TopicLookup memory leak

[IrvinDominin]

We are using SignalR version 2.4.2.

We are facing an incremental memory usage of each node of our SignalR application, typically it cause an OOM error and crash. We can't find if there is any object retained. From a dump we are seeing lot of RedisMessageBus-TopicLookup

The clients are some distributed cpp applications used to send messages to specific connected device. On server SignalR we have 6 balanced nodes, sticky session and redis as backplane.

Startup.cs

public void Configuration(IAppBuilder appBuilder)
{
    ...
   appBuilder.UseNinjectMiddleware(CreateKernel);
}

private static IKernel CreateKernel()
{
    Kernel.Bind<IBroadcastManager>().To<BroadcastManager>().InSingletonScope();
    Kernel.Bind<IHubContext>().ToMethod(context =>
            GlobalHost.ConnectionManager.GetHubContext<BrokerHubManager>()
        ).WhenInjectedInto<IBroadcastManager>();
    
    ...
    
    return Kernel;
}

Program.cs

class Program
{
    static void Main(string[] args)
    {
        ...
    }
}

internal class SignalRService : ServiceControl
{
    private IBroadcastManager _broadcaster;
    
    public SignalRService()
    {
        Task.Run(() =>
        {
            WebApp.Start<Startup>(Address);

            _broadcaster = Startup.Kernel.Get<IBroadcastManager>();
            ...

        }).Wait();
        
        _timer = new Timer(MyTimerAsync, null, 0, Convert.ToInt32(Startup.LostDeviceTimer.TotalMilliseconds));
    }
        
    private async void MyTimerAsync(object stateInfo)
    {
        _broadcaster.XXX();
        
        ...
    }
}

BrokerHubManager.cs

public class BrokerHubManager : Hub
{   
    public BrokerHubManager()
    {
        ...
    }
}

BroadcastManager.cs

public class BroadcastManager : IBroadcastManager
{
    private IHubContext _context;
    
    private BroadcastManager(IHubContext context)
    {
        _context = context;
    }
}

We have a timer that each 15 minutes takes all the not alive devices and disconnect them:

        private async void HeartbeatDevicesAsync(object stateInfo)
        {

            try
            {
                if (Startup.TraceMode) BrokerLogger.LogInfo("Timer Heartbeat device - Checking connections ...");
                var heartBeat = GlobalHost.DependencyResolver.Resolve<ITransportHeartbeat>();

                //SignalR connections
                var connectionList = heartBeat?.GetConnections();
                foreach (var connection in connectionList)
                {
                    if (!connection.IsAlive)
                    {
                        if (Startup.TraceMode) BrokerLogger.LogWarn($"SignalR Graceful disconnection Id -> {connection.ConnectionId}");

                        await connection.Disconnect();
                    }
                }
            }
            catch (Exception e)
            {

                if (Startup.TraceMode) BrokerLogger.LogErr(e.ToString());
            }
            if (Startup.TraceMode) BrokerLogger.LogInfo($"Timer Heartbeat is sleeping for  {Startup.HeartbeatDevicesTimer.TotalSeconds} seconds ...");
        }

Expected behavior

We need that memory goes up and down accordingly to the live connestions, actually is growing day by day.

Actual behavior

Here is some informations took from DotMemory when the applications "starts to grow"

[hoedinie]

Has there been any solution? We currently have similar issues where the Memory overflows with Retention path of Microsoft.AspNet.SignalR.Messaging.Topic

[IrvinDominin]

Hi @hoedinie sadly no, no news from the team (I try to poke @davidfowl if can point us); we are considering switching to Core, but it's a big project and it's cost expensive

[noxiaz]

Nothing new?

[IrvinDominin]

Nothing new?

Currently nothing; I hope someone from Microsoft can help us, but nothing here

[noxiaz]

Nothing new?

Currently nothing; I hope someone from Microsoft can help us, but nothing here

It sucks, i need to terminate the program every 4 hour as its consuming a high amount of memory very fast.