Delayed deletion plugin (new in Orthanc 1.11.1)

This page describes the official sample plugin that performs delayed deletions of storage files.

On some file systems, the deletion of files can be quite long and therefore, a DELETE request on a study with thousands of instances can last minutes.

The Delayed deletion plugin handles file deletion asynchronously by pushing the files to delete into a queue that is handled asynchronously. This queue is stored in a SQLite DB stored on disk which allows the plugin to resume deletions if Orthanc is stopped/restarted while deleting files.

Configuration

Here’s a sample configuration section for this plugin with its default values:

{
  "DelayedDeletion": {

    // Enables/disables the plugin
    "Enable": false,

    // Delay (in milliseconds) between deletion of 2 files
    // This avoids overloading Orthanc disk with the deletion
    // of files and leaves room for other operations.
    // '0' means no throttling.
    "ThrottleDelayMs": 0,

    // Force the path of the SQLite DB
    // By default, this value is generated by the plugin base on
    // the "StorageDirectory" and "DatabaseServerIdentifier"
    // configurations.
    // If running multiple Orthanc on the same storage, make
    // sure that they use different "Path" for the DelayedDeletion DB
    // "Path": "/my/path/delayed-deletion.db"
  }
}

Working with multiple Orthanc instances

When running multiple instance on the same DB (e.g a PostgreSQL DB), each Delayed Deletion plugin will maintain its own list of files to delete and store it in its own SQLite DB. To make sure each instance has its own DB, the plugin uses the DatabaseServerIdentifier configuration to generate the name of the SQLite DB.

Status

You can get a progress status of the plugin by calling the /delayed-deletion/status API route.

Compilation

This plugin is part of the Orthanc core repository and is included in the Orthanc makefile. It is compiled with Orthanc itself and is distributed together with Orthanc binaries.