Dalet Flex Core: Resources

Introduction

Resources are external services that are used by Dalet Flex to store, transfer or process media. Examples include storage devices, transcoder software, and file transfer technologies. Resources extend the core functionality of Dalet Flex and enable it to meet the demands of modern media management operations by utilising commodity technologies.

A core aspect of media logistics involves orchestrating media files between various locations (storage) and processes (transcode, QC, etc).

Resource Types

Dalet Flex supports 3 high-level resource types. These types are further sub-divided into more specific types.

The high level type defines the general purpose of the resource:

• Capacity Resource: A resource that is used for storing media files such as a network mounted storage array, or cloud-based object storage.
• Processing Resource: A resource that is used for processing media such as transcoders.
• I/O Resource: A resource that is used for moving media files such as file delivery technologies.

The resource types available are described in the Resource Plugins section of this article.

Pluggable approach to resource management

Dalet Flex offers a pluggable approach to resource management so that new resource types and vendor solutions can be added over time by developing new resource plugins. Dalet Flex already plugs into the industry leading, storage, transcode and QC solutions. This approach means that Dalet Flex offers a high degree of futureproofing as new networked media management technologies evolve. For example, Dalet Flex can offer plugins for traditional network file storage or internet-based object storage.

Dalet Flex resources can manage one or more items on behalf of Dalet Flex and the exact item type is governed by the resource type, for example a Capacity resource manages file items.

Resources and Jobs 

Dalet Flex jobs rely on resources to get work done. For example, transcode jobs delegate the work of transcoding a file to a transcode resource. Like all Dalet Flex objects, resources support the concept of visibility. When a job runs, it runs with an owner that is a Dalet Flex user. Resources are only made available to jobs that have visibility for the resource. This means that resources can be shared between accounts where necessary but can also be isolated to individual accounts.

Resource Management

Dalet Flex maintains a snapshot of the status of all resources and their associated items. Resources can exist in different states:

• Stopped: The resource is configured and enabled but stopped. It is not available to process job requests.
• Started: The resource is configured and enabled and started. It is available to process job requests.
• Failed: The resource is configured and enabled but failed. It is not available to process job requests.

The Resource Summary table in the Resources tab displays the status of the Resources in the Dalet Flex environment. You can see an overall summary of the resource status, resource items, storage usage etc in the system. You can link to a specific Resource definition from the Resource Summary screen.

If Dalet Flex cannot obtain a valid response from a resource, or the resource indicates that it has failed, Dalet Flex sets the resource to a Failed state. At this point, the resource cannot handle any future requests. Once a resource has failed it must be restarted. In most cases restart is performed manually, but certain resources can be automatically restarted by the system. For example, hotfolder service automatically tries to restart failed hotfolders at fixed time intervals. If during this scheduled task, the hotfolder service finds an error that needs manual intervention to fix, it will internally disable the hotfolder resource. Failed Folder resources can be automatically restarted a configurable number of times before they are failed in a way that requires manual intervention.

Resource Items

A resource item is an object that represents a file currently referenced on a Capacity Resource. The resource item object contains information about the file, its size, when it was created, and the last time it was modified; like all objects in Flex, an ID is assigned to each resource item. In Flex workflows, the variable resourceItemName is used to reference the file represented by the resource item.  

You can see the details of the Resource Items in a particular Capacity Resource in the Resource Summary screen. In a Capacity Resource, the Resource Item consistency with file storage status is maintained on an Event basis, so when Actions are executed (e.g.: import, copy, move, purge etc) the Resource Items snapshot is updated.

Click on any of the values in the Items column to see the Resource Items in that resource.

You can also click  on the Resource Items link in the Resource Definition to see the associated Resource Items .

Resource items are the mechanism used by a Hot Folder/Inbox to pass details of the detected file to workflows. For example, when a workflow is triggered by a Hot Folder, a workflow variable called resourceItemName (along with some other variables) is set containing the name of the resource item. This can then be used by the workflow to perform various actions on the file represented by the resource item. (e.g. Import and move the file to another Storage Resource). 

Creating a New Resource

1. Access Flex Core.

2. On the toolbar, click New and select Resource from the drop-down menu.

3. In the Create new Resource section, complete the following fields:

• Name: Enter a name for your resource definition
• Description: Enter a description for your resource definition (optional)
• Visibility: Select an account that has visibility of your resource definition
• Plugin: Select a plugin from the drop-down menu
• Polling Interval: select an interval from the drop-down menu (optional)
• Run-Rule Expression: enter a run rule expression (optional) - only available for process resources

4. Click Save to create the Resource.

Run-Rules for Process Resources

Process resources, such as package, inject, quality control, and extract resources support the use of run-rule expressions. Add a run-rule in the Create a new Resource… section to evaluate whether a resource is available to perform an action or not. For example, you could use this run rule to use one process resource to transcode assets with Variant=Video. 

#{object.type.name == "media-asset" && object.variant.name == "Video"}

NOTE: The Run-Rule Expression text box is only visible when a process resource is selected.

Resource Plugins

Once you have created your Resource, select the Configuration sub-tab to define the values that you wish to assign to your new resource. Each Plugin requires different configuration parameters.

These are the Resource plugins available in Dalet Flex. Click the links to see more information about the specific configuration required for each Resource plugin