APIs for components to persist state across circuits manually

[javiercn]

This is tracking the next piece of #27576. (Pointing out that this issue has additional 20 reactions)

We want to provide the ability for circuits to be paused and stored in "permanent" storage to make possible certain scenarios:

• Migrating circuits across servers.
• Freeing up resources when the circuits become idle.
• Enabling reconnection to an existing session even after the circuit has been discarded.

Our goal is that circuits stored this way can be restored in a similar fashion as when they are restored after prerendering.

Important note

This is not a suggestion that circuits could automatically be persisted in their entirety. In general that's not possible as much of the system state is not even serializable, and we don't require developers only to work with serializable data. Rather, what we may be able to do here is provide some APIs by which you can load and save state in your components, so that if a user loses their circuit, we can reload that manually-saved state in the new circuit. It could not be a global or automatic thing.

[ghost]

Thanks for contacting us.
We're moving this issue to the Next sprint planning milestone for future evaluation / consideration. We will evaluate the request when we are planning the work for the next milestone. To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[ghost]

We've moved this issue to the Backlog milestone. This means that it is not going to be worked on for the coming release. We will reassess the backlog following the current release and consider this item at that time. To learn more about our issue management process and to have better expectation regarding different types of issues you can read our Triage Process.

[mkArtakMSFT]

@javiercn should this be closed in favor of the linked issue ? We now have both on the .NET 7 milestone

[nkosi23]

@mkArtakMSFT this ticket is different in that it includes scope explicitly excluded from the other ticket. This ticket will enable both seamless scale out and transparent user-friendly failovers on application update deployments. These are 2 huge features that will finally enable Blazor Server to be used for mid and high-traffic consumer-facing applications.

Thank to this ticket, many people will use Azure for their consumer applications considering the built-in SignalR service and the auto-scaling capabilities. Considering the huge productivity boost provided by Blazor Server I believe this ticket will position Blazor Server and Azure as the leading Web Development stack. With this regard, shipping this in .NET 7 would make the timing perfect.

Generally speaking, this ticket will essentially allow users to treat the servers hosting Blazor Server Apps like stateless servers even though Blazor Server itself would remain stateful. This enables the two aforementioned use cases (which are major ones) and will also simplify a lot of other essential things from an infrastructure management / devops perspective.

This ticket is awaited by a lot of people as can be seen in the popularity of this reddit thread.

[javiercn]

#41791

[Mike-E-angelo]

Thank you @mkArtakMSFT, @SteveSandersonMS, @danroth27, and team for all your efforts out there! 🙏

Happy Holidays 🎅⛄❄

[kijanawoodard]

@jonrmorgan99

@kijanawoodard Were you able to modify StatefulReconnection to work with Net8 ?

No. Just popped in here to see if there was any development before giving it another shot. At the moment, I don't need to preserve forms, I'm just looking to reload the page after a redeploy rather than getting stuck on the "reload" overlay.

[JoshuaDBruton]

I think Blazor Server is currently unusable because of this. Very much regret building much of our internal application with it; especially with the insane length of time this has taken to resolve, over 3 years with no traction or progress whatsoever.

[KonnectSalon]

Why are we moving this to .net 10?

[danroth27]

Why are we moving this to .net 10?

Hi @KonnectSalon. Unfortunately, we no longer believe we have the time and resources available to deliver this feature for .NET 9. You can see the full roadmap of what we do plan to deliver for .NET 9 here: https://aka.ms/aspnet/roadmap.

[wstaelens]

I think Blazor Server is currently unusable because of this. Very much regret building much of our internal application with it; especially with the insane length of time this has taken to resolve, over 3 years with no traction or progress whatsoever.

this is also our biggest complaints that our customers have, the reloads/disconnects of blazor server.

[JoshuaDBruton]

I think Blazor Server is currently unusable because of this. Very much regret building much of our internal application with it; especially with the insane length of time this has taken to resolve, over 3 years with no traction or progress whatsoever.

this is also our biggest complaints that our customers have, the reloads/disconnects of blazor server.

Now I think it is more of a problem with HTML-over-the-wire and web sockets in general; I think Blazor Server sounded like a good idea but ultimately should not be used in production.

[nbiada]

Now I think it is more of a problem with HTML-over-the-wire and web sockets in general; I think Blazor Server sounded like a good idea but ultimately should not be used in production.

The reload/disconnect situations could be managed via javascript.
When the disconnect happens I intercept the case and redirect the client to the home page.
With the .net 8 version I can create a full static (server rendered) home page, so I need to use the websocket only on forms and complex pages.
Currently I have a lot of Blazor Server website in production and I have no issue from the clients.

[JoshuaDBruton]

The reload/disconnect situations could be managed via javascript. When the disconnect happens I intercept the case and redirect the client to the home page. With the .net 8 version I can create a full static (server rendered) home page, so I need to use the websocket only on forms and complex pages. Currently I have a lot of Blazor Server website in production and I have no issue from the clients.

