the consistency property is not useful in distributed databases with relaxed ACID properties because such a database is almost always inconsistent.In the following, we will use the concept Consistency anomalies for the inconsistencies caused by the missing consistency property in distributed integrated databases with relaxed ACID properties.In this paper, we will describe countermeasures against the consistency anomalies to make it possible to reduce or prevent the consequences of the missing distributed consistency property. We will also illustrate how to use the countermeasures against the consistency anomalies in ERP systems integrated with heterogeneous E-commerce systems and the databases of mobile salesman ERP modules.The methods described in this paper may be used in so called CAP optimization where Availability and Partition-tolerance are optimized on the expense of Consistency

SUMMARYIn modern transaction processing software, the ACID properties (atomicity, consistency, isolation, durability) are often relaxed, in order to address requirements that arise in computing environments of today. Typical examples are the long‐running transactions in mobile computing, in service‐oriented architectures and B2B collaborative applications. These new transaction models are collectively known as advanced or extended transactions. Formal specification and reasoning for transaction properties have been limited to proof‐theoretic approaches, despite the recent progress in model checking. In this work, we present a model‐driven approach for generating a provably correct implementation of the transaction model of interest. The model is specified by state machines for the transaction participants, which are synchronized on a set of events. All possible execution paths of the synchronized state machines are checked for property violations. An implementation for the verified transaction model is then automatically generated. To demonstrate the approach, the specification of nested transactions is verified, because it is the basis for many advanced transaction models. Concurrency and Computation: Practice and Experience. Copyright © 2012 John Wiley & Sons, Ltd.

Workflow management systems (WFMSs) are finding wide applicability in small and large organizational settings. Advanced transaction models (ATMs) focus on maintaining data consistency and have provided solutions to many problems such as correctness, consistency, and reliability in transaction processing and database management environments. While such concepts have yet to be solved in the domain of workflow systems, database researchers have proposed to use, or attempted to use ATMs to model workflows. In this paper we survey the work done in the area of transactional workflow systems. We then argue that workflow requirements in large-scale enterprise-wide applications involving heterogeneous and distributed environments either differ or exceed the modeling and functionality support provided by ATMs. We propose that an ATM is unlikely to provide the primary basis for modeling of workflow applications, and subsequently workflow management. We discuss a framework for error handling and recovery in the METEOR2 WFMS that borrows from relevant work in ATMs, distributed systems, software engineering, and organizational sciences. We have also presented various connotations of transactions in real-world organizational processes today. Finally, we point out the need for looking beyond ATMs and using a multi-disciplinary approach for modeling large-scale workflow applications of the future.

THE Internet, along with its related technologies, has created an interconnected world in which information flows easily and tasks are processed collaboratively. To make service-oriented applications more robust, Web services must be examined from a transactional perspective. By transactional, we mean first defining the actions that guide the execution of Web services when failures arise and then the states that permit claiming the success of this execution following the handling of these failures. A variety of transactional models are reported in the database community. Some of these models can be leveraged and enhanced in response to Web services characteristics while others are not suitable for Web services due to the dynamic nature of Web services, the long-running execution scenarios that Web services take part in, and the successful execution of Web services despite other peers’ failure. Today’s service-oriented applications require advanced transactional models that guarantee integrity and continuity of business processes despite the dynamic nature of the features of the environments hosting the execution of these applications. This special section sheds light on the latest advances in the fields of Web services and transactional models in order to better address advanced research on and experience with transactional Web services. Four papers out of 19 submissions were selected for inclusion in this special section. Each submission was subject to a double-review process by at least three peer reviewers. In the first paper, entitled “Event-Based Design and Runtime Verification of Composite Service Transactional Behavior,” Gaaloul et al. propose an event-driven approach to validate the transactional behavior of Web services taking part in compositions. A composition life cycle consists of four phases, namely, design, execution, monitoring, and reengineering. The verification of this behavior throughout this life cycle is done either at design time to validate recovery mechanisms’ consistency or after runtime to detect execution deviations and repair design errors, and, therefore, formally ensure the execution reliability of Web services. In addition, this verification is based on the Event Calculus formalism, which offers a sound definition for this reliability. In the second paper, entitled “FACTS: A Framework for Fault-Tolerant Composition of Transactional Web Services,” Liu et al. note that delivering reliable compositions over unreliable Web services is challenging. To address this challenge, Liu et al. identify a set of high-level exception handling strategies and a new taxonomy of transactional Web services to devise a fault-tolerant mechanism that combines exception handling and transaction techniques. In addition, Liu et al. devise two modules, known as specification and verification, to assist service designers in constructing fault handling logic conveniently and correctly. This logic is automatically injected into WS-BPEL. In the third paper, entitled “Rule-Based Coordination of Distributed Web Service Transactions,” von Riegen et al. study the distributed transactional activity control problem in the context of service choreographies. In such a context, many participants are allowed to work together to achieve a global, common goal, and the initiator of a process is not always the one who is able to commit or cancel a transaction. Von Riegen et al. introduce a framework that allows autonomous coordination of dynamic processes. This framework extends WSBusinessActivity to strengthen the role of the coordinator. Predicate rules are developed to let participants cancel or complete a process and help the coordinators decide on the completion processes and the confirmation or cancellation of the participants’ works. In the fourth paper, entitled “TQoS: Transactional and QoS-Aware Selection Algorithm for Automatic Web Service Composition,” El Haddad et al. focus on the issues of selecting and composing Web services. A design-time selection algorithm is proposed in which transactional and QoS requirements are both integrated into the selection process. This algorithm is based on the notion of risk that indicates if execution outcomes can either be compensated for or not. Two risk levels of execution in a transactional system are considered: Risk 0, meaning that if the execution is successful, the obtained outcomes can be compensated for by the user, and Risk 1, meaning that the system does not guarantee successful execution, but if it achieves it, the outcomes cannot be compensated for by the user. We hope this special section inspires researchers to develop new transactional models that would guarantee service-oriented applications integrity and continuity. 30 IEEE TRANSACTIONS ON SERVICES COMPUTING, VOL. 3, NO. 1, JANUARY-MARCH 2010

