Sporadic C# compilation issue

[fabiocav]

Over the past few days, a few function apps have run into a compilation failure that seems to be caused by an attempt to queue additional Roslyn compilation events after the compilation is marked as completed, leading to an InvalidOperationException with the message: Cannot enqueue data after PromiseNotToEnqueue.

Opening this for investigation and tracking.

[paulbatum]

Looks like a Roslyn issue, we are following up with them.

[paulbatum]

@fabiocav any updates on this? If we don't have a date for when this is likely to be unblocked I think I should move it out of the January milestone.

[fabiocav]

Still an ongoing discussion with the team. It's not likely to be unblocked in this milestone, but it sounds like there has been some work done to address this issue in 2.0.0 (Roslyn)

[DamianFlynn]

This is still happening, three different function apps, and different functions within each app are now presenting the same problem as covered here. Just to confirm that restarting the Web Application sorts out the issue for now

[fabiocav]

@DamianFlynn thank you for reporting. Unfortunately, a restart is indeed the way to address this at the moment, but we understand this is not ideal. We'll be working on updating the compiler references soon, now that 2.0 has been released, both, to address issues like this and bring C# 7.0 support.

[tomasmcguinness]

This issue occurred in a Queue bound function yesterday, nearly ruining a demo we were giving to a customer. The function in question was deployed weeks ago and just suddenly stopped working. As we're using the consumption model, I didn't find an obvious way to restart them as suggested by @DamianFlynn. I just disabled and reenabled the function, which seems to have solved the issue. Do you have an ETA on when this will be resolved?

[mamaso]

Ran into this here as well: http://stackoverflow.com/questions/43085082/azure-function-with-servicebustrigger-stops-receiving-messages?noredirect=1#comment73298766_43085082

[DamianFlynn]

I am currently converting my solution to a class library. Will this approach circumvent the problem until such time as 2.0 is live? Thanks Get Outlook for iOS<https://aka.ms/o0ukef>

…

________________________________ From: Fabio Cavalcante <notifications@github.com> Sent: Thursday, March 23, 2017 5:27:53 PM To: Azure/azure-webjobs-sdk-script Cc: Damian Flynn; Mention Subject: Re: [Azure/azure-webjobs-sdk-script] Sporadic C# compilation issue (#999) @DamianFlynn<https://github.com/DamianFlynn> thank you for reporting. Unfortunately, a restart is indeed the way to address this at the moment, but we understand this is not ideal. We'll be working on updating the compiler references soon, now that 2.0 has been released, both, to address issues like this and bring C# 7.0 support. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<#999 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AF_zD6I7Ftxj8btjo0yl6yYGTlRI20EOks5roquZgaJpZM4K-Tqm>.

[mathewc]

Assigning this back to triage so we can get traction on this - customers are hitting this, and we're also seeing this in our runner from time to time, generating sev 2 incidents.

[gibwar]

Just ran in to this issue today as well on an HTTP triggered function. Restarting the app service brought everything back up. Also on consumption plan.

@tomasmcguinness: you can restart the service by going to the function app like normal, then function app settings, and under the "Manage" section click on "Go to App Service Settings" and from there you can stop and start it like a normal app service.

[fabiocav]

Reopening for triage as this did not get resolved as expected

[fabiocav]

Thank you @tangozulu32123. This is assigned to the current sprint and we hope to have additional fixes and mitigation steps for this issue soon.

[fabiocav]

Updating milestone to better reflect when this will be done.

[bonserem]

Ran into this issue twice (March and April 2018)with an Function App with a Eventbus trigger twice. Restart fixed it. Problem was it took days to find out it wasnt running...

[sisoje]

same here, restart was needed

[mathewc]

I recently opened #3145 for this as well.

[snbcdev]

Ran into this issue over the weekend, our function app stopped working on 7/28/18 at 11:51 PM Pacific Time. When I logged into Azure Portal and looked at the app's code, I saw the erorr notification with the message "Cannot enqueue data after PromiseNotToEnqueue." Restarting the app fixed it.

[mathewc]

Guys - we're looking at this now and will get a fix out for this ASAP.

[Kapster17]

Same issue we have started facing with our function that's triggered by an event-hub.
The function executing is critical to our application.

Any workaround until we have a fix ?

Thanks

[paulbatum]

Until the fix is deployed globally, the best workaround is to switch to writing your function as a class library in VS or VS code (e.g. https://docs.microsoft.com/en-us/azure/azure-functions/functions-develop-vs) so that you are deploying .dll files to your function app and no compilation is required on the server side. I understand that moving from csx to cs is not 100% trivial and it might not be viable, but I would say that we are still at least a week away from having this fix be deployed globally so you might want to consider it. Sorry I dont have a better workaround to share right now.

[IvanovOleg]

This issue still exists!

[gridr-ch]

Hi @paulbatum ,
Is there an update / fix to this issue?

[paulbatum]

It seems that despite multiple attempts to address this issue through roslyn updates and other mitigations, this error can still occur. I don't have any updates to share at this time. The same recommendation that I made before still applies - you can completely avoid impact by deploying compiled binaries. Our dev tools in VS and VS Code make this straightforward.

[paulbatum]

We are planning on taking another Roslyn update (see the issue referenced above).

[Hazhzeng]

Another customer is raising the same issue 183252697.

[paulbatum]

The Roslyn update when live in May 2020 and as far as I'm aware there have been no further reports of the issue since then, closing.

[ConnorMcMahon]

We saw another issue of this appear on the latest version of V3 on an internal support case.