Lightweight Preservation EnvironmentGary Jackson <garyj@umiacs.umd.edu>

Introduction

The LPE is a prototype data grid built in conjunction with Fujitsu Labs of America

In part, the LPE is a test bed for exercising Globus grid technologies

An intention of the LPE is to preserve data. I will not be talking about the preservation measures today.

Globus Components

The LPE is largely built on Globus Toolkit componentsGrid Security Infrastructure (GSI) and GSI

interfacesReplica Location Service (RLS)Metadata Catalog Service (MCS)GridFTP

Implementation

The implementation is based on GT3 and the Open Grid Services Infrastructure (OGSI)

This infrastructure is being replaced with Web Services Resource Framework (WS-RF)

Implementation

The LPE is implemented as a set of Grid Services

This means each component has it’s own API that can be accessed through web-service remote procedure call

Implementation

The Data Manager (DM) is the core of the LPE

The Preservation Manager (PM) and Transform Manager (TM) handle preservation aspects

The interface is servlet-based to talk natively to the DM

Lessons Learned

Globus is flexible, but also complicated Some Globus components are fragile

(MCS, RFT) while others are very solid and reliable (GSI interfaces, GridFTP)

Globus is evolving and improving: the implementation was made much better with subsequent toolkit releases