DIRAC - Distributed Infrastructure with Remote Agent Control

TL;DR

DIRAC is a distributed system for LHCb Monte Carlo production that uses a client/server architecture with software agents for job management, successfully deployed across multiple institutes and adaptable to various grid environments.

Contribution

The paper introduces DIRAC, a flexible, agent-based distributed infrastructure for high-energy physics data processing, capable of operating across diverse grid middleware environments.

Findings

Successfully installed at 18 institutes

Used in recent Physics Data Challenges

Supports mixed grid environments

Abstract

This paper describes DIRAC, the LHCb Monte Carlo production system. DIRAC has a client/server architecture based on: Compute elements distributed among the collaborating institutes; Databases for production management, bookkeeping (the metadata catalogue) and software configuration; Monitoring and cataloguing services for updating and accessing the databases. Locally installed software agents implemented in Python monitor the local batch queue, interrogate the production database for any outstanding production requests using the XML-RPC protocol and initiate the job submission. The agent checks and, if necessary, installs any required software automatically. After the job has processed the events, the agent transfers the output data and updates the metadata catalogue. DIRAC has been successfully installed at 18 collaborating institutes, including the DataGRID, and has been used in recent Physics Data Challenges. In the near to medium term future we must use a mixed environment with different types of grid middleware or no middleware. We describe how this flexibility has been achieved and how ubiquitously available grid middleware would improve DIRAC.