VENDITE: 1-800-867-1389

Implementazione di uno scenario di flusso con failover

Aggiornamento: agosto 2014

In questo scenario viene illustrato come copiare il contenuto (BLOB) da un asset in un altro per gestire la ridondanza per la trasmissione in flusso su richiesta. È utile per i clienti che desiderano configurare la propria rete CDN (Content Delivery Network) per il failover tra due centri dati, nel caso in cui in uno di questi si verifichi un'interruzione.

Questo scenario usa Servizi multimediali di Microsoft Azure SDK, l'API REST di Servizi multimediali di Microsoft Azure e Azure Storage SDK per illustrare le seguenti attività.

  1. Impostazione di un account Servizi multimediali nel "Centro dati A".

  2. Caricamento di un file in formato intermedio in un asset di origine.

  3. Codifica dell'asset in file MP4 a più velocità in bit.

  4. Creazione di un localizzatore SAS di sola lettura per l'asset di origine affinché disponga di accesso in lettura al contenitore nell'account di Storage a esso associato.

  5. Recupero del nome del contenitore dell'asset di origine dal localizzatore SAS di sola lettura creato nel passaggio precedente. Questa informazione è necessaria per eseguire la copia dei BLOB tra gli account di archiviazione. L'operazione di copia è descritta più avanti in questo argomento.

  6. Creazione di un localizzatore di origine per l'asset creato mediante l'attività di codifica.



    Quindi, per gestire il failover:



  7. Impostazione di un account Servizi multimediali nel "Centro dati B".

  8. Creazione di un asset di destinazione vuoto nell'account di Servizi multimediali.

  9. Creazione di un localizzatore SAS di sola lettura per l'asset di origine affinché disponga di accesso in lettura al contenitore nell'account di Storage di destinazione a esso associato.

  10. Usare Azure Storage SDK per copiare i BLOB (file degli asset) dall'account di archiviazione di origine del "Centro dati A" in quello di destinazione nel "Centro dati B" (questi account di archiviazione sono associati agli asset di interesse).

  11. Associare i BLOB (file degli asset) copiati nel contenitore dei BLOB di destinazione agli asset di destinazione.

  12. Creare un localizzatore di origine per l'asset nel "Centro dati B" e specificare l'Id del localizzatore generato per l'asset nel "Centro dati A".

    Questa operazione consente di ottenere gli URL del flusso i cui percorsi relativi sono identici (solo gli URL di base sono differenti).

  13. Quindi, per gestire qualsiasi interruzione, è possibile creare una rete CDN basata su questi localizzatori di origine.

Sono valide le seguenti considerazioni:

  • La versione corrente di Servizi multimediali SDK non supporta la creazione di un localizzatore con un ID specificato. Per completare questa attività, verrà usata l'API REST di Servizi multimediali.

  • La versione corrente di Servizi multimediali SDK non supporta la generazione dell'informazione IAssetFile a livello di programmazione che deve associare un asset ai file di asset. Per completare questa attività, verrà usata l'API REST CreateFileInfos di Servizi multimediali.

  • Gli asset crittografati nell'archiviazione (AssetCreationOptions.StorageEncrypted) non sono supportati per la replica, in quanto la chiave di crittografia presente in entrambi gli account di Servizi multimediali sarà differente.

  • Per sfruttare i vantaggi della creazione dinamica dei pacchetti, è prima necessario ottenere almeno un'unità riservata di trasmissione in flusso su richiesta. Per altre informazioni, vedere Walkthrough: Dynamically Packaging Assets.

TipSuggerimento
Valutare la possibilità di usare lo strumento per la replica di Servizi multimediali come alternativa all'implementazione manuale di uno scenario di flusso con failover. Questo strumento consente di eseguire la replica di asset in due account di Servizi multimediali.

  • Due account di Servizi multimediali ottenuti con una sottoscrizione di Azure nuova o esistente. Vedere l'argomento relativo alla creazione di un account di Servizi multimediali.

  • Sistemi operativi: Windows 7, Windows 2008 R2 o Windows 8.

  • .NET Framework 4.5 o .NET Framework 4.

  • Visual Studio 2012 o Visual Studio 2010 SP1 (Professional, Premium, Ultimate o Express).

In questa sezione verrà creato e configurato un progetto di applicazione console in C#.

  1. Usare Visual Studio 2012 o Visual Studio 2010 SP1 per creare una nuova soluzione contenente il progetto di applicazione console in C#. Immettere HandleRedundancyForOnDemandStreaming per il nome, quindi fare clic su OK.

  2. Creare la cartella SupportFiles allo stesso livello del file di progetto HandleRedundancyForOnDemandStreaming.csproj. Nella cartella SupportFiles creare le cartelle OutputFiles e MP4Files. Copiare un file con estensione mp4 nella cartella MP4Files (in questo esempio viene usato il file BigBuckBunny.mp4).

  3. Usare Nuget per aggiungere riferimenti alle DLL correlate a Servizi multimediali. Scegliere STRUMENTI -> Gestione pacchetti libreria -> Console di Gestione pacchetti dal menu principale di Visual Studio. Nella finestra della console immettere Install-Package windowsazure.mediaservices e premere INVIO.

