The Webdamlog System Managing Distributed Knowledge on the Web

We study the use of WebdamLog, a declarative high-level language in the style of datalog, to support the distribution of both data and knowledge (i.e., programs) over a network of autonomous peers. The main novelty of WebdamLog compared to datalog is its use of delegation, that is, the ability for a peer to communicate a program to another peer. We present results of a user study, showing that users can write WebdamLog programs quickly and correctly, and with a minimal amount of training. We present an implementation of the WebdamLog inference engine relying on the Bud datalog engine. We describe an experimental evaluation of the WebdamLog engine, demonstrating that WebdamLog can be implemented efficiently. We conclude with a discussion of ongoing and future work

Rule-Based Application Development using Webdamlog

We present the WebdamLog system for managing distributed data on the Web in a peer-to-peer manner. We demonstrate the main features of the system through an application called Wepic for sharing pictures between attendees of the sigmod conference. Using Wepic, the attendees will be able to share, download, rate and annotate pictures in a highly decentralized manner. We show how WebdamLog handles heterogeneity of the devices and services used to share data in such a Web setting. We exhibit the simple rules that define the Wepic application and show how to easily modify the Wepic application.Comment: SIGMOD - Special Interest Group on Management Of Data (2013

The Story of Webdamlog

International audienceWe summarize in this paper works about the management of data in a distributed manner based on Webdamlog, a datalog-extension. We point to relevant articles on these works. More references may be found there. 1 The Webdamlog approach Information of interest may be found on the Web in a variety of forms, in many systems, and with different access protocols. Today, the control and management of the diversity of data and tasks in this setting are beyond the skills of casual users [1]. Facing similar issues, companies see the cost of managing and integrating information skyrocketing. We are concerned with the management of Web data in place in a distributed manner, with a possibly large number of autonomous, heterogeneous systems collaborating to support certain tasks. We summarize in this paper works in this setting around Webdamlog and point to the relevant articles on it. The thesis is that managing the richness and diversity of data residing on the Web can be tamed using a holistic approach based on a distributed knowledge base. Our approach is to represent all Web information as logical facts, and Web data management tasks as logical rules. A variety of complex data management tasks that currently require intense work and deep expertise may then greatly benefit from the automatic reasoning provided by inference engines, operating over the distributed Web knowledge base: for instance, information access, access control, knowledge acquisition and dissemination. We propose to express the peers logic in Webdamlog, a datalog-style rule-based language. In Webdamlog, peers exchange facts (for information) and rules (in place of code). The use of declarative rules provides the following advantages. Peers may perform automatic reasoning using the available knowledge. Because the model is formally defined, it becomes possible to prove (or disprove) desirable properties. Because the model is based on a datalog-style language, query processing can benefit from optimization techniques. Because the model represents provenance and time, the quality of data can be better controlled. Because We thank all the researchers who participated in the Webdamlog project and in particular

Viewing the Web as a Distributed Knowledge Base

International audienceThis papers addresses the challenges faced by everyday Web users, who interact with inherently heterogeneous and distributed information. Managing such data is currently beyond the skills of casual users. We describe ongoing work that has as its goal the development of foundations for declarative distributed data management. In this approach, we see the Web as a knowledge base consisting of distributed logical facts and rules. Our objective is to enable automated reasoning over this knowledge base, ultimately improving the quality of service and of data. For this, we use Webdamlog, a Datalog-style language with rule delegation. We outline ongoing efforts on the WebdamExchange platform that combines Webdamlog evaluation with communication and security protocols

Gestion des données distribuées avec le langage de règles Webdamlog

Notre but est de permettre à un utilisateur du Web d organiser la gestionde ses données distribuées en place, c est à dire sans l obliger à centraliserses données chez un unique hôte. Par conséquent, notre système diffèrede Facebook et des autres systèmes centralisés, et propose une alternativepermettant aux utilisateurs de lancer leurs propres pairs sur leurs machinesgérant localement leurs données personnelles et collaborant éventuellementavec des services Web externes.Dans ma thèse, je présente Webdamlog, un langage dérivé de datalogpour la gestion de données et de connaissances distribuées. Le langage étenddatalog de plusieurs manières, principalement avec une nouvelle propriété ladélégation, autorisant les pairs à échanger non seulement des faits (les données)mais aussi des règles (la connaissance). J ai ensuite mené une étude utilisateurpour démontrer l utilisation du langage. Enfin je décris le moteur d évaluationde Webdamlog qui étend un moteur d évaluation de datalog distribué nomméBud, en ajoutant le support de la délégation et d autres innovations tellesque la possibilité d avoir des variables pour les noms de pairs et des relations.J aborde de nouvelles techniques d optimisation, notamment basées sur laprovenance des faits et des règles. Je présente des expérimentations quidémontrent que le coût du support des nouvelles propriétés de Webdamlogreste raisonnable même pour de gros volumes de données. Finalement, jeprésente l implémentation d un pair Webdamlog qui fournit l environnementpour le moteur. En particulier, certains adaptateurs permettant aux pairsWebdamlog d échanger des données avec d autres pairs sur Internet. Pourillustrer l utilisation de ces pairs, j ai implémenté une application de partagede photos dans un réseau social en Webdamlog.Our goal is to enable aWeb user to easily specify distributed data managementtasks in place, i.e. without centralizing the data to a single provider. Oursystem is therefore not a replacement for Facebook, or any centralized system,but an alternative that allows users to launch their own peers on their machinesprocessing their own local personal data, and possibly collaborating with Webservices.We introduce Webdamlog, a datalog-style language for managing distributeddata and knowledge. The language extends datalog in a numberof ways, notably with a novel feature, namely delegation, allowing peersto exchange not only facts but also rules. We present a user study thatdemonstrates the usability of the language. We describe a Webdamlog enginethat extends a distributed datalog engine, namely Bud, with the supportof delegation and of a number of other novelties of Webdamlog such as thepossibility to have variables denoting peers or relations. We mention noveloptimization techniques, notably one based on the provenance of facts andrules. We exhibit experiments that demonstrate that the rich features ofWebdamlog can be supported at reasonable cost and that the engine scales tolarge volumes of data. Finally, we discuss the implementation of a Webdamlogpeer system that provides an environment for the engine. In particular, a peersupports wrappers to exchange Webdamlog data with non-Webdamlog peers.We illustrate these peers by presenting a picture management applicationthat we used for demonstration purposes.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

