We describe the deployment of the Audit Control Environment (ACE) on the Chronopolis distributed archive environment. The ACE system provides a scalable, auditable platform to actively ensure the availability and integrity of digital archival holdings over the lifetime of the archive. The core of ACE is a small integrity token issued for each monitored item that is part of a larger, externally auditable cryptographic system. Two components that describe this system, the Audit Manager and Integrity Management Service, have been developed and were released in October 2008.ACE allows for the policy driven active monitoring of collections on a variety of disk and grid based storage systems. Each collection in ACE is subject to monitoring based on a customizable policy.The Chronopolis archiving environment consists of three sites located at the University of Maryland(UMD), San Diego Supercomputing Center(SDSC)/UCSD Libraries, and the National Center for Atmospheric Research(NCAR). Data that has been ingested into storage at SDSC is replicated to UMD and NCAR. Current collections from data providers in Chronopolis range from a relatively few large files to collections containing millions of mostly small files. In total, these collections represent over 5.5 million files and 17 Terabytes of data.With three copies of each object, the problem of ensuring the integrity of each copy across the three sites arises. An ACE Audit Manager at each site provides continuous monitoring of files to ensure no corruption occurs locally. In addition, periodic audits of each collection across the sites are made to ensure that the collection contents are consistent across all three sites.We describe the deployment and performance of the Audit Manager at each of the three sites. Specifically, we compare peak theoretical ACE performance against varying collections.
Michael Smorul, Joesph JaJa, "A Case Study in Distributed Collection Monitoring and Auditing Using the Audit Control Environment (ACE)" in Proc. IS&T Archiving 2009, 2009, pp 183 - 186, https://doi.org/10.2352/issn.2168-3204.2009.6.1.art00039