Engine development, and interacting with a Google Talk user will be one of those
examples. Let's take a quick look at how the XMPP quota calculates these metrics.
XMPP API Calls : The total number of times the applications accesses
the XMPP service.
XMPP Data Sent : The amount of data sent by the XMPP service. As
with the other data metrics, this counts toward your Outgoing
XMPP Recipients Messaged : Each time you communicate with a
recipient over the XMPP service, App Engine subtracts from this
XMPP Invitations Sent : To initiate a chat with another party you may
need to send invitations. This metric represents the total number of
invitations sent by the application.
To manipulate image data, you can use App Engine's dedicated Images service,
which allows you to resize, rotate, flip, and crop images. You can use the Images
service to construct a composite of multiple images and convert images from one
format to another. The service also provides a predefined algorithm for photo
enhancements. These Images service features count against the following quota. The
exact measurements are listed in Table 2-8.
Table 2-8. App Engine Quotas for the Images Service
4,800 calls / min
Data Sent to API
5MB / min
400MB / min
28MB / min
300MB / min
transforms / min