  4. Aggiungere altri riferimenti richiesti per il progetto: System.Configuration, System.Runtime.Serialization e System.Web.

  5. Sostituire le istruzioni using aggiunte per impostazione predefinita al file Programs.cs con le seguenti:

    using System;
    using System.Configuration;
    using System.Globalization;
    using System.IO;
    using System.Net;
    using System.Runtime.Serialization.Json;
    using System.Text;
    using System.Threading;
    using System.Threading.Tasks;
    using System.Web;
    using System.Xml;
    using System.Linq;
    using Microsoft.WindowsAzure;
    using Microsoft.WindowsAzure.MediaServices.Client;
    using Microsoft.WindowsAzure.Storage;
    using Microsoft.WindowsAzure.Storage.Blob;
    using Microsoft.WindowsAzure.Storage.Auth;
    
    
  6. Aggiungere la sezione appSettings al file config e aggiornare i valori in base alla chiave di Servizi multimediali e di archiviazione, nonché i valori dei nomi.

    <appSettings>
      <add key="MediaServicesAccountNameSource" value="Media-Services-Account-Name-Source"/>
      <add key="MediaServicesAccountKeySource" value="Media-Services-Account-Key-Source"/>
      <add key="MediaServicesStorageAccountNameSource" value="Media-Services-Storage-Account-Name-Source"/>
      <add key="MediaServicesStorageAccountKeySource" value="Media-Services-Storage-Account-Key-Source"/>
      <add key="MediaServicesAccountNameTarget" value="Media-Services-Account-Name-Target" />
      <add key="MediaServicesAccountKeyTarget" value=" Media-Services-Account-Key-Target" />
      <add key="MediaServicesStorageAccountNameTarget" value=" Media-Services-Storage-Account-Name-Target" />
      <add key="MediaServicesStorageAccountKeyTarget" value=" Media-Services-Storage-Account-Key-Target" />
    </appSettings>
    
    

  1. Aggiungere i seguenti campi a livello di classe alla classe Program.

    // Read values from the App.config file.
    private static readonly string MediaServicesAccountNameSource = ConfigurationManager.AppSettings["MediaServicesAccountNameSource"];
    private static readonly string MediaServicesAccountKeySource = ConfigurationManager.AppSettings["MediaServicesAccountKeySource"];
    private static readonly string StorageNameSource = ConfigurationManager.AppSettings["MediaServicesStorageAccountNameSource"];
    private static readonly string StorageKeySource = ConfigurationManager.AppSettings["MediaServicesStorageAccountKeySource"];
    
    private static readonly string MediaServicesAccountNameTarget = ConfigurationManager.AppSettings["MediaServicesAccountNameTarget"];
    private static readonly string MediaServicesAccountKeyTarget = ConfigurationManager.AppSettings["MediaServicesAccountKeyTarget"];
    private static readonly string StorageNameTarget = ConfigurationManager.AppSettings["MediaServicesStorageAccountNameTarget"];
    private static readonly string StorageKeyTarget = ConfigurationManager.AppSettings["MediaServicesStorageAccountKeyTarget"];
    
    // Base support files path.  Update this field to point to the base path  
    // for the local support files folder that you create. 
    private static readonly string SupportFiles = Path.GetFullPath(@"../..\SupportFiles");
    
    // Paths to support files (within the above base path). 
    private static readonly string SingleInputMp4Path = Path.GetFullPath(SupportFiles + @"\MP4Files\BigBuckBunny.mp4");
    private static readonly string OutputFilesFolder = Path.GetFullPath(SupportFiles + @"\OutputFiles");
    
    // Class-level field used to keep a reference to the service context.
    static private CloudMediaContext _contextSource = null;
    static private CloudMediaContext _contextTarget = null;
    static private MediaServicesCredentials _cachedCredentialsSource = null;
    static private MediaServicesCredentials _cachedCredentialsTarget = null;
    
  2. Sostituire la definizione predefinita del metodo Main con la seguente:

    static void Main(string[] args)
    {
        _cachedCredentialsSource = new MediaServicesCredentials(
                        MediaServicesAccountNameSource,
                        MediaServicesAccountKeySource);
    
        _cachedCredentialsTarget = new MediaServicesCredentials(
                        MediaServicesAccountNameTarget,
                        MediaServicesAccountKeyTarget);
    
        // Get server context.    
        _contextSource = new CloudMediaContext(_cachedCredentialsSource);
        _contextTarget = new CloudMediaContext(_cachedCredentialsTarget);
    
    
        IAsset assetSingleFile = CreateAssetAndUploadSingleFile(_contextSource,
                                    AssetCreationOptions.None,
                                    SingleInputMp4Path);
    
        IJob job = CreateEncodingJob(_contextSource, assetSingleFile);
    
        if (job.State != JobState.Error)
        {
            IAsset sourceOutputAsset = job.OutputMediaAssets[0];
            // Get the locator for Smooth Streaming
            var sourceOriginLocator = GetStreamingOriginLocator(_contextSource, sourceOutputAsset);
    
