Aspen Olmsted

Grade calculation in historical educational environments depends on a grade journal that is only visible to the instructor. In modern educational environments, this journal has been replaced by more transparency in the form of a computerized learning management system. Unfortunately, there are not correctness guarantees for the students and the faculty. Relational databases measured correctness guarantees with ACID (Atomic, consistency, isolation, and durability) properties. These guarantees… Show more

Grade calculation in historical educational environments depends on a grade journal that is only visible to the instructor. In modern educational environments, this journal has been replaced by more transparency in the form of a computerized learning management system. Unfortunately, there are not correctness guarantees for the students and the faculty. Relational databases measured correctness guarantees with ACID (Atomic, consistency, isolation, and durability) properties. These guarantees are missing in distributed learning management systems. In the research, tools and algorithms are developed that can guarantee consistency and durability client side, inside a web browser, on behalf of the student and the faculty. Show less

In this paper we investigate the problem of providing consistency, availability and durability for Web Service transactions. We consider enforcement of integrity constraints in a way that increases the availability while guaranteeing the correctness specified in the constraint. We study hierarchical constraints that offer an opportunity for optimization because of an expensive aggregation calculation required in the enforcement of the constraint. We propose an approach that guarantees… Show more

In this paper we investigate the problem of providing consistency, availability and durability for Web Service transactions. We consider enforcement of integrity constraints in a way that increases the availability while guaranteeing the correctness specified in the constraint. We study hierarchical constraints that offer an opportunity for optimization because of an expensive aggregation calculation required in the enforcement of the constraint. We propose an approach that guarantees enforcement of constraints and also allow the distribution of write operations among many clusters to increase the availability. In our previous work, we proposed a replica update propagation method, called the Buddy System, which guaranteed durability and increased availability of web services. In this paper, we extend the Buddy System to enforce hierarchical data integrity constraints. Show less

In this paper we investigate the problem of providing consistency, availability and durability for web service transactions. We propose an approach that matches the availability of the popular lazy replica update propagation method while increases the durability and consistency. Our replica update propagation method is called the Buddy System, which requires that updates are preserved synchronously in two replicas. Our first implementation schedules fine-grained WS transactions. In these… Show more

In this paper we investigate the problem of providing consistency, availability and durability for web service transactions. We propose an approach that matches the availability of the popular lazy replica update propagation method while increases the durability and consistency. Our replica update propagation method is called the Buddy System, which requires that updates are preserved synchronously in two replicas. Our first implementation schedules fine-grained WS transactions. In these transactions each activity is a low level database operation. Later we consider each transaction as a black box, with only the corresponding metadata, expressed as UML specifications, as transaction semantics. We refer to these WS transactions as coarse-grained WS transactions. The Buddy System is able to handle these course grained WS transactions, using UML stereotypes that allow scheduling semantics to be embedded into the design model. We show that our approach guarantees one-copy serializability, matches the performance of the lazy update propagation methods, and increases durability in the presence of hardware failures. Show less

In this paper we investigate the problem of providing consistency, availability and durability for Web Service transactions. We consider enforcement of integrity constraints in a way that increases availability while guaranteeing the correctness specified in the constraint. We study hierarchical constraints that offer an opportunity for optimization because of an expensive aggregation calculation required in the enforcement of the constraint. We propose an approach that guarantees that the… Show more

In this paper we investigate the problem of providing consistency, availability and durability for Web Service transactions. We consider enforcement of integrity constraints in a way that increases availability while guaranteeing the correctness specified in the constraint. We study hierarchical constraints that offer an opportunity for optimization because of an expensive aggregation calculation required in the enforcement of the constraint. We propose an approach that guarantees that the constraint cannot be violated and also allow the distribution of write operations among many clusters to increase availability. In our previous work, we proposed a replica update propagation method, called the Buddy System, which guaranteed durability and increased availability of web services. In this paper we extend the Buddy System to enforce hierarchical data integrity constraints. Show less

In this paper we investigate the problem of providing consistency, availability and durability for Web Service-transactions. We consider each transaction as a black box, with only the corresponding metadata, expressed as UML specifications, as transaction semantics. We refer to these WS transactions as coarse-grained WS-transactions. We propose an approach that guarantees the availability of the popular lazy replica update propagation method while increasing the durability and consistency. In… Show more

In this paper we investigate the problem of providing consistency, availability and durability for Web Service-transactions. We consider each transaction as a black box, with only the corresponding metadata, expressed as UML specifications, as transaction semantics. We refer to these WS transactions as coarse-grained WS-transactions. We propose an approach that guarantees the availability of the popular lazy replica update propagation method while increasing the durability and consistency. In our previous work, we proposed a replica update propagation method, called Buddy System, which required that updates are preserved synchronously in two replicas. In this paper we extend the Buddy System to handle course grained WS transactions, using UML stereotypes that allow scheduling semantics to be embedded into the design model. This design model is then exported and consumed by a service dispatcher to provide: 1.) High availability by distributing service requests across all available clusters. 2.) Consistency by performing the complete transaction on a single set of clusters. 3.) Durability by updating two clusters synchronously. Show less

