In order to provide bit level preservation, we use the Audit Control Environment to run periodic fixity checks on Bags stored in Chronopolis. The ACE Audit Managear webapp gives us two levels of verification when doing our checks: the first is that the file is valid, and the second is that the digest for the file is valid.
When distributing a Bag throughout the Chronopolis network, ACE Tokens are generated and distributed alongside the Bag so that we have a single source for the ACE Tokens. The ACE Tokens are loaded before the initial audit of a Bag which provides us assurance that the digests for each file are correct, as any file which generates an incorrect fixity will be flagged as corrupt through the Token validation.
In addition, there is timestamp information stored in the ACE Tokens which serves as a piece of provenance for when a file was first validated by Chronopolis.
Links
- Gitlab: https://gitlab.umiacs.umd.edu/adapt/ace
- Builds: http://adaptci01.umiacs.umd.edu/resource/ace
- API: https://ace-docs.umiacs.io/
Installation
Installation instructions are available on the ACE Wiki
Administration
Adding A Collection
Removing A Collection
When viewing a collection, select the Remove Collection option from the drop down list of available actions. You will be prompted to acknowledge the delete, after which all files, tokens, and logging events will be removed from ACE.
On larger collections it can take time for all the monitored information to be removed, but ACE can still be browsed during this time.
Creating Peer User
Creating a new user is done through the Accounts servlet which is available from the top most navigation bar in ACE AM. Supplying an account with the following properties allows a peer to log in and provide any comparison operations without allowing them to make changes to your local ACE.
Adding A Peer
Adding a site is done through the /PartnerSite page. Currently no link is available on the main ACE page - only through editing a collection's settings: Add Peers -> Add New or the Compare Collection -> Add New under Partner
Peer Auditing
In order to initiate an on demand peer comparison, the Compare Collection option must be selected when viewing a collection. Then, selecting the Partner option will bring up a list of all peer ACE AMs, which can be selected. ACE will try to find the matching collection by default, but if it is not found you must select the collection to compare to your self.
Database Dump
Directions for dumping the ACE Database
