The LCG POOL Project, General Overview and Project Structure

TL;DR

The POOL project develops a hybrid, component-based persistency framework for the LHC Computing Grid, enabling distributed storage of large experiment data using C++ object streaming and relational databases.

Contribution

It introduces a novel hybrid approach combining ROOT I/O and relational databases within a component-based architecture for grid data persistency.

Findings

Framework supports multi-Petabyte distributed data storage

Combines C++ object streaming with relational databases

Provides navigational access without exposing storage details

Abstract

The POOL project has been created to implement a common persistency framework for the LHC Computing Grid (LCG) application area. POOL is tasked to store experiment data and meta data in the multi Petabyte area in a distributed and grid enabled way. First production use of new framework is expected for summer 2003. The project follows a hybrid approach combining C++ Object streaming technology such as ROOT I/O for the bulk data with a transactionally safe relational database (RDBMS) store such as MySQL. POOL is based a strict component approach - as laid down in the LCG persistency and blue print RTAG documents - providing navigational access to distributed data without exposing details of the particular storage technology. This contribution describes the project breakdown into work packages, the high level interaction between the main pool components and summarizes current status and plans.