The message in the Service bus queue unlocks automatically before the Function App completes the processing. After unlocking the message, another instance of the function app read the same message from the queue and start processing.

Question

The message in the Service bus queue unlocks automatically before the Function App completes the processing. After unlocking the message, another instance of the function app read the same message from the queue and start processing.

Sinhal, Nikhil 20

The message in the Service bus queue unlocks automatically before the Queue triggered Function App completes the processing the message. After unlocking the message, another instance of the function app read the same message from the queue and start processing. Due to this, multiple instances try to insert same record in database table and gives primary key violation issue.

Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-10-29T14:45:12.2833333+00:00

Hello Sinhal, Nikhil,

What is the current lock duration of messages in Azure Service Bus?
Sinhal, Nikhil 20 Reputation points

2025-10-30T07:32:46.53+00:00

Default lock duration of service bus message is 1 minute that can be extended upto 5 minutes. In my case, the Azure function App is a long running process (> 30 min) hence wanted to extend/renew the lock on the message so that it shouldn't get unlock before the processing completes, otherwise the same message is picked by another instance of the Function App and starts processing the duplicate records.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-11-04T14:30:51.5+00:00

Hello Sinhal, Nikhil,

Are you running .NET Isolated or .NET In‑Process Functions for this Service Bus trigger?
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-11-05T16:28:52.1766667+00:00

Hello Sinhal, Nikhil,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Sinhal, Nikhil 20 Reputation points

2025-11-07T08:29:41.1833333+00:00
I am running .NET Isolated function.

Thanks @Praveen Kumar Gudipudi (Quadrant Technologies) for looking into this.

The issue has fixed now. To fix the issue, I programmatically refreshed the message lock on regular interval by calling the renew method as follows:

Task.Run(async () => {

while(flag)

{

await messageActions.RenewMessageLockAsync(message); ``` } } Note that, we need to call this method in a separate async call so the renew method will run in parallel to the business service call.

Answer accepted by question author

3 additional answers

Your answer

Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-10-29T14:45:12.2833333+00:00

Hello Sinhal, Nikhil,

What is the current lock duration of messages in Azure Service Bus?
Sinhal, Nikhil 20 Reputation points

2025-10-30T07:32:46.53+00:00

Default lock duration of service bus message is 1 minute that can be extended upto 5 minutes. In my case, the Azure function App is a long running process (> 30 min) hence wanted to extend/renew the lock on the message so that it shouldn't get unlock before the processing completes, otherwise the same message is picked by another instance of the Function App and starts processing the duplicate records.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-11-04T14:30:51.5+00:00

Hello Sinhal, Nikhil,

Are you running .NET Isolated or .NET In‑Process Functions for this Service Bus trigger?
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-11-05T16:28:52.1766667+00:00

Hello Sinhal, Nikhil,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Sinhal, Nikhil 20 Reputation points

2025-11-07T08:29:41.1833333+00:00

I am running .NET Isolated function.

Thanks @Praveen Kumar Gudipudi (Quadrant Technologies) for looking into this.

The issue has fixed now. To fix the issue, I programmatically refreshed the message lock on regular interval by calling the renew method as follows:

Task.Run(async () => {

while(flag)

{

await messageActions.RenewMessageLockAsync(message); ``` } } Note that, we need to call this method in a separate async call so the renew method will run in parallel to the business service call.

Answer 1

Praveen Kumar Gudipudi 1,495 Microsoft External Staff Moderator

Hello Sinhal, Nikhil,

To fix the issue, I programmatically refreshed the message lock on regular interval by calling the renew method as follows:

Task.Run(async () => {

while(flag)

{

await messageActions.RenewMessageLockAsync(message);

}

Please accept as answer and do a Thumbs-up to upvote this response if you are satisfied with the community help. Your upvote will be beneficial for the community users facing similar issues.

User's image

Answer 2

Praveen Kumar Gudipudi 1,495 Microsoft External Staff Moderator

Hello Sinhal, Nikhil,

The auto-renewal feature is available for Azure Functions when they are triggered by Service Bus and allows you to set the maxAutoRenewDuration in the host.json file.

Maximum value: The maximum duration you can configure for auto-renew is 30 minutes.

This means if your function is running for longer than 30 minutes, the auto-renew feature won’t be enough, and you'll have to implement manual lock renewal within your function to keep the message locked for longer periods.

If your function is running for a long time (and less than 30 minutes), you can configure auto-renew in the host.json file like this:

{

"version": "2.0",

"extensions": {

"serviceBus": {

  "messageHandlerOptions": {

    "autoComplete": false,  // Don't auto-complete the message

    "maxAutoRenewDuration": "00:30:00"  // Max auto-renew duration (30 minutes)

  }

}

}

Please accept as answer and do a Thumbs-up to upvote this response if you are satisfied with the community help. Your upvote will be beneficial for the community users facing similar issues.

User's image

Sinhal, Nikhil 20 Reputation points

2025-10-31T11:58:23.55+00:00

Hi @Praveen Kumar Gudipudi

I had tried the same as suggested to set maxAutoRenewDuration in host file but it didn't lock message for 30 min and the message get picked by Function App again after 5 min.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-11-03T14:56:01.0033333+00:00

Hello Sinhal, Nikhil,

Are you running .NET Isolated or .NET In‑Process Functions for this Service Bus trigger?

Answer 3

Sinhal, Nikhil 20

To fix the issue, I programmatically refreshed the message lock on regular interval by calling the renew method as follows:

Task.Run(async () => {

while(flag)

{

SQL

await messageActions.RenewMessageLockAsync(message);

}

Please accept as answer and do a Thumbs-up to upvote this response if you are satisfied with the community help. Your upvote will be beneficial for the community users facing similar issues.

Answer 4

Sinhal, Nikhil 20

Issue is fixed now.

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The message in the Service bus queue unlocks automatically before the Function App completes the processing. After unlocking the message, another instance of the function app read the same message from the queue and start processing.

3 additional answers

Your answer