Task Manager

Task chaining

Version:

You can determine the execution order of a set of tasks by passing in a list of prerequisite task IDs when you register each task. In the following example, task #2 and task #3 are registered with an array of prerequisite task IDs.

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Sitecore.Processing.Engine;
using Sitecore.Processing.Engine.Abstractions;
using Sitecore.Processing.Tasks.Options.DataSources.DataExtraction;
using Sitecore.XConnect;

namespace Sitecore.Docs.Examples
{
    public class DocTaskManager
    {
        public async Task Sample()
        {
            TaskManager taskManager = null;

            // Task #1
            Guid distributedTaskId = await taskManager.RegisterDistributedTaskAsync(
                new ContactDataSourceOptionsDictionary(new ContactExpandOptions(new string[] { "TestFacetKey" }), 300, 300),
                new DistributedWorkerOptionsDictionary("Sitecore.Documentation.SampleDistributedWorker", new Dictionary<string, string> { { "testkey", "testvalue" } }),
                null,
                TimeSpan.MaxValue);

            // Task #2
            Guid deferredTaskId = await taskManager.RegisterDeferredTaskAsync(
                new DeferredWorkerOptionsDictionary("Sitecore.Documentation.SampleDeferredWorker",
                new Dictionary<string, string>() { { "testkey", "testvalue" } }),
                new Guid[] { distributedTaskId }, // Will not run before task #1 is complete
                TimeSpan.MaxValue);

            // Task #3
            Guid deferredTaskId = await taskManager.RegisterDeferredTaskAsync(
                new DeferredWorkerOptionsDictionary("Sitecore.Documentation.SecondSampleDeferredWorker",
                new Dictionary<string, string>() { { "testkey", "testvalue" } }),
                new Guid[] { deferredTaskId }, // Will not run before task #2 is complete
                TimeSpan.MaxValue);
        }
    }
}

Chaining projection and merge

When you register a data projection task, you must register a dependent merge task that executes when data projection is complete.

Data projection is performed by a distributed worker (ProjectionWorker). Each worker projects data into its own temporary table in the Cortex Processing Engine Storage database, which means that ten workers will produce ten separate tables. The merge worker (MergeWorker) combines the data into a single table and deletes the temporary tables.

Tip

The RegisterModelTrainingTaskChainAsync() method in the Sitecore.Processing.Engine.Abstractions.TaskManagerExtensions extension class creates a chain of three tasks, including data projection and merge.

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