Soumitra Sengupta

Managing communication networks by monitoring databases

The problem of managing large communication networks using statistical tests, alerts, and correlation among alerts is considered. The authors propose a model of these network management functions as data-manipulation operations. They argue that this approach can improve the flexibility of network management systems by providing a language that is declarative and set-oriented. These are properties of existing data-manipulation languages and it is shown that any data-manipulation language, augmented with several new capabilities, can serve as a language for specifying the aforementioned network management functions. The new capabilities required are specification of events, correlation among events, and change-tracking. >

NETMATE: A network management environment

A description is given of the Network Management Analysis and Testing Environment (NETMATE) project, the prime goal of which is to develop a unified and comprehensive software environment for network management to oversee and orchestrate the operations of diverse devices and protocols in large, heterogeneous computer networks. The overall NETMATE architecture is discussed, and the network management functions performed by each component are described. The problem of network modeling and the NETMATE approach to it are presented. The current implementation status of NETMATE is given, and some conclusions are offered.<<ETX>>

Modular synchronization in multiversion databases: version control and concurrency control

In this paper we propose a version control mechanism that enhances the modularity and extensibility of multiversion concurrency control algorithms. We decouple the multiversion algorithms into two components: version control and concurrency control. This permits modular development of multiversion protocols, and simplifies the task of proving the correctness of these protocols. An interesting feature of our framework is that the execution of read-only transactions becomes completely independent of the underlying concurrency control implementation. Also, algorithms with the version control mechanism have several advantages over most other multiversion algorithms.

Distributed optimistic concurrency control with reduced rollback

Concurrency control algorithms have traditionally been based on locking and timestamp ordering mechanisms. Recently optimistic schemes have been proposed. In this paper a distributed, multi-version, optimistic concurrency control scheme is described which is particularly advantageous in a query-dominant environment. The drawbacks of the original optimistic concurrency control scheme, namely that inconsistent views may be seen by transactions (potentially causing unpredictable behavior) and that read-only transactions must be validated and may be rolled back, have been eliminated in the proposed algorithm. Read-only transactions execute in a completely asynchronous fashion and are therefore processed with very little overhead. Furthermore, the probability that read-write transactions are rolled back has been reduced by generalizing the validation algorithm. The effects of global transactions on local transaction processing are minimized. The algorithm is also free from dedlock and cascading rollback problems.

Emergency Department Access to a Longitudinal Medical Record

Our goal is to assess how clinical information from previous visits is used in the emergency department. We used detailed user audit logs to measure access to different data types. We found that clinician-authored notes and laboratory and radiology data were used most often (common data types were used up to 5% to 20% of the time). Data were accessed less than half the time (up to 20% to 50%) even when the user was alerted to the presence of data. Our access rate indicates that health information exchange projects should be conservative in estimating how often shared data will be used and the wide breadth of data accessed indicates that although a clinical summary is likely to be useful, an ideal solution will supply a broad variety of data.

Modular synchronization in distributed, multiversion databases: version control and concurrency control

A version control mechanism is proposed that enhances the modularity and extensibility of multiversion concurrency control algorithms. The multiversion algorithms are decoupled into two components: version control and concurrency control. This permits modular development of multiversion protocols and simplifies the task of proving the correctness of these protocols. A set of procedures for version control is described that defines the interface with the version control component. It is shown that the same interface can be used by the database actions of both two-phase locking and time-stamp concurrency control protocols to access multiversion data. An interesting feature of the framework is that the execution of read-only transactions becomes completely independent of the underlying concurrency control implementation. Unlike other multiversion algorithms, read-only transactions in this scheme do not modify any version-related information, and therefore do not interfere with the execution of read-write transactions. The extension of the multiversion algorithms to a distributed environment becomes very simple. >

A Model for Expanded Public Health Reporting in the Context of HIPAA

The advent of electronic medical records and health information exchange raise the possibility of expanding public health reporting to detect a broad range of clinical conditions and of monitoring the health of the public on a broad scale. Expanding public health reporting may require patient anonymity, matching records, re-identifying cases, and recording patient characteristics for localization. The privacy regulations under the Health Insurance Portability and Accountability Act of 1996 (HIPAA) provide several mechanisms for public health surveillance, including using laws and regulations, public health activities, de-identification, research waivers, and limited data sets, and in addition, surveillance may be distributed with aggregate reporting. The appropriateness of these approaches varies with the definition of what data may be included, the requirements of the minimum necessary standard, the accounting of disclosures, and the feasibility of the approach.

IAIMS and sharing

The Integrated Academic Information Management System (IAIMS) concept is about sharing resources and information, and about improving the decision-making ability of health care professionals by integrating information. At Columbia-Presbyterian Medical Center, the IAIMS project has established an information architecture based on common, shared computing and networking resources. The institutional computing culture has been changed with increased sharing of information and, consequently, improved quality of information. Several classes of information in the areas of clinical, scholarly, administrative, basic research, and core resources have been identified for better understanding of information responsibility. Technical problems such as heterogeneity on workstation platforms and lack of universal syntactic and semantic standards for health care information exchange still impede inter-institutional sharing of information.

Infrastructure and Security

Publisher Summary Infrastructure refers to those resources and items required to successfully support and operate information systems. Security refers to policies, procedures, software, and hardware designed to insure that data in information systems are protected against accidental or inappropriate destruction, alteration, or access. Properly supported, infrastructure competency allows an organization to maintain agility in responding to strategic directives and tactical changes. Infrastructure and security together provide the day-to-day operational support for the hardware and software, thus forming a critical component of the organization. Proper management of security requires attention to infrastructure and information system designs, as well as the organization adhering to strict and appropriate personnel practices. Both infrastructure and security are among the many invisible processes and resources required to implement and sustain a successful clinical computing system. Some resources, such as a data center, must be available prior to implementation of these systems; many other resources, such as those supporting security, should be available prior to implementation, but are often deferred until problems occur. Most infrastructure requirements continue and expand after the system is in use. Although organizations can purchase services through outside contracted vendors, those developing skills in their own personnel can use resources more cost effectively, saving as much as 25–40%, particularly in areas such as disaster management. In the longer term, the use of contracted services can result in the loss of skills necessary for making strategic decisions, putting into question whether the estimated savings of contracting can be achieved.

Active Databases for Communication Network Management

Preliminary Version Ouri Wolfson Soumitra Sengupta Yechiam Yemini Distributed Computing and Communication Lab. 450 Computer Science Bldg. Columbia University New York, NY 10027 This paper has two purposes. First is to propose new database language-features for systems used in real-time management. These features enable the specification of change-traces, events and correlation among events, and they do so 10 a declarative set-oriented fashion. Second is to introduce network management as an important and interesting application of active distributed databases.