This work studies the problem of improving the effectiveness of computing dependent tasks over the Internet. The distributed system is composed of a reliable server that coordinates the computation of a massive number of unreliable workers. It is known that the server cannot always ensure that the result of a task is correct without computing the task itself. This fact has significant impact on...

Currently, the IETF RSerPool WG is standardizing a generic protocol framework for server redundancy and session failover: Reliable Server Pooling (RSerPool). An important property of RSerPool is its lightweight architecture: server pool and session management can be realized with small CPU power and memory requirements. That is, RSerPool-based services can also be managed and provided by embedd...

Reliable Server Pooling (RSerPool) is a protocol framework for server redundancy and session failover, currently under standardization by the IETF RSerPool WG. While the basic ideas of RSerPool are not new, their combination into a single, unified architecture is. Server pooling becomes increasingly important, because there is a growing amount of availability-critical applications. For a servic...

Data replication technique is used to avoid the fault tolerance and improve the performance .With this initiation of content delivery networks, it is becoming more and more frequent that data content is placed on hosts that are not directly controlled by the content owner, and due to this, to ensure the data integrity ,security mechanism are needed. In this paper we present a system architectur...

Aberrant hypo-methylation of DNA is evident in a range of human diseases including cancer and diabetes. Development of sensitive assays capable of detecting traces of un-methylated DNA within methylated samples can be useful in several situations. Here we describe a new approach, fast-COLD-MS-PCR, which amplifies preferentially un-methylated DNA sequences. By employing an appropriate denaturati...

A scalable moving image compression system is proposed for the CAT-SERVER application, MPEG-like in its Group Of Frames structure for pre-dictive coding but using supplementary information retained from previous images to help image prediction and a novel movement detection / coding scheme based on spanning points with associated motion vectors. Résumé : Cet article décrit le système de compres...

RÉSUMÉ. La spécification J2EE (Java 2 platform Enterprise Edition) définit une architecture de serveur d'application Java. Jusqu'à J2EE 1.3, seuls les aspects de déploiement concernant le développeur d'applications étaient adressés. Avec J2EE 1.4, les interfaces et les étapes de déploiement ont été plus précisément spécifiées dans la spécification "J2EE Deployment". JOnAS (Java Open Application...

The number of availability-critical Internet applications is steadily increasing. To support the development and operation of such applications, the IETF has recently defined a new standard for a common server redundancy and session failover framework: Reliable Server Pooling (RSerPool). The basic ideas of the RSerPool framework are not entirely new, but their combination into a single, resourc...

Abstract—The Session Initiation Protocol (SIP) retransmission mechanism is designed to maintain reliable transmission over lossy or faulty network conditions. However, the retransmission can amplify the traffic overload faced by the SIP servers. In this paper, by modeling the interaction between an overloaded downstream server and its upstream server as a feedback control system, we propose two...

The sysctl package is an authenticated client/server system for executing remote commands. It is conceptually similar to rsh, but adds Kerberos[1] authentication, an ACLbased command authorization mechanism, and a programmable Tcl-based[2] command language in its server. The sysctl server component, sysctld, is a daemon that runs on all workstations. The client component lets users send sysctl ...