The PROOF Distributed Parallel Analysis Framework based on ROOT

The development of the Parallel ROOT Facility, PROOF, enables a physicist to analyze and understand much larger data sets on a shorter time scale. It makes use of the inherent parallelism in event data and implements an architecture that optimizes I/O and CPU utilization in heterogeneous clusters with distributed storage. The system provides transparent and interactive access to gigabytes today. Being part of the ROOT framework PROOF inherits the benefits of a performant object storage system and a wealth of statistical and visualization tools. This paper describes the key principles of the PROOF architecture and the implementation of the system. We will illustrate its features using a simple example and present measurements of the scalability of the system. Finally we will discuss how PROOF can be interfaced and make use of the different Grid solutions.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, CA, USA, March 2003, 5 pages, LaTeX, 4 eps figures. PSN TULT00

Achieving scalability in hierarchical location services

Services for locating mobile objects are often organized as a distributed search tree. A potential problem with this organization is that high-level nodes may become a bottleneck, affecting the scalability of the service. A traditional approach to handle such problems is to also distribute the location information managed by a single node across multiple machines

Development of a radiation hard version of the Analog Pipeline Chip APC128

The Analog Pipeline Chip (APC) is a low noise, low power readout chip for silicon micro strip detectors with 128 channels containing an analog pipeline of 32 buffers depth. The chip has been designed for operation at HERA with a power dissipation of 300-400 muW per channel and has been used also in several other particle physics experiments. In this paper we describe the development of a radiation hard version of this chip that will be used in the H1 vertex detector for operation at the luminosity upgraded HERA machine. A 128 channel prototyping chip with several amplifier variations has been designed in the radiation hard DMILL technology and measured. The results of various parameter variations are presented in this paper. Based on this, the design choice for the final production version of the APC128-DMILL has been made.Comment: 10 pages, 10 figure

Exploiting Location Awareness for Scalable Location-Independent Object IDs

We are building a wide-area location service that tracks the current location of mobile and replicated objects. The location service should support up to 10 12 objects on a worldwide scale. To support this huge number of objects, the workload of the location service is distributed over multiple hosts. Our load distribution method is unique in that it is aware of the (geographical) location of the hosts it uses. By using this location knowledge when distributing the workload, the distribution mechanism enforces locality of operations in the location service. Enforcing locality minimizes the use of global network resources by the location service and thereby enhances its scalability. We also show how this location-aware load distribution mechanism can be implemented. 1 Introduction Objects provide an easy way to model both applications and system services. It is therefore easy to understand that the use of objects as a design and implementation method has become popular, for example..

Scheduling concurrent rpcs in the globe location service

Globe is a wide-area distributed system in which an object can be located through its location-independent identifier. This is done by means of a worldwide location service. In contrast to comparable services, the approach that is followed in Globe allows objects to be highly mobile, replicated, or physically distributed. In addition, our algorithms adapt dynamically to an object’s behavior, resulting in an efficient and above all, scalable approach. The algorithms for updating and looking up an object’s location are expressed as high-level operations on a worldwide search tree. We have designed and implemented a middleware layer providing all the necessary network communication. In this paper, we show that such a layer hardly introduces any additional overhead. The important consequence is that our location service can be designed and implemented at a high level of abstraction. Compared to the design and implementation of comparable worldwide services, this approach is quite unique