I am working on a project that involves gps data collection from many users (say 1000) every second (while they move). I am planning on using a dedicated database instance on EC2 with the mysql persistent block storage and run a ruby on rails application with nginx frontend. 
I haven't worked on such data collection application before. Am I missing something here?

I will have a another instance which will act as application server and use the data from the same EBS.
If anybody has dealt with such a system before, Any advise would be much appreciated?