Azure Function 3.0 Service Bus triggered sometimes throws Microsoft.Azure.ServiceBus.MessageLockLostException

0
votes

I know Azure Functions 3.0 is in preview but so we better catch up bugs sooner than later.

My function is triggered by Service Bus queue messages. In my case, I have 2 processes sending a message every 15 minutes. So the Azure Func is not really busy.

Most of the time there are no problems, but about 2 times a day I get these errors:

Microsoft.Azure.ServiceBus.MessageLockLostException: at Microsoft.Azure.ServiceBus.Core.MessageReceiver+d__99.MoveNext (Microsoft.Azure.ServiceBus, Version=4.1.1.0, Culture=neutral, PublicKeyToken=7e34167dcc6d6d8c) at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e) at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e) at Microsoft.Azure.ServiceBus.RetryPolicy+d__19.MoveNext (Microsoft.Azure.ServiceBus, Version=4.1.1.0, Culture=neutral, PublicKeyToken=7e34167dcc6d6d8c) at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e) at Microsoft.Azure.ServiceBus.RetryPolicy+d__19.MoveNext (Microsoft.Azure.ServiceBus, Version=4.1.1.0, Culture=neutral, PublicKeyToken=7e34167dcc6d6d8c) at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e) at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e) at Microsoft.Azure.ServiceBus.Core.MessageReceiver+d__68.MoveNext (Microsoft.Azure.ServiceBus, Version=4.1.1.0, Culture=neutral, PublicKeyToken=7e34167dcc6d6d8c) at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e) at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e) at Microsoft.Azure.ServiceBus.MessageReceivePump+d__16.MoveNext (Microsoft.Azure.ServiceBus, Version=4.1.1.0, Culture=neutral, PublicKeyToken=7e34167dcc6d6d8c)

I changed message TTL = 30 min, Lock duration = 2 min, Max Delivery Count = 10 (default). So these settings shouldn't affect anything I believe.

Can anyone tell me why do I get these errors and how to fix this?

1
azure.net-coreazure-functionsazureservicebus

1 Answers

2
votes

MessageLockLostException indicates that your Function has taken longer than the defined LockDuration in the queue to process the message. You could increase the time up to 5 minutes, but that still might occur. I would recommend to log execution time and analyze how long did it take your Function when the exception is thrown.

Side note: TimeToLive and MaxDeliveryCount are not related to this issue.