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

And container apps would be more expensive than app services?

Not necessarily. It's a different model (serverless) so depending on your app and its usage pattern it could be cheaper, or it could be more expensive. Running an app continuously is roughly comparable to an S1 App Plan. But then it can get cheaper with idle pricing or by scaling down to zero when it's not doing work. If it's intermittent work it could be dead cheap, even free.

Oner more question. Adding grpc-web to the grpc project as shown here

https://docs.microsoft.com/en-us/aspnet/core/grpc/browser?view=aspnetcore-5.0 titled "Use gRPC in browser apps"

has no impact whatsoever on the "hosting" question. Adding grpc-web to the solution only impacts whether browser based applications can call grpc services directly, right?

grpc web doesn't depend on HTTP/2 so it works anywhere.

grpc web doesn't depend on HTTP/2 so it works anywhere.

... with significantly less efficiency.

But yes, the .net GRPC client implementation will fall back automatically to GRPC-Web if it can't connect fully with regular GRPC. The same is true about the Dart library as well for Flutter.

Which we've leveraged to side step this issue, but it's a VERY significant impact on responsiveness and efficiency.

I am missing something.

My understanding was that first you create a grpc project (by adding the Grpc.AspNetCore NuGet package). If you want to expose the grpc project to browser applications then you add the Grpc.AspNetCore.Web package and do the proper configuration changes in the startup class. The point of adding grpc web being to expose the grpc services directly to browsers. I mentioned this because we followed the instructions described in the link above to add grpc-web to a project deployed on web apps and "still" does not work.

Are we to understand that by adding grpc-web to a grpc project that alone will make it run from a web app (app services)?

Finally, since container apps were mentioned above as now supporting grpc services I took a look on azure. To deploy a container app (preview) the options are:

1. Worskpace (vm)
2. Microsoft HPC Pack 2012 R2 (vm),
3. Windows 10 IoT Core Services (Azure service)
4. Web App (Azure service) --- Is this the same web app that we can't deploy grpc services to if we go the route of app services?
   From the options above, which one will support grpc as of today?

It would be very beneficial if this ASPNET CORE team developed some basic documentation on creating a basic Grpc service AND deploying it to Azure. After all, most of use creating apps with ASPNET CORE technologies look at Azure as the natural hosting solution. But, as far as I can see, there is no documentation that shows how to bring together all these technologies (including hosting).

I am missing something.

My understanding was that first you create a grpc project (by adding the Grpc.AspNetCore NuGet package). If you want to expose the grpc project to browser applications then you add the Grpc.AspNetCore.Web package and do the proper configuration changes in the startup class. The point of adding grpc web being to expose the grpc services directly to browsers. I mentioned this because we followed the instructions described in the link above to add grpc-web to a project deployed on web apps and "still" does not work.

Are we to understand that by adding grpc-web to a grpc project that alone will make it run from a web app (app services)?

Yes, you create a GRPC project, then add GRPC-Web and then it will work in a browser and .net client apps and dart as 2 examples will automatically fall back if http/2 isn't available or otherwise doesn't connect. It's less than ideal, but works. We did it because we were promised that this would be in production more than a year ago. We finally gave up and put it all in k8s with nginx as the RP.

It's a different story from IIS and App Service, but it seems that Azure Container Apps announced by Ignite can be used to host gRPC.
https://www.pulumi.com/blog/azure-container-apps/
https://techcommunity.microsoft.com/t5/apps-on-azure/introducing-azure-container-apps-a-serverless-container-service/ba-p/2867265

Perhaps now we should forget about IIS and App Services.

Just took a spin of Container App to run our gRPC service. Probably doing something wrong :D

upstream connect error or disconnect/reset before headers. reset reason: connection termination

It's a different story from IIS and App Service, but it seems that Azure Container Apps announced by Ignite can be used to host gRPC. https://www.pulumi.com/blog/azure-container-apps/ https://techcommunity.microsoft.com/t5/apps-on-azure/introducing-azure-container-apps-a-serverless-container-service/ba-p/2867265

Perhaps now we should forget about IIS and App Services.

Have you tried it out? did it work?

It's a different story from IIS and App Service, but it seems that Azure Container Apps announced by Ignite can be used to host gRPC. https://www.pulumi.com/blog/azure-container-apps/ https://techcommunity.microsoft.com/t5/apps-on-azure/introducing-azure-container-apps-a-serverless-container-service/ba-p/2867265

Perhaps now we should forget about IIS and App Services.

Have you tried it out? did it work?

One comment up..

It's a different story from IIS and App Service, but it seems that Azure Container Apps announced by Ignite can be used to host gRPC. https://www.pulumi.com/blog/azure-container-apps/ https://techcommunity.microsoft.com/t5/apps-on-azure/introducing-azure-container-apps-a-serverless-container-service/ba-p/2867265
Perhaps now we should forget about IIS and App Services.

Have you tried it out? did it work?

One comment up..

Yeah so you did not get it to work, i had hoped @takekazuomi did.
but i see now that he seems to be following your comment, so i guess not.
According to this earlier comment there are a lot of possible approaches, he might have tried an other one:
#9020 (comment)

Yeah so you did not get it to work, i had hoped @takekazuomi did. but i see now that he seems to be following your comment, so i guess not. According to this earlier comment there are a lot of possible approaches, he might have tried an other one: #9020 (comment)

We are now running on ACI. BUt of course container app with scaling options would be much nicer approach. now I need to dance with traffic manager to accomplish this.

We are now running on ACI. BUt of course container app with scaling options would be much nicer approach. now I need to dance with traffic manager to accomplish this.

Yeah, i have worked very little with ACI, but it does not seem like something i want, but i might be forced to.
This blok got me to search for alternatives, just a bit harder :P
https://blog.tech-fellow.net/2021/01/21/building-real-time-public-transport-tracking-system-on-azure-part-6-packing-everything-up/

Just took a spin of Container App to run our gRPC service. Probably doing something wrong :D

upstream connect error or disconnect/reset before headers. reset reason: connection termination

I also was unable to get grpc running on the public app url. I opened an issue asking to clarify how grpc is supported in container apps here microsoft/azure-container-apps#38

UPDATE: Good news, was able to get GRPC running on container apps. See the linked issue for details.

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I think this is still something that should be supported by non-container projects. No one is saying anything because there's not much more to say. It should just be done.

We can keep this open to track it.

It's been 3 years since the ticket was opened and yet it's still not supported? :(

I've given up hope on a Windows Update for Windows Server 2019 to fix these http.sys issues in IIS. Can someone from Microsoft just tell us that IIS is dead and that trying to host gRPC on Windows (pre-2022) is futile.

Has anyone tried hosting gRPC on IIS on Windows Server 2022?
…
On Sat, Feb 19, 2022 at 10:15 PM Vince Zalamea @.> wrote: I've given up hope on a Windows Update for Windows Server 2019 to fix these http.sys issues in IIS. Can someone from Microsoft just tell us that IIS is dead and that trying to host gRPC on Windows (pre-2022) is futile. — Reply to this email directly, view it on GitHub <#9020 (comment)>, or unsubscribe https://github.com/notifications/unsubscribe-auth/AGE3M253HXMLZZ4TQ76VDWTU4BMGLANCNFSM4HDHMSDA . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub. You are receiving this because you commented.Message ID: @.>

Yes, we are doing it for the last few months in production and its works.