I'm trying to have 100 Android devices that display text string based on a server parameter. When the server has the text changed from "Hello World" to "Everything Changed" I want all 100 android devices to update simultaneously and ideally instantly as soon as the change happens.
It runs on an isolated LAN so C2DM isn't feasible and polling every second seems rather traffic heavy (especially if there are 1000 devices later). Are there any recommendations on how to move from polling to pushing or at least making this scalable?
I've been considering just keeping the connection open and the server returns content only when it changes but worried about timeout issues and PHP's capability of handling 100's of concurrent connections... Any pointers or advice to try?