I wrote a program to send mails from GAE. It can be run in two ways:-
- as a http request
- as a scheduled cron job (by writing job desc. in cron.yaml)
Requests per second for the latter case is almost half the former.

Why could be the possible reason for this?
As you can see, there are 2 request instead of one when using HTTP requests. All modern browsers attempt to retrieve the favicon.ico file from the server, and, even if it does not exist, it is counted in the graph.