            Console.WriteLine("Locator Id: {0}", sourceOriginLocator.Id);
    
    
            // 1.Create a read-only SAS locator for the source asset to have read access to the container in the source Storage account (associated with the source Media Services account)
            var readSasLocator = GetSasReadLocator(_contextSource, sourceOutputAsset);
    
    
            // 2.Get the container name of the source asset from the read-only SAS locator created in the previous step
            string containerName = (new Uri(readSasLocator.Path)).Segments[1];
    
    
            // 3.Create a target empty asset in the target Media Services account
            var targetAsset = CreateTargetEmptyAsset(_contextTarget, containerName);
    
            // 4.Create a write SAS locator for the target empty asset to have write access to the container in the target Storage account (associated with the target Media Services account)
            ILocator writeSasLocator = CreateSasWriteLocator(_contextTarget, targetAsset);
    
            // Get asset container name.
            string targetContainerName = (new Uri(writeSasLocator.Path)).Segments[1];
    
    
            // 5.Copy the blobs in the source container (source asset) to the target container (target empty asset)
            CopyBlobsFromDifferentStorage(containerName, targetContainerName, StorageNameSource, StorageKeySource, StorageNameTarget, StorageKeyTarget);
    
    
            // 6.Use the CreateFileInfos Media Services REST API to automatically generate all the IAssetFile’s for the target asset. 
            //      This API call is not supported in the current Media Services SDK for .NET. 
            CreateFileInfosForAssetWithRest(_contextTarget, targetAsset, MediaServicesAccountNameTarget, MediaServicesAccountKeyTarget);
    
            // Check if the AssetFiles are now  associated with the asset.
            Console.WriteLine("Asset files assocated with the {0} asset:", targetAsset.Name);
            foreach (var af in targetAsset.AssetFiles)
            {
                Console.WriteLine(af.Name);
            }
    
            // 7.Copy the Origin locator of the source asset to the target asset by using the same Id
            var replicatedLocatorPath = CreateOriginLocatorWithRest(_contextTarget,
                        MediaServicesAccountNameTarget, MediaServicesAccountKeyTarget,
                        sourceOriginLocator.Id, targetAsset.Id);
    
            // Create a full URL to the manifest file. Use this for playback
            // in streaming media clients. 
            string originalUrlForClientStreaming = sourceOriginLocator.Path + GetPrimaryFile(sourceOutputAsset).Name + "/manifest";
    
            Console.WriteLine("Original Locator Path: {0}\n", originalUrlForClientStreaming);
    
            string replicatedUrlForClientStreaming = replicatedLocatorPath + GetPrimaryFile(sourceOutputAsset).Name + "/manifest";
    
            Console.WriteLine("Replicated Locator Path: {0}", replicatedUrlForClientStreaming);
    
            readSasLocator.Delete();
            writeSasLocator.Delete();
    }
    
  3. Di seguito sono riportate le definizioni dei metodi chiamati da Main.

    public static IAsset CreateAssetAndUploadSingleFile(CloudMediaContext context,
                                                    AssetCreationOptions assetCreationOptions,
                                                    string singleFilePath)
    {
        // For the AssetCreationOptions you can specify 
        // encryption options.
        //      None:  no encryption. By default, storage encryption is used. If you want to 
        //        create an unencrypted asset, you must set this option.
        //      StorageEncrypted:  storage encryption. Encrypts a clear input file 
        //        before it is uploaded to Azure storage. This is the default if not specified
        //      CommonEncryptionProtected:  for Common Encryption Protected (CENC) files. An 
        //        example is a set of files that are already PlayReady encrypted. 
    
        var assetName = "UploadSingleFile_" + DateTime.UtcNow.ToString();
    
        var asset = context.Assets.Create(assetName, assetCreationOptions);
    
        Console.WriteLine("Asset name: " + asset.Name);
    
        var fileName = Path.GetFileName(singleFilePath);
    
        var assetFile = asset.AssetFiles.Create(fileName);
    
        Console.WriteLine("Created assetFile {0}", assetFile.Name);
    
        Console.WriteLine("Upload {0}", assetFile.Name);
    
        assetFile.Upload(singleFilePath);
        Console.WriteLine("Done uploading of {0}", assetFile.Name);
    
        return asset;
    }
    
    public static IJob CreateEncodingJob(CloudMediaContext context, IAsset asset)
    {
        // Declare a new job.
        IJob job = context.Jobs.Create("My encoding job");
    
        // Get a media processor reference, and pass to it the name of the 
        // processor to use for the specific task.
        IMediaProcessor processor = GetLatestMediaProcessorByName(context,
                                                "Windows Azure Media Encoder");
    
        // Create a task with the encoding details, using a string preset.
        // In this case "H264 Adaptive Bitrate MP4 Set 720p" preset is used.
        ITask task = job.Tasks.AddNew("My encoding task",
            processor,
            "H264 Adaptive Bitrate MP4 Set 720p",
            TaskOptions.ProtectedConfiguration);
    
