The ISIS Project: Real Experience with a Fault Tolerant Programming System

The ISIS project has developed a distributed programming toolkit and a collection of higher level applications based on these tools. ISIS is now in use at more than 300 locations world-wise. The lessons (and surprises) gained from this experience with the real world are discussed

The ISIS project: Fault-tolerance in large distributed systems

The semi-annual status report covers activities of the ISIS project during the second half of 1989. The project had several independent objectives: (1) At the level of the ISIS Toolkit, ISIS release V2.0 was completed, containing bypass communication protocols. Performance of the system is greatly enhanced by this change, but the initial software release is limited in some respects. (2) The Meta project focused on the definition of the Lomita programming language for specifying rules that monitor sensors for conditions of interest and triggering appropriate reactions. This design was completed, and implementation of Lomita is underway on the Meta 2.0 platform. (3) The Deceit file system effort completed a prototype. It is planned to make Deceit available for use in two hospital information systems. (4) A long-haul communication subsystem project was completed and can be used as part of ISIS. This effort resulted in tools for linking ISIS systems on different LANs together over long-haul communications lines. (5) Magic Lantern, a graphical tool for building application monitoring and control interfaces, is included as part of the general ISIS releases

Fast casual multicast

A new protocol is presented that efficiently implements a reliable, causally ordered multicast primitive and is easily extended into a totally ordered one. Intended for use in the ISIS toolkit, it offers a way to bypass the most costly aspects of ISIS while benefiting from virtual synchrony. The facility scales with bounded overhead. Measured speedups of more than an order of magnitude were obtained when the protocol was implemented within ISIS. One conclusion is that systems such as ISIS can achieve performance competitive with the best existing multicast facilities--a finding contradicting the widespread concern that fault-tolerance may be unacceptably costly

ISIS in America: A Sociohistorical Analysis

During the summer of 2014, the terrorist organization Islamic State (commonly referred to as Islamic State in Iraq and Syria, or ISIS) garnered international attention after its unprecedented territorial acquisitions and violence in the Middle East. Today, ISIS vies with al-Qaeda for leadership of the global Islamic Extremist movement and has extended its violence all over the world, including the United States. U.S. based supporters generally choose to engage with the ideology in one of three categories: as a foreign fighter, domestic plotter, or domestic non-plotter. Despite this threat, there is very little quantitative research concerning U.S. ISIS supporters and the incidents they plan. Utilizing data from the American Terrorism Study (ATS), the current study compares ISIS perpetrators across the three support type categories, as well as ISIS and al-Qaeda and Associated Movements (AQAM) affiliated persons and incidents in the United States. I conducted Chi Square and Conjunctive Analysis of Case Configurations to determine significant differences. The analysis indicated significant difference across ISIS support types with regard to gender and age of the individuals, and suggested common patterns in the types of individuals who choose to leave the U.S. or stay and engage in violence. Additional analysis indicated significant differences in the residency status and race between ISIS and AQAM perpetrators. Finally, results showed that, although ISIS and AQAM incidents have different configurations concerning targets, weapons, and group size, their success rates are relatively the same. In conclusion, there are important differences between ISIS and AQAM affiliated persons and incidents that may merit considering them as separate entities rather than together under the umbrella of Islamic Extremist

Three lepton signatures from tZq interactions in the SM and top-FCNC at the CMS experiment at \sqrt{s} = 8 TeV

The search for a top quark in association with a Z boson can be performed in both top pair production as well as single top production. Targeting the three lepton final state, the search can be used to identify the standard model (SM) process of a single top quark associated with a Z boson and to search for flavour changing neutral current (FCNC) interactions. The presented analysis uses a data sample corresponding to an integrated luminosity of $19.7$ fb$^{-1}$ recorded by the CMS experiment at the LHC in proton collisions at $\sqrt{s}=8$ TeV. The cross section for the SM tZq production is measured to be $\sigma(tZq\rightarrow l\nu bl^+ l^- q)= 10^{+8}_{-7}$ fb with a significance of $2.4 \sigma$. Exclusion limits at 95$\%$ confidence level on the branching ratio of a top quark decaying to a Z boson and an up or charm quark are determined to be $BR(t \rightarrow Zu) < 0.022\%$ and $BR(t \rightarrow Zc) < 0.049\%$ respectively.Comment: Presented at the 9th International Workshop on Top Quark Physics, Olomouc, Czech Republic, September 19-23, 201

Programming your way out of the past: ISIS and the META Project

The ISIS distributed programming system and the META Project are described. The ISIS programming toolkit is an aid to low-level programming that makes it easy to build fault-tolerant distributed applications that exploit replication and concurrent execution. The META Project is reexamining high-level mechanisms such as the filesystem, shell language, and administration tools in distributed systems