How to solve limitations of SignalR in scaleout for backplane
I use ASP.NET MVC and C# .I found SignalR for transfer data in real time,but signalR have some limits.
according to the issue for this :
Using a backplane, the maximum message throughput is lower than it is when clients talk directly to a single server node. That's because the backplane forwards every message to every node, so the backplane can become a bottleneck. Whether this limitation is a problem depends on the application. For example, here are some typical SignalR scenarios:
- Server broadcast (e.g., stock ticker): Backplanes work well for this scenario, because the server controls the rate at which messages are sent.
- Client-to-client (e.g., chat): In this scenario, the backplane might be a bottleneck if the number of messages scales with the number of clients; that is, if the rate of messages grows proportionally as more clients join.
- High-frequency realtime (e.g., real-time games): A backplane is not recommended for this scenario.
My project needs to High-frequency realtime (e.g., real-time games) .
Also I need real time video chat
My scenario :
I have a Master server and multi Slave servers, Clients connect to the Slave servers and ans Slave servers connect to Master server.
Example : Server Slave-1 and server Slave-2 connected to Master server, client-A and client-B connected to Slave-1 an client-C and client-D connected to Slave-2,
client-A send message or data or in live chat with client-D
How I can implement this scenario ?
[Update-1]
If i don't use signalR for that problem, So what should I use?
[Update-2]
In my scenario, the master server acts like a router and Slave server acts like a switch . Clients connected to switch and switch connected to router .if client-A send data packet to client-C, data packet should be send to router and router handle data packet.Over 2000 possible number of Slave servers and the number of users for each server it is over 10,000.
Thanks.
Answer
A backplane will introduce delays in message delivery, which will not work well for low-latency work. If you absolutely must have multiple servers to handle your clients, and you absolutely must have minimal latency, then a backplane is probably not going to work for you.
However, check out this conversation on the ASP forums. The poster is seeing average latencies of around 25ms for 60,000 messages per second to 3,000 connected clients on one server.
As is often the case, the trade-off here is between latency and complexity. The optimal solution is for messages to be routed only to the server(s) containing the target client(s). To achieve this you need a way to track every client connection, deal with reconnects to different servers, etc. You can probably solve this with a few tens of hours of hard slog programming, but in doing so you're going to break most of what makes SignalR useful.
For alternatives, the first that comes to mind is ZeroMQ. A bit more work, especially if your clients are browser based, but low latency and high throughput are project goals for ZeroMQ. You'll need to handle scale-out yourself though... and you're back to tracking connection points across multiple servers and reconnects.
If neither of these solves your problems, then you might have to look at changing your architecture. One common method for MMOs is to have related clients connect to the same servers to reduce inter-server communication requirements. Clients who legitimately need to communicate real-time data are put together on a single server which doesn't have to worry about back-plane issues. This server then communicates back to the 'Master' server only what is required to maintain world state and so on.
Plan your architecture to reduce the problems before they start... but don't spend weeks working on something that might not be necessary. Do some tests on SignalR and see what effect the backplane actually has on latency before you dive into the abyss.