In this paper we investigate the problem of providing consistency, availability and durability for Web Service transactions that consume anonymous and attribute based resources. We show that the availability of the popular lazy replica update propagation method can be achieved while increasing it's durability and consistency. Our approach is based on an extension to the Buddy System, requiring that updates are preserved synchronously in two replicas, called buddies. Our system provides a new… Show more

In this paper we investigate the problem of providing consistency, availability and durability for Web Service transactions that consume anonymous and attribute based resources. We show that the availability of the popular lazy replica update propagation method can be achieved while increasing it's durability and consistency. Our approach is based on an extension to the Buddy System, requiring that updates are preserved synchronously in two replicas, called buddies. Our system provides a new consistency constraint, Capacity Constraint, which allows the system to guarantee that resources are not over consumed and also allows for higher distribution of the consumption. Our method provides 1.) higher availability through the distribution of element master's by utilizing all available clusters, 2.) consistency by performing the complete transaction on a single set of clusters, and 3.) a guaranteed durability by updating two clusters synchronously with the transaction. Show less

gLIMS is a laboratory information management system and community-driven spectroscopic annotation system for the field of metabolomics, which is the study of the of the identifying products left behind by the process of metabolism. gLIMS provides services and interfaces for exposing nuclear magnetic resonance (NMR) spectral annotations to the Semantic Web. The ability to plot and annotate spectra enables the metabolomics community to improve analysis and subsequent scientific discovery. gLIMS is… Show more

gLIMS is a laboratory information management system and community-driven spectroscopic annotation system for the field of metabolomics, which is the study of the of the identifying products left behind by the process of metabolism. gLIMS provides services and interfaces for exposing nuclear magnetic resonance (NMR) spectral annotations to the Semantic Web. The ability to plot and annotate spectra enables the metabolomics community to improve analysis and subsequent scientific discovery. gLIMS is flexible, efficient, available, and easy to integrate with scientific workflow software by providing a representational state transfer (RESTful) web service interface that allows researchers to view, interpret, and then annotate significant metabolites on NMR spectroscopic data. gLIMS exposes spectra and metabolomics annotation metadata and provenance to the Semantic Web through the Resource Description Framework (RDF) which allows the system to integrate with Linked Data and be queried via SPARQL. This system is implemented using Google’s platform as a service (PAAS) technologies and Google Drive to produce a robust, scalable, and extensible lab information management system running entirely in-browser which facilitates collaboration on a worldwide scale. Show less

In this paper we investigate the problem of providing durability for Web Service transactions in the presence of system failures. We show that the popular lazy replica update propagation method is vulnerable to loss of transactional updates in the presence of hardware failures. We propose an extension to the lazy update propagation approach to reduce the risk of data loss. Our approach is based on the “buddy” system, requiring that updates are preserved synchronously in two replicas, called… Show more

In this paper we investigate the problem of providing durability for Web Service transactions in the presence of system failures. We show that the popular lazy replica update propagation method is vulnerable to loss of transactional updates in the presence of hardware failures. We propose an extension to the lazy update propagation approach to reduce the risk of data loss. Our approach is based on the “buddy” system, requiring that updates are preserved synchronously in two replicas, called buddies. The rest of the replicas are updated using lazy update propagation protocols. Our method provides a balance between durability (i.e., effects of the transaction are preserved even if the server, executing the transaction, crashes before the update can be propagated to the other replicas) and efficiency (i.e., our approach requires a synchronous update between two replicas only, adding a minimal overhead to the lazy replication protocol). Moreover, we show that our method of selecting the buddies ensures correct execution and can be easily extended to balance workload, and reduce latency observable by the client. Show less

Our project is a scalable community-driven spectroscopic annotation system for the field of metabolomics, which is the study of the of the identifying products left behind by the process of metabolism. This project is a Google-based laboratory information management system or gLIMS. This system combines the intuitive Google Drive interface and storage system with applications that empower the data, including data-visualization, annotation, and exposure to the semantic web. The value of this… Show more

Our project is a scalable community-driven spectroscopic annotation system for the field of metabolomics, which is the study of the of the identifying products left behind by the process of metabolism. This project is a Google-based laboratory information management system or gLIMS. This system combines the intuitive Google Drive interface and storage system with applications that empower the data, including data-visualization, annotation, and exposure to the semantic web. The value of this system is its ability to view, interpret, and then annotate significant metabolites on nuclear magnetic resonance spectroscopic data. gLIMS overcomes shortcomings in currently available software, which are proprietary, closed, fail to offer web services and workflow integration, or do not have collaboration tools for scientists. The ability to plot and annotate spectra enables the metabolomics community to improve analysis and subsequent scientific discovery. The system is flexible, efficient, available, and easy to integrate with scientific workflow software by providing a representational state transfer (RESTful) web service interface. This system is implemented using Google's platform as a service (PAAS) technologies to produce a robust, available, scalable, and extensible lab information management system running entirely in-browser which facilitates collaboration on a worldwide scale. Show less

Most vertical market applications use 80% of their development resources building standard CRM functionality and only 20% on the rest. A smarter solution might be to distribute your vertical market application along with SugarCRM, and focus your development efforts on your specific line-of-business requirements instead