Hi @moodya , have you checked out the docs at https://docs.microsoft.com/en-us/aspnet/core/tutorials/grpc/grpc-start?view=aspnetcore-3.0&tabs=visual-studio ?

If you're running into a problem, please let us know and we can investigate.

@shirhatti - any idea on this?

Can't host gRPC in IIS/Azure App Service.
The HTTP/2 implementation of Http.Sys does not support HTTP response trailing headers which gRPC relies on.

The recommended approach is to host your gRPC service on AKS.

As far as App Service timelines go, I'd defer to @stefsch

I'm currently expecting issues to do this. I got a gRPC service running well using aspnetcore 3 preview 3 and Kestrel. But, an error about trailers appears using IIS when the service send the response (the request is well received) :
gPRC error => 2 UNKNOWN: No status received)
Dotnet error => "Trailers are not supported for this response" in Microsoft.AspNetCore.Http.ResponseTrailerExtensions.AppendTrailer(HttpResponse response, String trailerName, StringValues trailerValues) at Grpc.AspNetCore.Server.Internal.HttpResponseExtensions.ConsolidateTrailers...

Following this exchange https://forums.iis.net/p/1241598/2147837.aspx?p=True&t=636917571046786374, it seems that is not the responsibilty of the web server to handle gRPC. gPRC use HTTP/2, IIS supports HTTP/2, so it must works. If it's not, it's a bug from IIS or, more possible, from dotnetcore.

Thanks, I missed it and it makes sense with my issue.
@shirhatti the support is planned on the roadmap ?

We (IIS) are currently evaluating whether to support HTTP response trailers. No roadmaps/commitments I can speak to yet.

@shirhatti Given gRPC seems to be a major feature of .NET Core 3 (https://github.com/grpc/grpc-dotnet), it would be a real shame if it's not hostable in IIS/App Service given so many .NET web applications are hosted on those. I hope the availability of that feature in .NET Core helps drive your roadmap.

I fully agree with @jbrantly. gRPC is advertised as one of the main features of .NET Core 3.
It should be hostable in IIS/Azure App Services.
@shirhatti please consider adding this to the roadmap

I couldn't agree more.

We're looking into it. It requires both Windows kernel changes and IIS changes.

@davidfowl will this be possible when .NET Core 3 is released?
Ability to host GRPC in App Services is a blocker for me.

Well is May 29 of 2019, and yet there is not signal that this will be possible. I'm looking for host a GRPC service in IIS and add a certificate to use HTTPS :(

No it's not possible on IIS, we're working on getting changes but it will be a slow process (as it requires a windows update).

I roughly lost about 3 days... thanks iis

Hi @davidfowl
Any update?

@davidfowl any chance this might get added before .NET Core 3.0 gets released? Or should we wait for 3.1 or 5.0?

No as it requires windows changes. It’s not going to be part of 3.0 and it will require the latest version of Windows (whatever that is at the time) to get these features. There’s no ETA

we were told it was a windows kernel issue.

Yes getting the Windows kernel features was necessary for anyone wanting to run gRPC locally in IIS or Http.Sys. Those features have now shipped in Win11 and Server 2022.

The Azure experience has many other parts that need to be updated/replaced to enable an end-to-end cloud experience.

Status:

• We know this is important to you and we're working to make it happen.
• .NET has the necessary components to enable this.
• gRPC is now supported in IIS and Http.Sys locally on Win11 and Server 2022.
• Several layers of Azure services need to be updated/replaced to enable this end-to-end. That work is progressing.
• That progress won't be visible until an end-to-end experience is available.
• We can't give an ETA.

I know you said you can't give an ETA but at least a time frame? Is this going to take few weeks, months or years?

@czmirek You missed a 0.

Currently, I don't think there is any reason for us to use Windows on Azure. The problem is that with App Service, we can't use grpc even if we use Linux. This means that it's time for us to forget about Windows. It's best to use it on Linux with AKS or Azure Container Apps. I recommend it. That is my conclusion after waiting for 3 years.

We moved on. Our initial goal was to run grpc on App Services, but thankfully we moved on and containerized the application and deployed to Container Instances, where it worked just fine. This past month we moved the app to Container Apps, where grpc also works well.

It is possible to host gRPC in IIS on Win Server 2019? Or plan to make it happen ?

No there's no plans to backport this to 2019 AFAIK.

With Container Instances we were running 8 of them in development, with minimal resources (0.25 CPU and 0.2 GiB) and the cost was around $70 a month, combined. Now that we have changed to Container Apps the cost is going down significantly as the container apps can scale down to 0 when not in used, and we are not charged anything during that time. We still have not deployed the solution to production so I cannot give you a number yet. In production we will use containers with more resources AND where we will always have at least one container running. We won't scale down to zero in prod since it is noticeable the time it takes to wake up the containers once you make that first connection.

Congratulations, App Service now supports gRPC!
https://azure.github.io/AppService/2022/05/23/gRPC-support-on-App-Service.html
🎊🎉✨

Congratulations, App Service now supports gRPC! https://azure.github.io/AppService/2022/05/23/gRPC-support-on-App-Service.html 🎊🎉✨

Well done team! Timely too - I have customers who are looking to migrate some apps from WCF to be rewritten in gRPC on Azure. Great stuff.

It's available only in the EUAP regions....e.g. not yet accessible in normal regions.

Hello, @davidfowl!

Is it available already on Brazil South region? I've followed the given instructions but there is no connectivity through the public IP...

Thank you!

Update: This is now available in most regions.
https://azure.github.io/AppService/2022/08/16/A-Heavy-Lift.html
https://github.com/Azure/app-service-linux-docs/blob/master/HowTo/gRPC/use_gRPC_with_dotnet.md

Update: This is now available in most regions. https://azure.github.io/AppService/2022/08/16/A-Heavy-Lift.html https://github.com/Azure/app-service-linux-docs/blob/master/HowTo/gRPC/use_gRPC_with_dotnet.md

Absolutely amazing work, guys!

Closing this issue as complete.

Thanks for everyone's interest and passion for gRPC on IIS and Azure App Service. It took a while, but the final solution created many improvements in Azure App Service.

https://azure.github.io/AppService/2022/08/16/A-Heavy-Lift.html

Do we have the support for gRPC in Azure App Service on Windows? Or is it just a Linux thing?

It's only available on Linux, not Windows.

A couple of reasons I think this should be closed:

• The capability exists.
• This isn't the place for tracking app service issues. We left it open for a long time because there was lots of engagement here but this isn't where those feature requests or issues are tracked.
• A majority of customers wanting gRPC will be fine with Linux, at least to start with.

I'd suggest opening a new Feedback item for the app service team asking for support for Windows explicitly. Or you can use the existing one and pile onto it.

App Service Feedback link: https://feedback.azure.com/d365community/idea/108a4c91-c825-ec11-b6e6-000d3a4f0f1c

This thread is super long and has lots of useful information that is hard to find. I updated the original description with the latest status of things. Hope that helps!

Thanks all!

@davidfowl -- it's disappointing to see Microsoft's support for Windows fall further and further behind their support for Linux.

@davidfowl @Eilon will this work with a windows server 2022 container?