Alberto Santoro

JavaFIRE: A Replica and File System for Grids

The work is focused on the creation of a replica and file transfers system for Computational Grids inspired on the needs of the High Energy Physics (HEP). Due to the high volume of data created by the HEP experiments, an efficient file and dataset replica system may play an important role on the computing model. Data replica systems allow the creation of copies, distributed between the different storage elements on the Grid. In the HEP context, the data files are basically immutable. This eases the task of the replica system, because given sufficient local storage resources any dataset just needs to be replicated to a particular site once. Concurrent with the advent of computational Grids, another important theme in the distributed systems area that has also seen some significant interest is that of peer-to-peer networks (p2p). P2p networks are an important and evolving mechanism that eases the use of distributed computing and storage resources by end users. One common technique to achieve faster file download from possibly overloaded storage elements over congested networks is to split the files into smaller pieces. This way, each piece can be transferred from a different replica, in parallel or not, optimizing the moments when the network conditions are better suited to the transfer. The main tasks achieved by the system are: the creation of replicas, the development of a system for replicas transfer (RFT) and for replicas location (RLS) with a different architecture that the one provided by Globus and the development of a system for file transfer in pieces on computational grids with interfaces for several storage elements. The RLS uses a p2p overlay based on the Kademlia algorithm.

New Challenges for Computing in High Energy Physics

In view of the new scientific programs established for the LHC (Large Hadron Collider) era, the way to face the technological challenges in computing was develop a new concept of GRID [1, 2] computing. We show some examples and, in particular, a proposal for high energy physicists in countries like Brazil. Due to the big amount of data and the need of close collaboration it will be impossible to work in research centers and universities very far from Fermilab or CERN unless a GRID architecture is built. An important effort is being made by the international community to up to date their computing infrastructure and networks.

Diffractive Production of

We show that the cross section of the diffractive production of

b \bar b

b\overline{b}