        // Specify the input asset to be encoded.
        task.InputAssets.Add(asset);
    
        // Add an output asset to contain the results of the job. 
        // This output is specified as AssetCreationOptions.None, which 
        // means the output asset is in the clear (unencrypted). 
        var outputAssetName = "OutputAsset_" + Guid.NewGuid();
        task.OutputAssets.AddNew(outputAssetName,
            AssetCreationOptions.None);
    
        // Use the following event handler to check job progress.  
        job.StateChanged += new
                EventHandler<JobStateChangedEventArgs>(StateChanged);
    
        // Launch the job.
        job.Submit();
    
        // Optionally log job details. This displays basic job details
        // to the console and saves them to a JobDetails-{JobId}.txt file 
        // in your output folder.
        LogJobDetails(context, job.Id);
    
        // Check job execution and wait for job to finish. 
        Task progressJobTask = job.GetExecutionProgressTask(CancellationToken.None);
        progressJobTask.Wait();
    
        // Get an updated job reference.
        job = GetJob(context, job.Id);
    
        // Since we the output asset contains a set of Smooth Streaming files,
        // set the .ism file to be the primary file
        if (job.State != JobState.Error)
            SetPrimaryFile(job.OutputMediaAssets[0]);
    
        return job;
    }
    
    // Create a locator URL to a streaming media asset 
    // on an origin server.
    public static ILocator GetStreamingOriginLocator(CloudMediaContext context, IAsset assetToStream)
    {
        // Get a reference to the streaming manifest file from the  
        // collection of files in the asset. 
        IAssetFile manifestFile = GetPrimaryFile(assetToStream);
    
        // Create a 30-day readonly access policy. 
        IAccessPolicy policy = context.AccessPolicies.Create("Streaming policy",
            TimeSpan.FromDays(30),
            AccessPermissions.Read);
    
        // Create a locator to the streaming content on an origin. 
        ILocator originLocator = context.Locators.CreateLocator(LocatorType.OnDemandOrigin,
            assetToStream,
            policy,
            DateTime.UtcNow.AddMinutes(-5));
    
        // Return the locator. 
        return originLocator;
    }
    
    public static ILocator GetSasReadLocator(CloudMediaContext context, IAsset asset)
    {
        IAccessPolicy accessPolicy = context.AccessPolicies.Create("File Download Policy",
            TimeSpan.FromDays(30), AccessPermissions.Read);
    
        ILocator sasLocator = context.Locators.CreateLocator(LocatorType.Sas,
            asset, accessPolicy);
    
        return sasLocator;
    }
    
    public static ILocator CreateSasWriteLocator(CloudMediaContext context, IAsset asset)
    {
    
        IAccessPolicy writePolicy = context.AccessPolicies.Create("Write Policy",
            TimeSpan.FromDays(30), AccessPermissions.Write);
    
        ILocator sasLocator = context.Locators.CreateLocator(LocatorType.Sas,
            asset, writePolicy);
    
        return sasLocator;
    }
    
    public static IAsset CreateTargetEmptyAsset(CloudMediaContext context, string containerName)
    {
        // Create a new asset.
        IAsset assetToBeProcessed = context.Assets.Create(containerName,
            AssetCreationOptions.None);
    
        return assetToBeProcessed;
    }
    
    public static void CreateFileInfosForAssetWithRest(CloudMediaContext context, IAsset asset, string mediaServicesAccountNameTarget,
        string mediaServicesAccountKeyTarget)
    {
        string apiServer = "";
        string scope = "";
        string acsBaseAddress = "";
    
        string acsToken = GetAcsBearerToken(mediaServicesAccountNameTarget,
                                mediaServicesAccountKeyTarget, scope, acsBaseAddress);
    
        if (!string.IsNullOrEmpty(acsToken))
        {
            CreateFileInfos(apiServer, acsToken, asset.Id);
        }
    }
    
    public static string CreateOriginLocatorWithRest(CloudMediaContext context, string mediaServicesAccountNameTarget,
        string mediaServicesAccountKeyTarget, string locatorIdToReplicate, string targetAssetId)
    {
        //Make sure we are not asking for a duplicate:
        var locator = context.Locators.Where(l => l.Id == locatorIdToReplicate).FirstOrDefault();
        if (locator != null)
            return "";
    
        string locatorNewPath = "";
        string apiServer = "";
        string scope = "";
        string acsBaseAddress = "";
    
        string acsToken = GetAcsBearerToken(mediaServicesAccountNameTarget,
                                mediaServicesAccountKeyTarget, scope, acsBaseAddress);
    
        if (!string.IsNullOrEmpty(acsToken))
        {
            var asset = context.Assets.Where(a => a.Id == targetAssetId).FirstOrDefault();
    
            var accessPolicy = context.AccessPolicies.Create("RestTest", TimeSpan.FromDays(100),
                                                                AccessPermissions.Read);
            if (asset != null)
            {
                string redirectedServiceUri = null;
    
                var xmlResponse = CreateLocator(apiServer, out redirectedServiceUri, acsToken,
                                                            asset.Id, accessPolicy.Id,
                                                            (int)LocatorType.OnDemandOrigin,
                                                            DateTime.UtcNow.AddMinutes(-10), locatorIdToReplicate);
    
