Node.js WebSocket

Question

I am working on a nodejs application and the requirement is to send around 10k requests per second per connection. The client application has to open one websocket connection to send these requets and at the server side it has to just receive and send the data to a queue. The number of socket connections at the server side isn't that much, may be around 1k. I have few questions regarding this and any help is greatly appreciated.

• First, is it possible to achieve this setup with a single master process? Since I cannot share the web socket connections with the child processes I need to get the bandwith from master process.
• When I tried benchmarking nodejs ws library, I was only able to send approximately 1k requests per second of 9kb each. How can I increase the throughput?
• Are there any examples on how to achieve max throughput since I can only find posts with how to achieve max connections?

Thanks.

Answer 1

You will eventually need to scale

First, is it possible to achieve this setup with a single master process?

I don't really think its possible to achieve this with a single thread. (you should consider scaling and never design restricting yourself from that option)

Since I cannot share the web socket connections with the child processes I need to get the bandwith from master process.

Im sure you will be happy to know about the existance of socket.io-redis .

With it you will be able to send/receive events (share clients) between multiple instances of your code (processes or servers). Read more : socket.io-redis (Github)

I know you are speaking about ws but maybe its worth the change to socket.io . Image Source Article

Specially knowing you can scale both vertically (increase the number of threads per machine) and horizontally (deploy more "masters" accross more machines) with relative ease. (and I repeat myself : sharing your socket clients & communications accross all instances)

When I tried benchmarking nodejs ws library, I was only able to send approximately 1k requests per second of 9kb each. How can I increase the throughput?

I would suggest trying socket.io + socket.io-redis

1. spawn a master with a number of workers equal to the number of CPU cores. (vertical scaling)
2. deploy your master accross 2 or more machines (horizontal scaling)
3. learn about load-balancing & perform benchmarks.

Are there any examples on how to achieve max throughput since I can only find posts with how to achieve max connections?

You will increase the total throughput if you increase the number of instances communicating with clients. (Horizontal + Vertical Scaling)

• socket.io-redis Application Example (github)
• Using Redis with Node.js and Socket.IO (tutorial)

This might also be an interesting read :

• SocketCluster 100k messages / sec (ycombinator)

• SocketCluster (github)

Hope it helped.