What is great about traditional MVC applications is that you don't have to worry at all about only using AJAX or whatever only on certain low-traffic pages because the majority of the computation for rendering and animations is always done on the client. I think web sockets basically cap the usage of your application at about ~100 users, which is fine for some small internal applications but is a severe limitation that I think people should be warned about. Even at low usage, I think the cost and user experience will be worse than if the app was developed using more traditional front-end JS; maybe only viable for MVPs or enterprise system where usability is not of high-importance.

[Mike-E-angelo]

In the case of my Blazor application deployed to Azure, I have processed closing in on $15K of volume via Stripe, PayPal, and Coinbase Commerce. This seems pretty production-ready to me. I use Azure SignalR to remove the WebSocket connection challenges. Everything has always been lightning fast and the bottleneck for me is SQL which has been a huge learning lesson for me during this time.

From my experience of actually deploying a Blazor application, everything is pretty awesome and the runtime works incredibly well. It's the socket state/management that has been the sore spot, particularly with iOS devices which disconnect when you simply alt-tab away. 💥😢

[wstaelens]

Now I think it is more of a problem with HTML-over-the-wire and web sockets in general; I think Blazor Server sounded like a good idea but ultimately should not be used in production.

The reload/disconnect situations could be managed via javascript. When the disconnect happens I intercept the case and redirect the client to the home page. With the .net 8 version I can create a full static (server rendered) home page, so I need to use the websocket only on forms and complex pages. Currently I have a lot of Blazor Server website in production and I have no issue from the clients.

care to share your interception logic?

[Mike-E-angelo]

https://www.reddit.com/r/Blazor/comments/1egnkew/a_lot_of_the_features_i_was_looking_forward_to_in/

[yablos]

Hi, real word scenario(even worse) with IOS 17.6:

<InputFile accept="image/*" capture="camera" OnChange.... />

• if you use at blazor-server page simple "camera input", just for capturing photo, the Circuit disconnects ~ about 3s after clicking the input. You are in the middle of the capturing proces(and page at background kills the websocket circuit), so after finishing capturing, the image is "lost". Curcuit is NOT trashed, but disconnected. After returning from capturing, is "resumed", but image is lost(because of the sequence -> click capture->websocket disconected->finished capture->return data to the page= NOGO, we are disconected->resumed connection-> you are back at page, but without "image/data").

If this is new behavior with ios, so capturing images are broken.

• solution? none
• workaround? you have to point user go throught galery/pick file, there take the photo and so on.... uhoh

[SteveSandersonMS]

@yablos That does sound like a problem but is not exactly the same as this issue. Would you mind filing it as a new issue? I can't guarantee this is something Blazor can control but either way having an issue makes it possible to track.

[abratv]

Got my first OutOfMemoryException in development machine with 32 GB memory in blazor interactive server.

While it's a joy to program in Blazor, the architecture is so wrong that its not scalable, how can this be recommended approach to build UI in aspnet core beyond my understanding

User's rendered data in server's in memory is so wrong

Normal Web Application
Ajax call
Minimal api return json
Render it in browser
Server is free to free the memory
Full disconnect

Blazor Interactive Server
Fill data to component
Server hold the memory of data --> per connection/tab
Connection is hold --> also per tab

Of course you have to google why blazor not releasing memory of page that already lose its connection

What is the use case for blazor interactive server? to create fast toy level application?
A page where there is no state? so form maybe work but grid, charts, you know, stuff with lot of data point
in my case it just 100 rows in grid, 100 data point in charts, its already out of memory, 1 user
no way i recommend this technology to my team
no way this going to production

oh yea, just like aspnet webform, silverlight, i need to port this again to whats work
blazor ssr-->this actually just razor page, spa, minimal api

[SteveSandersonMS]

I'd expect an average webserver to handle thousands to tens of thousands of concurrent users in a typical Blazor Server application. If you've been able to out-of-memory with a 100-row grid, something is spectacularly wrong, though unfortunately I can't guess what exactly the cause is.

If you have a simple repro example we'd be happy to take a look and try to understand it. But for any follow-up please file a separate issue so we can keep this one on its original subject.

[nbiada]

Got my first OutOfMemoryException in development machine with 32 GB memory in blazor interactive server.

With 2GB of RAM on an Azure Web App, I actually manage hundreds of thousands of records in many tables with many joins and many views for about 80 concurrent users through a Blazor Server app.
No performance issues related to the Asp.Net Core framework or the Blazor implementation itself.
Some issues on graphs were related to indexes that needed to be created or some graphics performance issues of third-party components.

I have been using Blazor daily in production for 5 years.
I have Blazor Server, Blazor WASM and PWA in production with minimal effort to support them.