                Console.WriteLine("Redirected to: " + redirectedServiceUri);
                if (xmlResponse != null)
                {
                    Console.WriteLine(String.Format("Locator Id: {0}",
                                                    xmlResponse.GetElementsByTagName("Id")[0].InnerText));
                    Console.WriteLine(String.Format("Locator Path: {0}",
                            xmlResponse.GetElementsByTagName("Path")[0].InnerText));
    
    
                    locatorNewPath = xmlResponse.GetElementsByTagName("Path")[0].InnerText;
                }
            }
        }
    
        return locatorNewPath;
    }
    
    
    public static void SetPrimaryFile(IAsset asset)
    {
    
        var ismAssetFiles = asset.AssetFiles.ToList().
                    Where(f => f.Name.EndsWith(".ism", StringComparison.OrdinalIgnoreCase))
                    .ToArray();
    
        if (ismAssetFiles.Count() != 1)
            throw new ArgumentException("The asset should have only one, .ism file");
    
        ismAssetFiles.First().IsPrimary = true;
        ismAssetFiles.First().Update();
    }
    
    public static IAssetFile GetPrimaryFile(IAsset asset)
    {
        var theManifest =
                from f in asset.AssetFiles
                where f.Name.EndsWith(".ism")
                select f;
    
        // Cast the reference to a true IAssetFile type. 
        IAssetFile manifestFile = theManifest.First();
    
        return manifestFile;
    }
    
    public static IAsset RefreshAsset(CloudMediaContext context, IAsset asset)
    {
        asset = context.Assets.Where(a => a.Id == asset.Id).FirstOrDefault();
        return asset;
    }
    
    
    public static void CopyBlobsFromDifferentStorage(string sourceContainerName, string targetContainerName,
                                        string srcAccountName, string srcAccountKey,
                                        string destAccountName, string destAccountKey)
    {
        var srcAccount = new CloudStorageAccount(new StorageCredentials(srcAccountName, srcAccountKey), true);
        var destAccount = new CloudStorageAccount(new StorageCredentials(destAccountName, destAccountKey), true);
    
        var cloudBlobClient = srcAccount.CreateCloudBlobClient();
        var targetBlobClient = destAccount.CreateCloudBlobClient();
    
        var sourceContainer = cloudBlobClient.GetContainerReference(sourceContainerName);
        var targetContainer = targetBlobClient.GetContainerReference(targetContainerName);
        targetContainer.CreateIfNotExists();
    
    
        string blobToken = sourceContainer.GetSharedAccessSignature(new SharedAccessBlobPolicy()
        {
            // Specify the expiration time for the signature.
            SharedAccessExpiryTime = DateTime.Now.AddDays(1),
            // Specify the permissions granted by the signature.
            Permissions = SharedAccessBlobPermissions.Write | SharedAccessBlobPermissions.Read
        });
    
    
        foreach (var sourceBlob in sourceContainer.ListBlobs())
        {
            string fileName = (sourceBlob as ICloudBlob).Name;
            var sourceCloudBlob = sourceContainer.GetBlockBlobReference(fileName);
            sourceCloudBlob.FetchAttributes();
    
            if (sourceCloudBlob.Properties.Length > 0)
            {
                var destinationBlob = targetContainer.GetBlockBlobReference(fileName);
                destinationBlob.StartCopyFromBlob(new Uri(sourceBlob.Uri.AbsoluteUri + blobToken));
    
                while (true)
                {
                    // The StartCopyFromBlob is an async operation, 
                    // so we want to check if the copy operation is completed before proceeding. 
                    // To do that, we call FetchAttributes on the blob and check the CopyStatus. 
                    destinationBlob.FetchAttributes();
                    if (destinationBlob.CopyState.Status != CopyStatus.Pending)
                    {
                        break;
                    }
                    //It's still not completed. So wait for some time.
                    System.Threading.Thread.Sleep(1000);
                }
            }
    
            Console.WriteLine(fileName);
        }
    
        Console.WriteLine("Done copying.");
    }
    private static IMediaProcessor GetLatestMediaProcessorByName(CloudMediaContext context, string mediaProcessorName)
    {
        // The possible strings that can be passed into the 
        // method for the mediaProcessor parameter:
        // Windows Azure Media Encoder
        // Windows Azure Media Packager
        // Windows Azure Media Encryptor
        //   Storage Decryption
    
        var processor = context.MediaProcessors.Where(p => p.Name == mediaProcessorName).
            ToList().OrderBy(p => new Version(p.Version)).LastOrDefault();
    
        if (processor == null)
            throw new ArgumentException(string.Format("Unknown media processor", mediaProcessorName));
    
        return processor;
    }
    
    // This method is a handler for events that track job progress.   
    private static void StateChanged(object sender, JobStateChangedEventArgs e)
    {
        Console.WriteLine("Job state changed event:");
        Console.WriteLine("  Previous state: " + e.PreviousState);
        Console.WriteLine("  Current state: " + e.CurrentState);
    