The objective of the logistics management and control in a transport enterprise is to plan for the cheapest way to fulfill the transport needs of the customers and to offer the service to the customer so that, at any time, they know where their products are in the transport process. In case of delays in their transports, it is very important to have the possibility of informing customers as soon as possible in order for them to fulfill their obligations. This paper describes an architecture for mobile integrated logistics management and control where performance, local autonomy and availability are optimized by using relaxed ACID (Atomicity, Consistency, Isolation and Durability) properties and different asynchronous replication methods, and where it also is possible to make integration with stationary systems like the ERP system of the transport enterprise itself and the ERP systems of cooperating transport operators.

Transactional dependencies play an important role in coordinating the execution of subtransactions in advanced transaction models, such as, nested transactions and workflow transactions. The correct execution of the advanced transactions depends on ensuring the satisfaction of all the dependencies, which are specified by the application developer. Incorrect specification of transaction dependencies might lead to information integrity problems and unavailability of resources. An example of incorrect specification of dependencies is the presence of conflicts - the satisfaction of constraints imposed by one dependency may violate the constraints imposed by another dependency. Algorithms that can analyze and detect dependency conflicts are necessary. Although a lot of research appears on advanced transactions, no previous work has been done on analysis of dependency conflicts. In this work, we analyze different kinds of dependency conflicts, propose algorithms to detect and remove the conflicts of dependencies in advanced transaction specifications. This will enable the application developer to get assurance about the correctness of the dependency specification and the correct behavior of the underlying advanced transaction model.

This paper is an overview of the Exotica project, currently in progress at the IBM Almaden Research Center. The project aims at exploring several research areas from advanced transaction management concepts to client/server architectures and mobile computing within the context of business processes and workflow management. The ultimate goal is to incorporate these ideas into IBM's products and prototypes. The project involves IBM groups in Almaden (U.S.A.), Hursley (U.K.), Boeblingen (Germany), and Vienna (Austria). In this paper we briefly describe two IBM products, FlowMark, a workflow management system, and MQSeries, a messaging system, as the environments in which we are focusing our research. We also discuss some of our results in the areas of availability, replication, distribution, and advanced transaction models, as well as describe our future research directions. 10

Web service composition is used as subprocess in the workflow system. If the workflow can provide high reliability and constituency through transaction process technology, the composition of Web service and workflow will be the main solution to solve problem of e-business. Traditional transaction model lacks support for long-running transaction in application of Web service. From the angel of the tier relation between Web service composition and separated Web service that is part of Web service composition, a transaction model based on precontract and semantics encapsulation is presented to improve the efficiency of Web service-based transaction process.

Process Modelling (PM) is a software engineering discipline that aims at supporting the development of large and complex software systems. Therefore, PM focusses on study, de nition, enaction, and possibly improvement of software process models. Traditional transaction management (TM) protects data against unexpected system failures, con icts or inconsistencies. TM is also used in other areas, such as software engineering, to provide concurrency control and failure recovery for both automatic and manual activities. Transactions are typically used to provide reliable working contexts for software developers and for PM systems that enact process models. Software engineering TM adds requirements, such as support to user interaction, long lasting activities, non-programmed operations in the context of one transaction, and activity coordination. In this paper we will look at some aspects of using transaction technology to support enaction of software process models. We de ne a simple transaction model and then discuss various ways transactions can be used in enacting the ISPW '6 PM example problem [KFF90]. The focus of the discussion will be on structural aspects of both process models and transaction models. We identify problem areas, requirements to transaction models and choice-points in enacting a process model. By looking at process models, we nd that more information about the enaction must be speci ed to be able to map it to a single execution of a set of transactions. The structure of the paper is as follows: We rst present some PM terminology and the ISPW '6 PM example problem. We then turn to transaction models and introduce a simple model typical for the class of transaction models used in PM systems. The next section discusses how parts of the example problem can be enacted in terms of issuing transactions against a database containing the software objects used in the example.

