Gregory V. Chockler

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View-oriented group communication is an important and widely usedbuilding block for many distributed applications. Much currentresearch has been dedicated to specifying the semantics andservices of view-oriented group communication systems (GCSs).However, the guarantees of different GCSs are formulated usingvarying terminologies and modeling techniques, and(More)
We investigate the problem of designing a scalable overlay network to support decentralized topic-based pub/sub communication. We introduce a new optimization problem, called <i>Minimum Topic-Connected Overlay (Min-TCO)</i>, that captures the tradeoff between the scalability of the overlay (in terms of the nodes' fanout) and the message forwarding overhead(More)
We introduce SpiderCast, a distributed protocol for constructing scalable churn-resistant overlay topologies for supporting decentralized topic-based pub/sub communication. SpiderCast is designed to effectively tread the balance between average overlay degree and communication cost of event dissemination. It employs a novel coverage-optimizing heuristic in(More)
We present Byzantine Disk Paxos, an asynchronous shared-memory consensus protocol that uses a collection of <i>n</i> &gt; 3<i>t</i> disks, <i>t</i> of which may fail by becoming non-responsive or arbitrarily corrupted. We give two constructions of this protocol; that is, we construct two different building blocks, each of which can be used, along with a(More)
The 2008 LADIS workshop on Large Scale Distributed Systems brought together leaders from the commercial cloud computing community with researchers working on a variety of topics in distributed computing. The dialog yielded some surprises: some hot research topics seem to be of limited near-term importance to the cloud builders, while some of their practical(More)
We present an improvement to the Disk Paxos protocol by Gafni and Lamport which utilizes extended functionality and flexibility provided by <i>Active Disks</i> and supports unmediated concurrent data access by an unlimited number of processes. The solution facilitates coordination by an infinite number of clients using finite shared memory. It is based on a(More)
This paper presents a new algorithm for implementing a reconfigurable distributed shared memory in an asynchronous dynamic network. The algorithm guarantees atomic consistency (linearizability) in all executions in the presence of arbitrary crash failures of the processing nodes, message delays, and message loss. The algorithm incorporates a classic(More)
An effective means for building Internet-scale distributed applications, and in particular those involving group-based information sharing, is to deploy peer-to-peer overlay networks. The key pre-requisite for supporting these types of applications on top of the overlays is efficient distribution of messages to multiple subscribers dispersed across numerous(More)
We consider the fault-tolerant consensus problem in wireless ad hoc networks with crash-prone nodes. We develop consensus algorithms for single-hop environments where the nodes are located within broadcast range of each other. Our algorithms tolerate highly unpredictable wireless communication, in which messages may be lost due to collisions,(More)
This paper discusses the implementation of CASCADE, a distributed caching service for CORBA objects. Our caching service is fully CORBA compliant, and supports caching of active objects, which include both data and code. It is speci cally designed to operate over the Internet by employing a dynamically built cache hierarchy. The service architecture is(More)