        switch (e.CurrentState)
        {
            case JobState.Finished:
                Console.WriteLine();
                Console.WriteLine("********************");
                Console.WriteLine("Job is finished.");
                Console.WriteLine("Please wait while local tasks or downloads complete...");
                Console.WriteLine("********************");
                Console.WriteLine();
                Console.WriteLine();
                break;
            case JobState.Canceling:
            case JobState.Queued:
            case JobState.Scheduled:
            case JobState.Processing:
                Console.WriteLine("Please wait...\n");
                break;
            case JobState.Canceled:
            case JobState.Error:
                // Cast sender as a job.
                IJob job = (IJob)sender;
                // Display or log error details as needed.
                LogJobStop(null, job.Id);
                break;
            default:
                break;
        }
    }
    
    private static void LogJobStop(CloudMediaContext context, string jobId)
    {
        StringBuilder builder = new StringBuilder();
        IJob job = GetJob(context, jobId);
    
        builder.AppendLine("\nThe job stopped due to cancellation or an error.");
        builder.AppendLine("***************************");
        builder.AppendLine("Job ID: " + job.Id);
        builder.AppendLine("Job Name: " + job.Name);
        builder.AppendLine("Job State: " + job.State.ToString());
        builder.AppendLine("Job started (server UTC time): " + job.StartTime.ToString());
        // Log job errors if they exist.  
        if (job.State == JobState.Error)
        {
            builder.Append("Error Details: \n");
            foreach (ITask task in job.Tasks)
            {
                foreach (ErrorDetail detail in task.ErrorDetails)
                {
                    builder.AppendLine("  Task Id: " + task.Id);
                    builder.AppendLine("    Error Code: " + detail.Code);
                    builder.AppendLine("    Error Message: " + detail.Message + "\n");
                }
            }
        }
        builder.AppendLine("***************************\n");
        // Write the output to a local file and to the console. The template 
        // for an error output file is:  JobStop-{JobId}.txt
        string outputFile = OutputFilesFolder + @"\JobStop-" + JobIdAsFileName(job.Id) + ".txt";
        WriteToFile(outputFile, builder.ToString());
        Console.Write(builder.ToString());
    }
    
    private static void LogJobDetails(CloudMediaContext context, string jobId)
    {
        StringBuilder builder = new StringBuilder();
        IJob job = GetJob(context, jobId);
    
        builder.AppendLine("\nJob ID: " + job.Id);
        builder.AppendLine("Job Name: " + job.Name);
        builder.AppendLine("Job submitted (client UTC time): " + DateTime.UtcNow.ToString());
    
        // Write the output to a local file and to the console. The template 
        // for an error output file is:  JobDetails-{JobId}.txt
        string outputFile = OutputFilesFolder + @"\JobDetails-" + JobIdAsFileName(job.Id) + ".txt";
        WriteToFile(outputFile, builder.ToString());
        Console.Write(builder.ToString());
    }
    
    // Replace ":" with "_" in Job id values so they can 
    // be used as log file names.  
    private static string JobIdAsFileName(string jobID)
    {
        return jobID.Replace(":", "_");
    }
    
    // Write method output to the output files folder.
    private static void WriteToFile(string outFilePath, string fileContent)
    {
        StreamWriter sr = File.CreateText(outFilePath);
        sr.WriteLine(fileContent);
        sr.Close();
    }
    
    private static IJob GetJob(CloudMediaContext context, string jobId)
    {
        // Use a Linq select query to get an updated 
        // reference by Id. 
        var jobInstance =
            from j in context.Jobs
            where j.Id == jobId
            select j;
    
        // Return the job reference as an Ijob. 
        IJob job = jobInstance.FirstOrDefault();
    
        return job;
    }
    
    private static IAsset GetAsset(CloudMediaContext context, string assetId)
    {
        // Use a LINQ Select query to get an asset.
        var assetInstance =
            from a in context.Assets
            where a.Id == assetId
            select a;
    
        // Reference the asset as an IAsset.
        IAsset asset = assetInstance.FirstOrDefault();
    
        return asset;
    }
    
    public static void DeleteAllAssets(CloudMediaContext context)
    {
        // Loop through and delete all assets.
        foreach (IAsset asset in context.Assets)
        {
            DeleteLocatorsForAsset(context, asset);
    
            asset.Delete();
        }
    }
    
    public static void DeleteLocatorsForAsset(CloudMediaContext context, IAsset asset)
    {
        string assetId = asset.Id;
        var locators = from a in context.Locators
                        where a.AssetId == assetId
                        select a;
        foreach (var locator in locators)
        {
            Console.WriteLine("Deleting locator {0} for asset {1}", locator.Path, assetId);
    
            locator.Delete();
        }
    }
    
    public static void DeleteAccessPolicy(CloudMediaContext context, string existingPolicyId)
    {
        // To delete a specific access policy, get a reference to the policy.  
        // based on the policy Id passed to the method.
        var policyInstance =
                from p in context.AccessPolicies
                where p.Id == existingPolicyId
                select p;
    
