This paper presents the design and evaluation of Pastry, a scalable, distributed object location and routing substrate for wide-area peer-to-peer ap- plications. Pastry performs application-level routing and object location in a po- tentially very large overlay network of nodes connected via the Internet. It can be used to support a variety of peer-to-peer applications, including global data storage, data sharing, group communication and naming. Each node in the Pastry network has a unique identifier (nodeId). When presented with a message and a key, a Pastry node efficiently routes the message to the node with a nodeId that is numerically closest to the key, among all currently live Pastry nodes. Each Pastry node keeps track of its immediate neighbors in the nodeId space, and notifies applications of new node arrivals, node failures and recoveries. Pastry takes into account network locality; it seeks to minimize the distance messages travel, according to a to scalar proximity metric like the number of IP routing hops. Pastry is completely decentralized, scalable, and self-organizing; it automatically adapts to the arrival, departure and failure of nodes. Experimental results obtained with a prototype implementation on an emulated network of up to 100,000 nodes confirm Pastry's scalability and efficiency, its ability to self-organize and adapt to node failures, and its good network locality properties.

/pdf/pastry-scalable-decentralized-object-location-and-routing-1u2equbbbp.pdf

Pastry: Scalable, Decentralized Object Location, and Routing for Large-Scale Peer-to-Peer Systems

The surface science of titanium dioxide

Satisfiability Modulo Theories (SMT) problem is a decision problem for logical first order formulas with respect to combinations of background theories such as: arithmetic, bit-vectors, arrays, and uninterpreted functions. Z3 is a new and efficient SMT Solver freely available from Microsoft Research. It is used in various software verification and analysis applications.

https://link.springer.com/content/pdf/10.1007%2F978-3-540-78800-3_24.pdf

Z3: an efficient SMT solver

Secret History: Return of the Black Death Channel 4, 7-8pm In 1348 the Black Death swept through London, killing people within days of the appearance of their first symptoms. Exactly how many died, and why, has long been a mystery. This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale. And they ask, what might be coming next?

Medscape

MapReduce and its variants have been highly successful in implementing large-scale data-intensive applications on commodity clusters. However, most of these systems are built around an acyclic data flow model that is not suitable for other popular applications. This paper focuses on one such class of applications: those that reuse a working set of data across multiple parallel operations. This includes many iterative machine learning algorithms, as well as interactive data analysis tools. We propose a new framework called Spark that supports these applications while retaining the scalability and fault tolerance of MapReduce. To achieve these goals, Spark introduces an abstraction called resilient distributed datasets (RDDs). An RDD is a read-only collection of objects partitioned across a set of machines that can be rebuilt if a partition is lost. Spark can outperform Hadoop by 10x in iterative machine learning jobs, and can be used to interactively query a 39 GB dataset with sub-second response time.

/pdf/spark-cluster-computing-with-working-sets-2mqxkxxuqt.pdf

Spark: cluster computing with working sets

Fragment reconstruction is cache coherence protocol for transactional storage systems based on global caching in a network of workstations. It supports fine-grained sharing and works in the presence of object-based concurrency  control algorithm. When transactions commit new versions of objects, stale cached copies of these objects get invalidated. Therefore, pages in a clients cache may become fragments, i.e. contain “holes” corresponding to invalid objects. when such a page is used in the global cache, the coherence protocol fills in the holes using modifications stored in a recoverable cache at the server. Fragment reconstruction is the first coherence protocol that supports fine-grained sharing and global caching in transactional storage systems. Because it is integrated with the recoverable modification cache, it works correctly even in the presence of client failures, and can take advantage of lazy update propagation and update absorption, which is beneficial when pages are updated repeatedly. This paper describes the fragment reconstruction protocol and presents its correctness invariant which insures that only correctly reconstructed fragments are propagated to database.

Fragment Reconstruction: A New Cache Coherence Scheme for Split Caching Storage Systems (Looking at the Doughnut and not the Hole)

Panel discussion: on “The status of the theory of chemical reactions,” Third CISTCP, Mexico City, November 8–13, 1999

What not to expect when you are expecting: a case of infectious endocarditis in a pregnant patient with newly diagnosed obstructive hypertrophic cardiomyopathy

Adsorption of a water molecule on the surface of neutral and charged titanium clusters: Tin-H2O, Tin+1-H2O, Tin-1-H2O, n ≤ 9

Standoff detection of landmines has long been central to improve quality of life in a number of countries around the world. A large body of work in the literature focuses on detection of TNT in soil as central to landmine detection. In this presentation, we summarize our efforts toward detection of TNT, from traces to bulk amounts, based on the absorption fingerprint of TNT. Light absorption by TNT is broken into three regions: (1) visible light absorption by TNT, and (2) formation and detection of NO2 upon UV irradiation of TNT and (3) formation and detection of NO following UV absorption by NO2. The absorption spectrum of TNT powder and particles has been determined from spectral analysis of backscattered visible light in traditional optical and near field optical microscopy measurements, respectively. The smallest amount of TNT detected in the near field measurements is 7 femtograms. The absorption spectra of TNT are rich in structure and similar to the one measured for gas phase NO2, with lines due to roto vibronic coupling of electronic excited states. Measurements of the backscattered visible light on samples, placed about 5 to 10 meters from the laser source, indicate a clear change in intensity as compared to samples containing TNT. Turning to the second light absorption region, NO2 is detected upon UV irradiation of solid TNT. NO can also be detected by photolysis of NO2.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Miguel Castro

Papers

Fragment Reconstruction: A New Cache Coherence Scheme for Split Caching Storage Systems (Looking at the Doughnut and not the Hole)

Panel discussion: on “The status of the theory of chemical reactions,” Third CISTCP, Mexico City, November 8–13, 1999

What not to expect when you are expecting: a case of infectious endocarditis in a pregnant patient with newly diagnosed obstructive hypertrophic cardiomyopathy

Adsorption of a water molecule on the surface of neutral and charged titanium clusters: Tin-H2O, Tin+1-H2O, Tin-1-H2O, n ≤ 9

Nitro explosive detection: from basic science to detection at a distance