I have a web app with Client running on Blazor Server. I have set a custom Blazor reconnect modal (<div id="components-reconnect-modal"...) as the documentation says here - Microsoft Docs
Also I have these settings for SignalR and Blazor circuits:
services.AddServerSideBlazor
(options =>
{
options.DisconnectedCircuitMaxRetained = 100;
options.DisconnectedCircuitRetentionPeriod = TimeSpan.FromMinutes(5);
options.JSInteropDefaultCallTimeout = TimeSpan.FromMinutes(1);
options.MaxBufferedUnacknowledgedRenderBatches = 10;
})
.AddHubOptions(options =>
{
options.ClientTimeoutInterval = TimeSpan.FromSeconds(30);
options.EnableDetailedErrors = false;
options.HandshakeTimeout = TimeSpan.FromSeconds(15);
options.KeepAliveInterval = TimeSpan.FromSeconds(15);
options.MaximumReceiveMessageSize = 32 * 1024;
options.StreamBufferCapacity = 10;
});
But I have an annoying problem - Whenever the app is open in a browser tab and stays still with nobody using it it disconnects. It happens very inconsistently and I can't locate the configuration for these custom time periods but I need to enlarge them. Example:
Initialy loaded the app at 11:34:24AM
Leave it like that for a while
In the Console: "Information: Connection disconnected." at 11:55:48AM and my reconnect-modal appears.
How can I enlarge the lifetime of the connection so that it is always bigger than my session timeout. I checked the Private Memory Limit of my app pool but it is unlimited. It happens really inconsistently with the same steps to reproduce. Test 1 - 16 mins 20 sec; Test 2 - 21 mins 58 sec; Test 3 - 34 mins 56 sec...and then after iisreset...Test 4 - 6 mins 28 sec
Please help.
Apparently this is by design. Once the client is idle for some time it essentially stops sending pings to the server. Then the server only knows tha the client has disconnected and drops the details to allow for resource reuse. You can edit the times and count of “inactive” connections as you have done in the CircuitOptions, but at some point if the client is idle it will disconnect.
have a look at:
https://learn.microsoft.com/en-us/aspnet/core/blazor/state-management?view=aspnetcore-3.1&pivots=server
I think that you can go around this error by using this code in _Host.cshtml:
<script>
Blazor.start().then(() => {
Blazor.defaultReconnectionHandler._reconnectionDisplay = {
show: () => {},
update: (d) => {},
rejected: (d) => document.location.reload()
};
});
</script>
Please read also about Modify the reconnection handler (Blazor Server)
See also this answer
Are you hosting on IIS?
Is the default IIS App Pool recycling set to 20 mins of Idle?
You could try and set this to 0.
Related
I am working on a dot net core web application and i want to get the user idle time. if the user is not working / interacting with the application more than 20 minutes i want to throw a message "User is idle for 20 min". how do i achieve this?
I would suggest to use javascript solution since we need to track client side user interaction.
ex for 5 seconds user idle.
let idletime;
const resetIdleTime = ()=> {
console.log('Clearing out the idle time');
console.log(new Date(Date.now()).toISOString());
clearTimeout(idletime);
idletime = setTimeout(trackIdleTime, 5000);
}
const trackIdleTime = ()=> {
console.log(new Date(Date.now()).toISOString());
console.log('Do required things when session is idle');
}
resetIdleTime();
document.onmousemove = resetIdleTime;
document.onkeypress = resetIdleTime;
my blazor app seems to work but im trying to understand why I'm getting a 400error as seen in the screenshot.
Who can give me a HINT for what Blazor needs technically the "disconnect" ?
SCREENSHOT-disconnect
I'm running everything on a NGINX webserver.
thx Fabio
That call happens here in the code on the window unload event and is used to tell the signalr server that you are disconnecting.
If you are seeing a lot of these it may be that your proxy is not configured correctly for websocket connections.
window.addEventListener(
'unload',
() => {
const data = new FormData();
const circuitId = circuit.circuitId!;
data.append('circuitId', circuitId);
navigator.sendBeacon('_blazor/disconnect', data);
},
false
);
There's a bug reported for this issue here:
https://github.com/dotnet/aspnetcore/issues/30316
Blazor.server.js not respecting configureSignalR builder defined
url/path for disconnnects
As a work-around, I added this to Startup.cs in the Configure method:
var rewriteOptions = new RewriteOptions();
rewriteOptions.AddRewrite("_blazor/disconnect", "/_blazor/disconnect", skipRemainingRules: true);
app.UseRewriter(rewriteOptions);
I created dot net core SignalR client using https://learn.microsoft.com/en-us/aspnet/signalr/overview/getting-started/tutorial-getting-started-with-signalr
Using StartAsync connection takes more than 1 second.