Numerous extended transaction models have been proposed in the literature to overcome the limitations of the traditional transaction model for advanced applications characterized by their long durations, cooperation between activities and access to multiple databases (like CAD/CAM and office automation). However, most of these extended models have been proposed with specific applications in mind and almost always fail to support applications with slightly different requirements. We propose the Multiform Transaction model to overcome this limitation. The multiform transaction model supports a variety of other extended transaction models. A multiform transaction consists of a set of component transactions together with a set of coordinators which specify the transaction completion dependencies among the component transactions. A set of transaction primitives allow the programmer to define custom completion dependencies. We show how a wide range of extended transactions can be implemented as multiform transactions, including sagas, transactional workflows, nested transactions, and contingent transactions. We allow the programmers to define their own primitives—having very well-defined interfaces—so that application specific transaction models like distributed multilevel secure transactions can also be supported.

Open Multithreaded Transactions form an advanced transaction model that provides features for controlling and structuring not only accesses to objects, as usual in transaction systems, but also threads taking part in transactions. The model allows several threads to enter the same transaction in order to perform a joint activity. It provides a flexible way of manipulating threads executing inside a transaction by allowing them to be forked and terminated, but it restricts their behavior in order to guarantee correctness of transaction nesting and isolation among transactions. In addition, transactions are exception handling contexts, and the model therefore provides forward and backward error recovery. In this paper we show that the model is indeed powerful, and that a complex application, i.e. an online auction system, can be designed and implemented in a very elegant way.

Global cross-border trade payments involve complex transactional networks, multiple counterparties, and diverse regulatory environments, exposing financial institutions to operational, credit, and compliance risks. Traditional risk management approaches often rely on static rules or post-event reconciliation, limiting the ability to proactively detect potential anomalies and optimize liquidity. This presents an AI-Driven Risk Scoring Model designed to enhance risk management for global cross-border trade payment transactions by integrating predictive analytics, machine learning algorithms, and multi-dimensional data inputs. The proposed model leverages historical payment data, counterparty profiles, transaction metadata, and regulatory compliance information to generate dynamic risk scores for individual transactions in real time. Machine learning techniques, including supervised and unsupervised models, identify patterns indicative of delayed settlements, anomalous behavior, or potential non-compliance. The risk scores enable institutions to prioritize monitoring, allocate liquidity efficiently, and take proactive mitigation measures before high-risk events materialize. A core feature of the model is its integration with operational and compliance workflows. Risk assessment is embedded directly into transaction processing systems, enabling automated alerts, conditional settlement logic, and exception handling. The model also supports regulatory oversight by providing transparent, audit-ready risk metrics that align with AML/KYC standards, sanctions screening, and reporting obligations. This demonstrates that AI-driven risk scoring can significantly improve the predictive accuracy of transaction risk identification, reduce operational delays, and enhance decision-making for cross-border payment settlements. Furthermore, the model’s scalability allows financial institutions to extend their application across multiple jurisdictions, currencies, and trade networks, addressing the challenges of a globally interconnected payment ecosystem. The AI-Driven Risk Scoring Model represents a transformative approach to managing risk in global cross-border trade payments. By combining predictive analytics, machine learning, and real-time integration with operational and compliance systems, the model provides financial institutions with actionable insights, enhanced oversight, and optimized liquidity management, supporting resilient and future-ready trade finance operations.

Distributed transaction model has gradually replaced the traditional centralized transaction model and has become the leading direction of development in energy trading. As the underlying support, blockchain technology is attracting more and more attention due to its advantages, i.e., integrity and non-repudiation. However, most blockchain-based trading models face the problem of privacy protection. In this paper, to solve this problem, Ciphertext-Policy Attribute-Based Encryption (CP-ABE) is introduced as the core algorithm to reconstruct the transaction model. Specifically, we build a general model for distributed transaction called PP-BCTS (Privacy- Preserving Blockchain Trading Scheme). It can achieve fine-grained access control through transaction arbitration in ciphertext form. This design can maximize the protection of private information and can greatly improve the security and reliability of the transaction model. Additionally, a credibility-based equity proof consensus mechanism is proposed in PP-BCTS, which can greatly improve the operational efficiency. Security analysis and experimental evaluations are conducted to prove the validity and practicability of our proposed scheme.