Table of Contents

Service Orchestration: LSO script configuration

Tip

An example LSO script is available as part of the framework: SRM_LSOTemplate.

LSO scripts are responsible for orchestrating the configuration of resources, i.e. launching Profile-Load Scripts to configure the resources included in bookings. See Life cycle Service Orchestration (LSO) script.

When an event needs to be triggered (e.g. end of pre-roll) for a specific booking, the SRM framework will look up the target service state defined in the Booking Manager app (e.g. START). Based on this, it will then identify the LSO script to run by looking at the list of actions defined in the service definition.

Main classes

LSO scripts can make use of the following classes to interact with bookings and their included resources:

  • LsoEnhancedAction: Used to retrieve information about the event or the target service state triggering the LSO script.
  • SrmBookingConfiguration: Used to interact with the booking and related objects (e.g. get a list of resources).
  • SrmResourceConfiguration: Used to interact with the resource/function DVE (e.g. apply a profile).
Tip

Load SLSRMLibrary.dll in a software development environment to get an exhaustive list of the available methods.

LsoEnhancedAction class

With the LsoEnhancedAction class, an LSO script can implement different logic based on:

  • The target service state (start, stop, standby, etc.).

    var enhancedAction = new LsoEnhancedAction(engine.GetScriptParamValue<string>("Action"));
switch (enhancedAction.ServiceState)
{
   case "START":
...
}

  • The event

    var enhancedAction = new LsoEnhancedAction(engine.GetScriptParamValue<string>("Action"));
switch (enhancedAction.Event)
{
   case SrmEvent.START_BOOKING_WITH_PREROLL:
...
}

    You can configure the following events:

    • START_BOOKING_WITH_PREROLL: Event that will happen at the beginning of a booking.
    • START: Event that will happen when the pre-roll stage ends. If there is no pre-roll stage, the event will run right after the START_BOOKING_WITH_PREROLL event.
    • STOP: Event that will happen when the post-roll stage starts. If there is no post-roll stage, the event will run at the booking end time.
    • STOP_BOOKING_WITH_POSTROLL: Event that will happen at the end of the booking. If there is no post-roll stage, the event will run right after the STOP event.

SrmBookingConfiguration class

In LSO scripts, you can use the SrmBookingConfiguration class to interact with the resources part of the booking. You can do so by:

  • Using the label of the node in the service definition. For example, if the node has the "Decoder" label:

    var decoderResource = SrmBookingConfiguration.GetResource("Decoder");

    This will return an SrmResourceConfiguration object.

  • Retrieving all resources and checking the node label:

    var resources = SrmBookingConfiguration.GetResourcesToOrchestrate().ToArray();

    This will return an array of SrmResourceConfiguration objects. The Label property on the SrmResourcesConfiguration object can then be used to access the node label.

SrmResourceConfiguration class

The SrmResourceConfiguration object allows the use of the following methods to trigger the execution of Profile-Load Scripts:

  • SrmResourceConfiguration.ApplyProfile(string profileAction)

    Used on a non-contributing resource. Executes the Profile-Load Script and applies the configuration selected at booking creation time.

  • SrmResourceConfiguration.ApplyServiceActionProfile(string serviceAction, string profileAction)

    Used on a non-contributing resource. Executes the Profile-Load Script and applies the state profile instance associated with the profile instance selected at booking creation time.

  • SrmResourceConfiguration.ApplyContributingState(string serviceState)

    Used in the LSO script associated with a main booking and on a contributing resource.

    Executes:

    • The Profile-Load Script defined on the contributing node of the main service definition (with the ApplyProfileScript property).

    • The LSO script associated with the service definition of the contributing booking, if defined.

  • SrmResourceConfiguration.ApplyContributingProfile()

    Used in the LSO script associated with a main booking and on a contributing resource.

    Executes:

    • The Profile-Load Script defined on the contributing node of the main service definition (with the ApplyProfileScript property), providing the settings specified at booking creation time.

