Nginx和Node.js服务器-多个任务

Question

UPDATE

I have a few questions about the combination of Nginx and Nodejs.

I've used Nodejs to create my server and now I'm facing with an issue about catching the server for an actions (writing, removing and etc..). We are using Redis to lock the server when there are requests to the server, for example if a new user is doing a sign up action all the rest of the requests are waiting until the process is done, or if there is another process (longer one) all the other requests will wait longer.

We thought about creating a Load balancer (using Nginx) that will check if the server is locked, and if the server is locked it will open a new task and won't wait until the first process is done.

I used this tutorial and created a dummy server, then I've struggled with the idea of do this functionality of opening a new ports.

I'm new with load balancing implementation and I will be happy to hear your thoughts and help.

Thank you.

Answer 1

The gist of it is that your server needs to not crash if more than one connection attempt are made to it. Even if you use NGINX as a load balancer and have five different instances of your server running...what happens when six clients try to access your app at once?

I think you are thinking about load balancers slightly wrong. There are different load balancing methods, but the simplest one to think about is "round robin" in which each connection gets forwarded to the next server in the list (the rest are just more robust and complicated versions of this one). When there are no more servers to forward to, the next connection gets forwarded to the first server again (whether or not it is done with its last connection) and the circle starts over. Thus, load balancers aren't supposed to manage "unique connections" from clients...they are supposed to distribute connections among servers.

Your server doesn't necessarily need to accept connections and handle them all at once. But it needs to at least allow connections to queue up without crashing, and then accept and deal with each one by one.

You can go the route you are discussing. That is, you can fire up a unique instance of your server...via Heroku or other...for every single connection that is made to your app. But this is not efficient and will ultimately create more work for you in trying to architect a system that can do that well. Why not just fix your server?