Azure Function App Azure Service Bus触发器两次触发 [英] Azure Function App Azure Service Bus trigger triggers twice
问题描述
我正在将Azure Function应用程序与服务总线触发器一起使用，以读取服务总线并处理服务总线消息的内容.服务总线接收JSON序列化的对象，然后我将JSON消息反序列化回Function App中的对象.但是，由于某种原因，每当有东西发送到服务总线时，触发器就会触发两次，其中一个是JSON消息，另一个是包含服务总线消息"文本的消息.
I'm using Azure Function Apps with a service bus trigger to read a service bus and do stuff with the contents of the service bus message. The service bus receives a JSON serialized object and then I de-serialize the JSON message back to the object in the Function App. However, for some reason whenever something gets sent to the service bus, the trigger fires twice with one being the JSON message and one being a message containing text "Service Bus Message".
我不知道是什么导致第二条消息，所以我想到的只是反序列化服务总线消息，当它因服务总线消息"而失败时，我将捕获异常并忽略它.但是，我认为这不是处理此问题的正确方法，JSON反序列化中的实际错误将被忽略.处理第二条消息的正确方法是什么?
I have no idea what causes the second message, so what I came up with is just de-serializing the service bus message and when it fails with the "Service Bus Message", I'll just catch the exception and ignore it. However, I don't think this is the right way to handle this issue and actual errors in JSON de-serialization will be ignored. What is the correct way to handle the second message?
示例代码:
using Newtonsoft.Json;
public static void Run(string myQueueItem, ILogger log, out SendGridMessage mailMessage)
{
MyClass myObject = null;
try
{
myObject = JsonConvert.DeserializeObject<MyClass>(myQueueItem);
// do stuff
}
catch (JsonException je)
{
// ignore this exception
}
catch (Exception e)
{
// handle the other exceptions and send an alert
}
}
在原始文章中我没有提到的一件事是我也有一个SendGrid输出.我不明白为什么这会对触发器产生任何影响，所以我将其遗漏了.但是，我现在添加它，以防万一它可能是出于某些奇怪的原因.
One thing I did leave out in the original post is that I do have a SendGrid output too. I don't see why that would have any effect on the trigger which is why I left it out. However, I'm adding it now just in case it might be the cause for some weird reason.
添加了突出显示该问题的完整工作代码
Edit 2: Added full working code that highlights the issue
// Sender
using System;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Azure.ServiceBus;
using Newtonsoft.Json;
namespace myapp
{
class Program
{
static void Main(string[] args) => MainAsync().GetAwaiter().GetResult();
static async Task MainAsync()
{
string serviceBusConnectionString = "<your servicebus connectionstring>";
string queueName = "<your queue name>";
IQueueClient queueClient = new QueueClient(serviceBusConnectionString, queueName);
string messageBody = JsonConvert.SerializeObject(new Test());
var message = new Message(Encoding.UTF8.GetBytes(messageBody));
await queueClient.SendAsync(message);
await queueClient.CloseAsync();
}
class Test
{
public string Text { get; set; } = "test";
}
}
}
// Receiver
#r "Newtonsoft.Json"
using System;
using System.Threading.Tasks;
using Newtonsoft.Json;
public static void Run(string myQueueItem, ILogger log)
{
try
{
Test test = JsonConvert.DeserializeObject<Test>(myQueueItem);
log.LogInformation($"C# ServiceBus queue trigger function processed message: {test.Text}");
}
catch (Exception e)
{
log.LogInformation($"Exception: {e.Message}");
}
}
class Test
{
public string Text { get; set; } = "test";
}
结果:
2019-11-04T08:38:10.544 [Information] Executing 'Functions.test' (Reason='This function was programmatically called via the host APIs.', Id=06e10006-baa6-430f-b5db-9a5eae5c154c)
2019-11-04T08:38:10.659 [Information] Exception: Unexpected character encountered while parsing value: S. Path '', line 0, position 0. // This here is caused by "Service bus message"
2019-11-04T08:38:10.659 [Information] Executed 'Functions.test' (Succeeded, Id=06e10006-baa6-430f-b5db-9a5eae5c154c)
2019-11-04T08:39:02.582 [Information] Executing 'Functions.test' (Reason='New ServiceBus message detected on 'test'.', Id=5d7622a7-cc8d-44c9-8720-626fdbb8cabb)
2019-11-04T08:39:02.583 [Information] Trigger Details: MessageId: 13bba779fd524fa1a0098acd6634aded, DeliveryCount: 1, EnqueuedTime: 11/4/2019 8:39:02 AM, LockedUntil: 11/4/2019 8:39:07 AM
2019-11-04T08:39:02.584 [Information] C# ServiceBus queue trigger function processed message: test // This here is the actual message
2019-11-04T08:39:02.584 [Information] Executed 'Functions.test' (Succeeded, Id=5d7622a7-cc8d-44c9-8720-626fdbb8cabb)
推荐答案
根据我的测试，触发器不会被触发两次.
Based on my test, the trigger will not be triggered twice.
namespace ServiceBusTrigger
{
public static class Function1
{
[FunctionName("Function1")]
public static void Run([ServiceBusTrigger("myqueue", Connection = "ServiceBusConnection")]string myQueueItem, ILogger log)
{
log.LogInformation($"C# ServiceBus queue trigger function processed message: {myQueueItem}");
var myMessage = JsonConvert.DeserializeObject<MyMessage>(myQueueItem);
log.LogInformation($"ID: {myMessage.id}\tContent:{myMessage.content}");
}
}
}
手动发送消息，并获得以下输出:
Send a message manually, and get the following output:
Pause Clear Expand
2019-11-04T08:18:56.837 [Information] Executing 'Function1' (Reason='New ServiceBus message detected on 'myqueue'.', Id=7fb37483-b9a3-4c19-baa3-235b419bb585)
2019-11-04T08:18:56.837 [Information] Trigger Details: MessageId: c00a8e41-d883-4620-992f-6b9b4fdae320, DeliveryCount: 1, EnqueuedTime: 11/4/2019 8:18:56 AM, LockedUntil: 11/4/2019 8:19:26 AM
2019-11-04T08:18:56.838 [Information] C# ServiceBus queue trigger function processed message: {"id":"1","content":"abc"}
2019-11-04T08:18:56.838 [Information] ID: 1 Content:abc
2019-11-04T08:18:56.839 [Information] Executed 'Function1' (Succeeded, Id=7fb37483-b9a3-4c19-baa3-235b419bb585)
那么，您能否检查您的服务总线生产商，以查看是否发送了其他任何消息.
So, could you please check your service bus producer to see if any additional message was sent.
您只能停止功能应用程序，手动发送消息并在门户上检查:
Of you can just stop your function app, send a message manually and check on the portal:
如果一切正常，则应该只有1条活动消息.
If everything was fine, then there should only be 1 active message.
更新
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