    • The LSO script associated with the service definition of the contributing booking, if defined.

By default, the methods above will launch a Profile-Load Script and validate each set. This means that by default, the performCheckSets flag is set to true. However, overloaded methods exist to launch the script without validating each set:

  • SrmResourceConfiguration.ApplyContributingState(string serviceState, bool performCheckSets)

  • SrmResourceConfiguration.ApplyProfile(string profileAction, bool performCheckSets)

  • SrmResourceConfiguration.ApplyServiceActionProfile(string serviceAction, string profileAction, bool performCheckSets)

When data needs to be returned from the execution of a Profile-Load Script, you can use the following methods:

  • resourceConfig.ApplyContributingStateWithReturn

  • resourceConfig.ApplyServiceActionProfileWithReturn

  • resourceConfig.ApplyProfileWithReturn

These three methods will return a <string,string> dictionary. However, for this to happen, the Profile-Load Script must build the dictionary (see Returning data).

Updating booking parameters

In LSO scripts, you can update profile parameters or profile instances on booking level using the SrmResourceConfigurationSetParameter() or SrmResourceConfigurationSetProfileInstance() methods. For example:

  • resource.SetParameter(TestSystemIds.ProfileParameters.Video_State, "Test Video State", false);

  • resource.SetParameter(TestSystemProfileParameters.Vendor.Name, "VendorB", false);

  • resource.SetParameter(InterfaceType.In, "ASI", TestSystemIds.ProfileParameters.Bitrate, 55, false);

  • resource.SetParameter(1, TestSystemProfileParameters.Active_ASI_Interface.Name, "SDI", false);

  • resource.SetParameter(InterfaceType.In, 1, TestSystemProfileParameters.Active_ASI_Interface_Port.ID, 99, false);

  • resource.SetProfileInstance(TestSystemProfileInstances.Decoding_VendorB.ID, false);

  • resource.SetProfileInstance(TestSystemProfileInstances.ASI_Profile_2.ID, 1, true);

Note

The forceSave boolean should only be set to "true" for the last call, as it will effectively trigger the update of the booking. This way you avoid unnecessary updates of the booking, which would affect performance.

Manipulating unlinked resources

When a booking contains resources that are not linked to any node of the service definition, it is still possible to retrieve them from within an LSO script and trigger their configuration:

// Select all unmapped resources, assigned to the booking
var unmappedResources = srmBookingConfig.GetUnmappedResources();

You can then use the following methods to initiate their configuration:

  • ApplyProfile("APPLY");
  • ApplyServiceActionProfile("START", "APPLY");
  • orchestrationHelper.ApplyCombinedProfile("START", "APPLY");
Note

To retrieve all resources in a booking regardless of whether they are linked to a node in the service definition, you can use the following method:

// Select all mapped and unmapped resources, assigned to the booking
var resources = srmBookingConfig.GetResourcesToOrchestrate();
Tip

See also: Silently applying a profile to an unmapped resource

Handling LSO script failures

In case an LSO script fails and throws an exception or exits with engine.ExitFail, the service state will be set to Failed.

The booking life cycle state will also be adjusted to one of the following values:

  • Failed Service Pre-Roll: If the LSO script failed at the start of a booking, i.e. at the start of the pre-roll stage.

  • Failed Service Active: If the LSO script failed at the end of the pre-roll stage.

  • Failed Service Post-Roll: If the LSO script failed at the start of the post-roll stage.

  • Failed Completed: If the LSO script failed at the end of the post-roll stage.

Future events can detect that a previous event has failed, and they can decide to skip Profile-Load Script execution and keep the booking in a "Failed" service state. This is illustrated in the example LSO script.

var enhancedAction = new LsoEnhancedAction(engine.GetScriptParamValue<string>("Action"));
string previousState = enhancedAction.PreviousServiceState
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