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.

Re-Importing Tokens

Occasionally we need to re-import tokens in order to keep consistency among the network about what is being validated. This can be done either through the API or through the web UI, and this example will be going through the UI.

1. Transfer the token store for your collection on to a local workstation (this is needed for the file upload)
   1. Tokens are transferred alongside the collection, so they should be on the same filesystem your replication client pulls into. 
   2. Within chronopolis, the token store is normally suffixed with the date it was written, so for the collection figshare_1074_productionfiles_2019-05-22-10-53-00 the token store will be figshare_1074_productionfiles_2019-05-22-10-53-00_2019-06-06
2. Select your collection in the ACE AM interface and using the more... drop down menu, select Import Tokens

3. Using the Browse form option, navigate to the token store which you transferred to your local workstation and upload it to the ACE Audit Manager
4. Status of the Token Import can be tracked in a few ways
   1. The Import Tokens servlet should direct to a TokenImportStatus page, showing which tokens are processing
   2. The aceam.log will display a line when a token is imported
   3. The Event Log will receive new entries titled TOKEN_INGEST_UPDATE which will all be linked to the session which is importing the Tokens

Database Dump

Directions for dumping the ACE Database

For example at UCSD, aceServer is the ACE database server, aceUser is the DB account, and aceDB is the ACE database

mysqldump -h aceServer -u aceUser aceDB -p > ucsd-ace-2019-06-21.sql
gzip ucsd-ace-2019-06-21.sql

Upload to chron-ingest

Assumes the current user has an SSH public key in the chronopolis user authorized_keys for incoming

scp ucsd-ace-2019-06-21.sql.gz chronopolis@chron-ingest.ucsd.edu:.

At his point the ACE Database dump is at UCSD and can be deposited into chronopolis