I am planning to use Meteor for a realtime logging application for various My requirement is pretty simple, I will pass a log Message as request Parameter ( POST Or GET) f
As things stand, there isn't support for server side routing or specific actions on the server side when URLs are hit. So it's not easy to do what you want. Here are some suggestions.
You can probably achieve what you want by borrowing techniques that are used by the oauth2 package on the auth branch: https://github.com/meteor/meteor/blob/auth/packages/accounts-oauth2-helper/oauth2_server.js#L100-109
However this isn't really supported so I'm not certain it's a good idea.
Your other applications could actually update the collections using DDP. This is probably easier than it sounds.
You could use an intermediate application which accepts POST/GET requests and talks to your meteor server using DDP. This is probably the technically easiest thing to do.