Priya Narasimhan

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MapReduce is a programming paradigm for parallel processing that is increasingly being used for data-intensive applications in cloud computing environments. An understanding of the characteristics of workloads running in MapReduce environments benefits both the service providers in the cloud and users: the service provider can use this knowledge to make(More)
Existing network reprogramming protocols target the efficient, reliable, multi-hop dissemination of application updates in sensor networks, but assume correct or fail-stop behavior from participating sensors. Compromised nodes can subvert such protocols to result in the propagation and remote installation of malicious code. Sluice aims for the progressive,(More)
Distributed applications composed of collections of Web services may call for diverse levels of reliability in different parts of the system. Byzantine fault tolerance (BFT) is a general strategy that has recently been shown to be practical for the development of certain classes of survivable, client-server, distributed applications; however, little(More)
It has been almost a decade since the earliest reliable CORBA implementation and, despite the adoption of the FaultTolerant CORBA (FT-CORBA) standard by the Object Management Group, CORBA is still not considered the preferred platform for building dependable distributed applications. Among the obstacles to FT-CORBA’s widespread deployment are the complexity(More)
The Immune system aims to provide survivability to CORBA applications, enabling them to continue to operate despite malicious attacks, accidents, or faults. Every object within the CORBA application is actively replicated by the Immune system, with majority voting applied on incoming invocations and responses to each replica of the object. The Secure(More)
In CORBA-based applications that depend on object replication for fault tolerance, inconsistencies in the states of the replicas of an object can arise when concurrent threads within those replicas perform updates in di erent orders. By imposing a single logical thread of control on every replicated multithreaded CORBA client or server object, and by(More)
The OMG’s Real-Time CORBA (RT-CORBA) and Fault-Tolerant CORBA (FT-CORBA) specifications make it possible for today’s CORBA implementations to exhibit either real-time or fault tolerance in isolation. While real-time requires a priori knowledge of the system’s temporal operation, fault tolerance necessarily deals with faults that occur unexpectedly, and with(More)