You should look into writing a transport action. Such an action can receive a request and distribute it to the nodes of an index, or even to all cluster nodes (which is called a broadcast action).
If the analyzer configuration request is a file, you can - beside indexing the data - either save the file to the path.logs directory (which is writable) or you could store the file into the cluster state (which I do not recommend). Usually files are not useful at all at server side, the sync and update management of them is prone to errors. I recommend keeping the file at client side, and execute the action immediately in memory as necessary. If files get lost, just repeat the client action to configure the analyzer.