On a Multiprocessor Computer Farm for Online Physics Data Processing

The topic of this thesis is the design-phase performance evaluation of a large multiprocessor (MP) computer farm intended for the on-line data processing of the Compact Muon Solenoid (CMS) experiment. CMS is a high energy Physics experiment, planned to operate at CERN (Geneva, Switzerland) during the year 2005. The CMS computer farm is consisting of 1,000 MP computer systems and a 1,000 X 1,000 communications switch. The followed approach to the farm performance evaluation is through simulation studies and evaluation of small prototype systems building blocks of the farm. For the purposes of the simulation studies, we have developed a discrete-event, event-driven simulator that is capable to describe the high-level architecture of the farm and give estimates of the farm's performance. The simulator is designed in a modular way to facilitate the development of various modules that model the behavior of the farm building blocks in the desired level of detail. With the aid of this simulator, we make a particular study on the scheduling of the nodes of the farm, showing that a preemptive scheduling can increase farm's throughput. We have developed a prototype setup of a farm node an event filter unit. The setup consists of a high performance MP system (the farm node) connected to a second computer system (used to emulate the data sources) through an ATM network. The performance issues of interfacing a network interface controller (NIC) to the application running in the farm node, are explored. It is shown with the aid of this setup, that the switch-to-farm interface (SFI) a device used to put together the incoming data fragments into a single entity can be entirely avoided by emulating its function in software. We show that in order to meet the required event assembly performance in the filter node inputs, the development effort has to concentrate on the NIC hardware, software and its interface to the application, rather than building a custom designed device specialized to perform the task of event assembly. Finally, the farm scaling issues are investigated. Our aim is to obtain an "operational region" inside the farm configuration space, when the various networking speeds are taken into account. Analytically obtained results that have been confirmed with the above mentioned simulator, are discussed. We present also results showing the influence 8 of the inherent to the farm parameters (like the algorithm rejection factor) on the requirements for the farm building blocks (sustained I/O bandwidth) of the inherent to the farm parameters (like the algorithm rejection factor) on the requirements for the farm building blocks (sustained I/O bandwidth)

The CMS event builder demonstrator based on Myrinet

The data acquisition system for the CMS experiment at the Large Hadron Collider (LHC) will require a large and high performance event building network. Several switch technologies are currently being evaluated in order to compare different architectures for the event builder. One candidate is Myrinet. This paper describes the demonstrator which has been set up to study a small-scale (8*8) event builder based on a Myrinet switch. Measurements are presented on throughput, overhead and scaling for various traffic conditions. Results are shown on event building with a push architecture. (6 refs)

The Oncology Care Model: Perspectives From the Centers for Medicare & Medicaid Services and Participating Oncology Practices in Academia and the Community

Cancer care delivery in the United States is often fragmented and inefficient, imposing substantial burdens on patients. Costs of cancer care are rising more rapidly than other specialties, with substantial regional differences in quality and cost. The Centers for Medicare & Medicaid Services (CMS) Innovation Center (CMMIS) recently launched the Oncology Care Model (OCM), which uses payment incentives and practice redesign requirements toward the goal of improving quality while controlling costs. As of March 2017, 190 practices were participating, with approximately 3,200 oncologists providing care for approximately 150,000 unique beneficiaries per year (approximately 20% of the Medicare Fee-for-Service population receiving chemotherapy for cancer). This article provides an overview of the program from the CMS perspective, as well as perspectives from two practices implementing OCM: an academic health system (Yale Cancer Center) and a community practice (Hematology Oncology Associates of Central New York). Requirements of OCM, as well as implementation successes, challenges, financial implications, impact on quality, and future visions, are provided from each perspective

A software approach for readout and data acquisition in CMS

Traditional systems dominated by performance constraints tend to neglect other qualities such as maintainability and configurability. Object-Orientation allows one to encapsulate the technology differences in communication sub-systems and to provide a uniform view of data transport layer to the systems engineer. We applied this paradigm to the design and implementation of intelligent data servers in the Compact Muon Solenoid (CMS) data acquisition system at CERN to easily exploiting the physical communication resources of the available equipment. CMS is a high-energy physics experiment under study that incorporates a highly distributed data acquisition system. This paper outlines the architecture of one part, the so called Readout Unit, and shows how we can exploit the object advantage for systems with specific data rate requirements. A C++ streams communication layer with zero copying functionality has been established for UDP, TCP, DLPI and specific Myrinet and VME bus communication on the VxWorks real-time operating system. This software provides performance close to the hardware channel and hides communication details from the application programmers. (28 refs)