I would write the content to file every 30 seconds on an lightweight webserver (not an app server) or a CDN. Point all the clients to the file and then have you

I would write the content to file every 30 seconds on an lightweight webserver (not an app server) or a CDN. Point all the clients to the file and then have your application write the file say every 28 seconds. Get the high load out of the application server and cache the data on the edge. It will be far more performant and it is much simpler to scale the edge.