That is too long.
How can we reduce start time? Any parameters to tweak?
Thanks for response and the rectified link.
Solution is using ASP.NetCore and transport is configured to use WebSocket ONLY.
Server side (Startup/ Configure)
app.UseEndpoints(endpoints =>
{
endpoints.MapHub<LiveHub>("/signalr/livehub", options =>
{
options.Transports = HttpTransportType.WebSockets;
});
});
Console Client application was built as per:
https://github.com/aspnet/AspNetCore.Docs/tree/master/aspnetcore/signalr/dotnet-client/sample/SignalRChatClient
Under Client
connection = new HubConnectionBuilder()
.WithUrl("http://localhost:xxxx/signalr/livehub", options =>
{
options.SkipNegotiation = true;
options.Transports = HttpTransportType.WebSockets;
})
.Build();
Time for code execution was calculated on client, on
await connection.StartAsync();
With multiple test cases, average connection time hovers around 900msec to 1200 msec.
This is a very long time.
I have two applications that I need to synchronise. One of them will receive data from users and the other will display the data. Both applications will work on different servers. They could be disconnected at some times and they need to continue working until reconnect, so I will replicate the data from the first application on the second application.
On Meteor documentation I found DDP.connect(url)but I'm not sure how to use it. I found many questions and examples connecting non Meteor applications with Meteor using DDP, but nothing about connecting two Meteor applications.
My first approach was something like this:
Application 1
Items = new Meteor.Collection('items');
Items.insert({name: 'item 1'});
if (Meteor.isServer) {
Meteor.publish('items', function() {
return Items.find();
});
}
Application 2
Items = new Meteor.Collection('items')
if (Meteor.isServer) {
var remote = DDP.connect('http://server1.com/);
remote.onReconnect = function() {
remote.subscribe('items');
var items = Items.find();
console.log(items.count()); // expected to be 1 but get 0
}
}
On the second application, how can I get the items from the first application?
I got a clue from this question How to properly use Meteor.connect() to connect with another Meteor server. I missed it because it was about the old Meteor.connect() that changed to DDP.connect().
This worked on client and server
var remote = DDP.connect('http://server1.com/');
Items = new Meteor.Collection('items', remote);
remote.subscribe('items', function() {
var items = Items.find();
console.log(items.count()); // get 1
});
Now I can watch for changes in application 1 from application 2 using Items.find().observe()
Warning
There is a bug on Meteor that will stop the connection between applications:
https://github.com/meteor/meteor/issues/1543
DDP between two servers doesn't reconnect
Update
The bug was solved
Update 2
This is a sample project tested with Meteor 0.6.6.2 https://github.com/camilosw/ddp-servers-test
I implemented a graceful stop to our node.js server. Basically something like this:
var shutDown = function () {
server.on('close', function () {
console.log('Server ' + process.pid + ' closed.');
process.exit();
});
console.log('Shutting down ' + process.pid + '...');
server.close();
}
However, when I close the server like this, I get a Error: socket hang up error in my continuous requests.
I thought that server.close() would make the server stop listening and accepting new requests, but keep processing all pending/open requests. However, that should result in an Error: connect ECONNREFUSED.
What am I doing wrong?
Additional info: The server consists of a master and three forked children/workers. However, the master is not listening or binding to a port, only the children are, and they are shut down as stated above.
Looking at the docs, it sounds like server.close() only stops new connections from coming in, so I'm pretty sure the error is with the already-open connections.
Maybe your shutDown() can check server.connections and wait until there are no more?
var shutDown = function(){
if(server.connections) return setTimeout(shutDown, 1000);
// Your shutDown code here
}
Slightly uglier (and much less scalable), but without the wait: you can keep track of connections as they occur and close them yourself
server.on('connection', function(e){
// Keep track of e.connection in a list.
// You'll want to remove e.connection
// from the list if it closes on its own
}
var shutDown = function(){
// Close all remaining connections in the list
// Your shutDown code here
}