        IAccessPolicy policy = policyInstance.FirstOrDefault();
    
        policy.Delete();
    
    }
    
    //////////////////////////////////////////////////////
    /// The following methods use REST calls.
    //////////////////////////////////////////////////////
    
    public static string GetAcsBearerToken(string clientId, string clientSecret, string scope, string accessControlServiceUri)
    {
        if (string.IsNullOrEmpty(clientId))
            throw new ArgumentNullException("clientId");
    
        if (string.IsNullOrEmpty(clientSecret))
            throw new ArgumentNullException("clientSecret");
    
        if (string.IsNullOrEmpty(scope))
        {
            scope = "urn:WindowsAzureMediaServices";
        }
        else if (!scope.ToLower().StartsWith("urn:"))
        {
            scope = "urn:" + scope;
        }
    
        if (string.IsNullOrEmpty(accessControlServiceUri))
        {
            accessControlServiceUri = "https://wamsprodglobal001acs.accesscontrol.windows.net/v2/OAuth2-13";
        }
        else if (!accessControlServiceUri.ToLower().EndsWith("/v2/oauth2-13"))
        {
            accessControlServiceUri = accessControlServiceUri.TrimEnd('/') + "/v2/OAuth2-13";
        }
    
        HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(accessControlServiceUri);
        request.Method = "POST";
        request.ContentType = "application/x-www-form-urlencoded";
        request.KeepAlive = true;
        string acsBearerToken = null;
    
        var requestBytes = Encoding.ASCII.GetBytes("grant_type=client_credentials&client_id=" +
            clientId + "&client_secret=" + HttpUtility.UrlEncode(clientSecret) +
            "&scope=" + HttpUtility.UrlEncode(scope));
        request.ContentLength = requestBytes.Length;
    
        var requestStream = request.GetRequestStream();
        requestStream.Write(requestBytes, 0, requestBytes.Length);
        requestStream.Close();
    
        var response = (HttpWebResponse)request.GetResponse();
    
        if (response.StatusCode == HttpStatusCode.OK)
        {
            using (Stream responseStream = response.GetResponseStream())
            {
                using (StreamReader stream = new StreamReader(responseStream))
                {
                    string responseString = stream.ReadToEnd();
                    var reader = JsonReaderWriterFactory.CreateJsonReader(Encoding.UTF8.GetBytes(responseString),
                        new XmlDictionaryReaderQuotas());
    
                    while (reader.Read())
                    {
                        if ((reader.Name == "access_token") && (reader.NodeType == XmlNodeType.Element))
                        {
                            if (reader.Read())
                            {
                                acsBearerToken = reader.Value;
                                break;
                            }
                        }
                    }
                }
            }
        }
    
        return acsBearerToken;
    }
    
    public static XmlDocument CreateLocator(string mediaServicesApiServerUri,
                                            out string redirectedMediaServicesApiServerUri,
                                            string acsBearerToken, string assetId,
                                            string accessPolicyId, int locatorType,
                                            DateTime startTime, string locatorIdToReplicate = null,
                                            bool autoRedirect = true)
    {
        if (string.IsNullOrEmpty(mediaServicesApiServerUri))
        {
            mediaServicesApiServerUri = "https://media.windows.net/api/";
        }
        if (!mediaServicesApiServerUri.EndsWith("/"))
            mediaServicesApiServerUri = mediaServicesApiServerUri + "/";
    
        if (string.IsNullOrEmpty(acsBearerToken)) throw new ArgumentNullException("acsBearerToken");
        if (string.IsNullOrEmpty(assetId)) throw new ArgumentNullException("assetId");
        if (string.IsNullOrEmpty(accessPolicyId)) throw new ArgumentNullException("accessPolicyId");
    
        redirectedMediaServicesApiServerUri = null;
        XmlDocument xmlResponse = null;
    
        StringBuilder sb = new StringBuilder();
        sb.Append("{ \"AssetId\" : \"" + assetId + "\"");
        sb.Append(", \"AccessPolicyId\" : \"" + accessPolicyId + "\"");
        sb.Append(", \"Type\" : \"" + locatorType + "\"");
        if (startTime != DateTime.MinValue)
            sb.Append(", \"StartTime\" : \"" + startTime.ToString("G", CultureInfo.CreateSpecificCulture("en-us")) + "\"");
        if (!string.IsNullOrEmpty(locatorIdToReplicate))
            sb.Append(", \"Id\" : \"" + locatorIdToReplicate + "\"");
        sb.Append("}");
    
        string requestbody = sb.ToString();
    
        try
        {
            var request = GenerateRequest("POST", mediaServicesApiServerUri, "Locators",
                null, acsBearerToken, requestbody);
            var response = (HttpWebResponse)request.GetResponse();
    