Web information management with access control

International audienceWe investigate the problem of sharing private information on the Web, where the information is hosted on different machines that may use different access control and distribution schemes. We introduce a distributed knowledge-base model, termed WebdamExchange, that comprises logical statements for specifying data, access control, distribution and knowledge about other peers. The statements can be communicated, replicated, queried, and updated, while keeping track of time and provenance. This unified base allows applications to reason declaratively about what data is accessible, where it resides, and how to retrieve it securely

The Webdamlog System -- Managing Distributed Knowledge on the Web

We study the use of WebdamLog, a declarative high-level language in the style of datalog, to support the distribution of both data and knowledge (i.e., programs) over a network of autonomous peers. The main novelty of WebdamLog compared to datalog is its use of delegation, that is, the ability for a peer to communicate a program to another peer. We present results of a user study, showing that users can write WebdamLog programs quickly and correctly, and with a minimal amount of training. We present an implementation of the WebdamLog inference engine relying on the Bud datalog engine. We describe an experimental evaluation of the WebdamLog engine, demonstrating that WebdamLog can be implemented efficiently. We conclude with a discussion of ongoing and future work

Gestion des données distribuées avec le langage de règles Webdamlog

Our goal is to enable aWeb user to easily specify distributed data managementtasks in place, i.e. without centralizing the data to a single provider. Oursystem is therefore not a replacement for Facebook, or any centralized system,but an alternative that allows users to launch their own peers on their machinesprocessing their own local personal data, and possibly collaborating with Webservices.We introduce Webdamlog, a datalog-style language for managing distributeddata and knowledge. The language extends datalog in a numberof ways, notably with a novel feature, namely delegation, allowing peersto exchange not only facts but also rules. We present a user study thatdemonstrates the usability of the language. We describe a Webdamlog enginethat extends a distributed datalog engine, namely Bud, with the supportof delegation and of a number of other novelties of Webdamlog such as thepossibility to have variables denoting peers or relations. We mention noveloptimization techniques, notably one based on the provenance of facts andrules. We exhibit experiments that demonstrate that the rich features ofWebdamlog can be supported at reasonable cost and that the engine scales tolarge volumes of data. Finally, we discuss the implementation of a Webdamlogpeer system that provides an environment for the engine. In particular, a peersupports wrappers to exchange Webdamlog data with non-Webdamlog peers.We illustrate these peers by presenting a picture management applicationthat we used for demonstration purposes.Notre but est de permettre à un utilisateur du Web d’organiser la gestionde ses données distribuées en place, c’est à dire sans l’obliger à centraliserses données chez un unique hôte. Par conséquent, notre système diffèrede Facebook et des autres systèmes centralisés, et propose une alternativepermettant aux utilisateurs de lancer leurs propres pairs sur leurs machinesgérant localement leurs données personnelles et collaborant éventuellementavec des services Web externes.Dans ma thèse, je présente Webdamlog, un langage dérivé de datalogpour la gestion de données et de connaissances distribuées. Le langage étenddatalog de plusieurs manières, principalement avec une nouvelle propriété ladélégation, autorisant les pairs à échanger non seulement des faits (les données)mais aussi des règles (la connaissance). J’ai ensuite mené une étude utilisateurpour démontrer l’utilisation du langage. Enfin je décris le moteur d’évaluationde Webdamlog qui étend un moteur d’évaluation de datalog distribué nomméBud, en ajoutant le support de la délégation et d’autres innovations tellesque la possibilité d’avoir des variables pour les noms de pairs et des relations.J’aborde de nouvelles techniques d’optimisation, notamment basées sur laprovenance des faits et des règles. Je présente des expérimentations quidémontrent que le coût du support des nouvelles propriétés de Webdamlogreste raisonnable même pour de gros volumes de données. Finalement, jeprésente l’implémentation d’un pair Webdamlog qui fournit l’environnementpour le moteur. En particulier, certains adaptateurs permettant aux pairsWebdamlog d’échanger des données avec d’autres pairs sur Internet. Pourillustrer l’utilisation de ces pairs, j’ai implémenté une application de partagede photos dans un réseau social en Webdamlog