File retention
Halo offers a configurable file retention policy that allows users to specify the duration after which original files, protected files and analysis reports will be automatically removed from internal storage. The retention behavior varies depending on how files are submitted to Halo.
Cleanup service
The Halo cleanup service is responsible for the automatic deletion of files from internal storage. It accomplishes this through two methods. Firstly, the services will notify cleanup to remove files once they are no longer required. Secondly, a scheduled Cron Job is executed periodically to remove any extraneous files from storage.
The Cron Job can be configured to modify the quantity of files that are cleaned up, the maximum age for files stored, and the schedule in which it is executed.
For more information on configuration of the Cleanup Service please refer to Configuration Changes.
Retention by submission method
Sync API
Files submitted via the Sync API are removed from internal storage immediately after the response is returned to the caller. The cleanup service cron job acts as a safety net to remove any orphaned files that were not cleaned up during processing.
Async API
Due to the asynchronous nature of the API, files are retained for a configurable period to allow users time to retrieve results. This retention window can be configured through the QUEUE__MessageDelayInMs setting of the Async API (default: 1 hour). After this period, the cleanup service removes the files. The cron job maxAge setting provides an additional safety net for any files that were not cleaned up by the message-based mechanism. Ensure maxAge is greater than or equal to QUEUE__MessageDelayInMs.
For more information on configuration of the Async API please see Async API Configuration.
ICAP (Internet Content Adaptation Protocol)
The ICAP server forwards files to the Sync API for protection. The Sync API retention behavior described above applies to these files. The ICAP server maintains its own local cache of protected files, which is governed by a cache size limit rather than a time-based retention policy.
Storage Monitor
Storage Monitor protects files in place within the connected cloud storage (e.g. OneDrive, SharePoint, Outlook). Files are removed from Halo's internal storage immediately after Storage Monitor replaces the original file in cloud storage. The Halo file retention policy does not apply to files in the customer's cloud storage - retention of those files is governed by the customer's own cloud storage policies.
Portal
The Portal's "Clean a File" feature submits files to the Sync API for protection. The Sync API retention behavior described above applies - files are removed from internal storage immediately after the response is returned.