            switch (response.StatusCode)
            {
                case HttpStatusCode.MovedPermanently:
                    //Recurse once with the mediaServicesApiServerUri redirect Location:
                    if (autoRedirect)
                    {
                        redirectedMediaServicesApiServerUri = response.Headers["Location"];
                        string secondRedirection = null;
                        xmlResponse = CreateLocator(redirectedMediaServicesApiServerUri,
                                                    out secondRedirection, acsBearerToken,
                                                    assetId, accessPolicyId, locatorType,
                                                    startTime, locatorIdToReplicate, false);
                    }
                    else
                    {
                        Console.WriteLine("Redirection to {0} failed.",
                            mediaServicesApiServerUri);
                        return null;
                    }
                    break;
                case HttpStatusCode.Created:
                    using (Stream responseStream = response.GetResponseStream())
                    {
                        using (StreamReader stream = new StreamReader(responseStream))
                        {
                            string responseString = stream.ReadToEnd();
                            var reader = JsonReaderWriterFactory.
                                CreateJsonReader(Encoding.UTF8.GetBytes(responseString),
                                    new XmlDictionaryReaderQuotas());
    
                            xmlResponse = new XmlDocument();
                            reader.Read();
                            xmlResponse.LoadXml(reader.ReadInnerXml());
                        }
                    }
                    break;
    
                default:
                    Console.WriteLine(response.StatusDescription);
                    break;
            }
        }
        catch (WebException ex)
        {
            Console.WriteLine(ex.Message);
        }
    
        return xmlResponse;
    }
    
    public static void CreateFileInfos(string mediaServicesApiServerUri,
                                string acsBearerToken,
                                string assetId
                                )
    {
        if (String.IsNullOrEmpty(mediaServicesApiServerUri))
        {
            mediaServicesApiServerUri = "https://media.windows.net/api/";
        }
        if (!mediaServicesApiServerUri.EndsWith("/"))
            mediaServicesApiServerUri = mediaServicesApiServerUri + "/";
    
        if (String.IsNullOrEmpty(acsBearerToken)) throw new ArgumentNullException("acsBearerToken");
        if (String.IsNullOrEmpty(assetId)) throw new ArgumentNullException("assetId");
    
    
        string id = assetId.Replace(":", "%");
    
        UriBuilder builder = new UriBuilder(mediaServicesApiServerUri);
        builder.Path = Path.Combine(builder.Path, "CreateFileInfos");
        builder.Query = String.Format(CultureInfo.InvariantCulture, "assetid='{0}'", assetId);
    
        try
        {
            var request = GenerateRequest("GET", mediaServicesApiServerUri, "CreateFileInfos",
                String.Format(CultureInfo.InvariantCulture, "assetid='{0}'", assetId), acsBearerToken, null);
    
            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
            {
                if (response.StatusCode == HttpStatusCode.MovedPermanently)
                {
                    string redirectedMediaServicesApiUrl = response.Headers["Location"];
    
                    CreateFileInfos(redirectedMediaServicesApiUrl, acsBearerToken, assetId);
                }
                else if ((response.StatusCode != HttpStatusCode.OK) &&
                    (response.StatusCode != HttpStatusCode.Accepted) &&
                    (response.StatusCode != HttpStatusCode.Created) &&
                    (response.StatusCode != HttpStatusCode.NoContent))
                {
                    // TODO: Throw a more specific exception.
                    throw new Exception("Invalid response received ");
                }
            }
        }
        catch (WebException ex)
        {
            Console.WriteLine(ex.Message);
        }
    }
    
    
    private static HttpWebRequest GenerateRequest(string verb,
                                                    string mediaServicesApiServerUri,
                                                    string resourcePath, string query,
                                                    string acsBearerToken, string requestbody)
    {
        var uriBuilder = new UriBuilder(mediaServicesApiServerUri);
        uriBuilder.Path += resourcePath;
        if (query != null)
        {
            uriBuilder.Query = query;
        }
        HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(uriBuilder.Uri);
        request.AllowAutoRedirect = false; //We manage our own redirects.
        request.Method = verb;
    
        if (resourcePath == "$metadata")
            request.MediaType = "application/xml";
        else
        {
            request.ContentType = "application/json;odata=verbose";
            request.Accept = "application/json;odata=verbose";
        }
    
        request.Headers.Add("DataServiceVersion", "3.0");
        request.Headers.Add("MaxDataServiceVersion", "3.0");
        request.Headers.Add("x-ms-version", "2.1");
        request.Headers.Add(HttpRequestHeader.Authorization, "Bearer " + acsBearerToken);
    
        if (requestbody != null)
        {
            var requestBytes = Encoding.ASCII.GetBytes(requestbody);
            request.ContentLength = requestBytes.Length;
    
            var requestStream = request.GetRequestStream();
            requestStream.Write(requestBytes, 0, requestBytes.Length);
            requestStream.Close();
        }
        else
        {
            request.ContentLength = 0;
        }
        return request;
    }
    
    
    

È ora possibile usare un servizio di gestione del traffico per indirizzare le richieste tra i due data center e quindi il failover in caso di interruzioni.

Il documento è risultato utile?
(1500 caratteri rimanenti)
Grazie per i commenti inviati.
Mostra:
© 2015 Microsoft