Question

I currently keep my users in a table called OnlineUsers. When a person connects or disconnects it adds the userid and his connectionid to the table, but for some reason (i believe when multiple browser windows are open) the Disconnect function does not fire sometimes, leaving users in the table and making them appear “online” when they really aren’t. Has anyone ran into this problem before and what would be a good way to fix this issue?

UPDATE** (sorry about not putting code, I should have done it in the first place)

Here are my db functions to add and remove from the table:

    public bool ConnectUser(Guid UserId, String ConnectionId)
            {
                if (!Ent.OnlineUsers.Any(x => x.UserId == UserId && x.ConnectionId == ConnectionId))
                {
                    Ent.OnlineUsers.AddObject(new OnlineUser { UserId = UserId, ConnectionId = ConnectionId });
                    Ent.SaveChanges();
                    return true;
                }
                else
                    return false;
            }
            public void DisconnectUser(Guid UserId, String ConnectionId)
            {
                if (Ent.OnlineUsers.Any(x => x.UserId == UserId && x.ConnectionId == ConnectionId))
                {
                    Ent.OnlineUsers.DeleteObject(Ent.OnlineUsers.First(x => x.UserId == UserId && x.ConnectionId == ConnectionId));
                    Ent.SaveChanges();
                }
            }

Here is my hub class connect and disconnect task:

 public Task Disconnect()
        {

            disconnectUser();                
            return null;
        }
        public Task Reconnect(IEnumerable<string> connections)
        {
            connectUser();                
            return null;
        }
        public Task Connect()
        {
            connectUser();               
            return null;
        }
private void connectUser()
        {
            if (onlineUserRepository.ConnectUser(MainProfile.UserId, Context.ConnectionId))
            {
                Groups.Add(Context.ConnectionId, Convert.ToString(MainProfile.ChatId));
            }
        }
        private void disconnectUser()
        {
            onlineUserRepository.DisconnectUser(MainProfile.UserId, Context.ConnectionId);
            Groups.Remove(Context.ConnectionId, Convert.ToString(MainProfile.ChatId));
        }

I have checked that I am on the latest version of signalR (0.5.3) and this seems to happen when I have multiple browser windows open and I close them all at once, the users will get stuck in the database.

In case this is needed, this is my Connection Id Generator class:

public class MyConnectionFactory : IConnectionIdGenerator
    {
        public string GenerateConnectionId(IRequest request)
        {            
            if (request.Cookies["srconnectionid"] != null)
            {
                return request.Cookies["srconnectionid"].ToString();
            }

            return Guid.NewGuid().ToString();
        }
    }

Answer 1

I think your connection factory is indeed the problem. If the case that you do not find a cookie, you go ahead and generate a new guid, but by that time it’s already too late.

My understanding is that the connection id is established by the client (the client side hub) during initialization and cannot be changed at the server; it can only be read. In effect when you are returning a new Guid when you don’t find the cookie you are changing the client id.

In my connection factory if the cookie is not found I throw. In the controller action that opens the page that is using signalr I make sure the cookie is planted.

Here is my connection factory:

public class ConnectionFactory : IConnectionIdGenerator
{
    public string GenerateConnectionId(IRequest request)
    {
        if (request.Cookies["UserGuid"] != null)
            return request.Cookies["UserGuid"].Value;

        throw new ApplicationException("No User Id cookie was found on this browser; you must have cookies enabled to enter.");
    }
}