A Node is an endpoint that accepts Jobs from a Controller and returns the output. Nodes are highly simplistic and completely dumb to the outside world. It doesn't even know the Controller exists. It's ownly function is to take incoming Jobs, process them, and return the result on the established socket.
Of course, you can create as many Nodes on a single computer as ports/IPs you have free.
All communication between the Nodes and the Controller is encrypted through SSL. An identical keystore is required for each Node that is going to be used with the Controller. You can generate the keystore (see Getting Started - BlindEyes) on any Node or the Controller and securely transport that keystore to each of the computers that require it. Make sure to update the blindeyes.properties file accordingly.
The Max Active Jobs property of Nodes tells the Controller not to send more Jobs to a Node than the node can concurrently handle as defined in this property. A value of 10 would mean that a Node is set to only handle 10 Jobs at a time. The Jobs will not be queued up in the Node, but they will remain in the Controller available to be assigned to the next appropriate Node.
A Node is only recognized by the Controller if it is Active. By default the Active status is set to True.