为通过 Azure 函数输出绑定添加到 Azure 队列的消息设置 VisibilityTimeout

Question

我有一个 TimerTrigger 函数，输出绑定是一个 Azure 队列。

我的想法是，每隔 10 分钟，计时器就会运行，它会查看我的数据库中的一个视图，并遍历所有返回的行，将它们作为消息添加到队列中。

下面是我的示例 TimerTrigger。将消息添加到队列中效果很好。

然而，在我的真实场景中，某些行需要立即执行，而其他行将延迟几分钟（每行不同）。我计划通过对消息使用 VisibilityTimeout 来处理延迟。

不幸的是，通过字符串的绑定不允许我设置值。 CloudQueueMessage.VisiblityTimeout（下面使用）是只读的。

#r "Microsoft.WindowsAzure.Storage"

using System;
using Microsoft.WindowsAzure.Storage.Queue;

public static void Run(TimerInfo myTimer,  ICollector<CloudQueueMessage> outputQueueItem, TraceWriter log)
{
    log.Info($"C# Timer trigger function executed at: {DateTime.Now}");    


    //- Add a message to be processed now.
    CloudQueueMessage msg = new CloudQueueMessage("Now");
    outputQueueItem.Add(msg);

    //- Add a message to be processed later.
    //- this code below won't work because NextVisibleTime is readonly.
    //- is there some way to set the VisibilityTimeout property before queueing?
    msg = new CloudQueueMessage("Later");
    DateTime otherDate = DateTime.Now.AddMinutes(3);

    msg.NextVisibleTime = otherDate;
    outputQueueItem.Add(msg);

}

有没有什么方法可以让绑定将消息添加到队列中，并让我根据需要逐条消息设置 VisibilityTimeout 消息？

Answer 1

Azure Functions Storage Queue 的输出绑定只允许我们访问 CloudQueueMessage，不允许我们为消息设置 VisibilityTimeout。

我重写了我的代码以连接到 Azure 存储队列并post手动将消息发送到队列，而不是通过 Azure 函数输出绑定。

见下文。 . .

#r "Microsoft.WindowsAzure.Storage" 

using System;
using System.Configuration;
using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Queue;

public static void Run(TimerInfo myTimer, TraceWriter log)
{    
    log.Info($"Queue Notifications: {DateTime.Now}, {myTimer.Schedule}, {myTimer.ScheduleStatus}, {myTimer.IsPastDue}");

    //* Setup the connection to q-notifications, create it if it doesn't exist.
    var connectionString = ConfigurationManager.AppSettings["AzureWebJobsStorage"]; 
    var storageAccount = CloudStorageAccount.Parse(connectionString);
    var queueClient = storageAccount.CreateCloudQueueClient();
    var queue = queueClient.GetQueueReference("q-notifications");
    queue.CreateIfNotExistsAsync();

    //* Eventually this will come from iterating through a SQL Database View of messages that need queueing.
    //* For testing just show we can add two messages with different Visibilty times.
    CloudQueueMessage message;
    TimeSpan delay;

    //* Queue Message for Immediate Processing.
    message = new CloudQueueMessage("Now Message");
    queue.AddMessageAsync(message, null, null, null, null);

    //* Queue Message for Later Processing.
    delay = DateTime.UtcNow.AddMinutes(3) - DateTime.UtcNow;
    message = new CloudQueueMessage("Later Message");
    queue.AddMessageAsync(message, null, delay, null, null);

    //* Queue Message for Even Later Processing.
    delay = DateTime.UtcNow.AddMinutes(12) - DateTime.UtcNow;
    message = new CloudQueueMessage("Even Later Message");
    queue.AddMessageAsync(message, null, delay, null, null);
}

为通过 Azure 函数输出绑定添加到 Azure 队列的消息设置 VisibilityTimeout

Setting the VisibilityTimeout for a Message added to an Azure Queue via Azure Function Output Binding

azure

visibility

azure-functions

azure-storage-queues