way to inform rev apps to get something from web server

[Brian Yennie]

Jim,

Are you sure that simple polling is really too "bandwidth wasteful"  
for your application? You can make a lot of HTTP requests for a tiny  
file without coming close to the bandwidth needed for even small media  
files. A single dedicated web server should be able to service many  
thousands of requests per second. If each client was checking every 5  
minutes (= 300 seconds), you could quite possibly scale to over a  
million clients talking to just 1 basic web server.

If you are serving media files from the same server, I would first  
look at that as the bottleneck. Those could eat up your server  
resources much faster than the polling. One simple solution would be  
moving your media files to a service such as Amazon S3, and then have  
the "gateway" server just service polling requests.

When you say "data" -- are these static files, or something that needs  
server-side scripts to return?

Generally speaking, there is no general solution. You need to define  
the actual requirements -- how frequent is the polling, how many users  
must you support, what is your budget, what kind of data are you  
serving, etc.

HTH

> Here is what I want to do:
>
> Lets say I have a large number of rev apps that will go to a web  
> server and grab some data/image when told to do so (when given a  
> signal to do so).
>
> I could have these apps poll a text file or something on a web  
> server every so many minutes but I want a less 'bandwidth wasteful'   
> way to inform these apps to act.
>
> What is the best way to do this? UDP? TCP server/client? Something  
> else?
> What obstacles might I encounter?
>
>
> sim