Google App Engine Channel API quotas list?

So the docs say: Messages are limited to 32K开发者_Python百科. That's actually all it says.

• How many channels can I open?
• How many messages can I send per day per channel?
• Which is the max size of a message?

(The numbers provided below were current as of May 20, 2011):

"How many channels can I open?"

Google is not listing a total maximum open, just a maximum creation rate: Free: 8,640/day (6/min) & Paid: 86,400/day (60/min) - but they also make clear that if you need to exceed these maximums they can accommodate. [ see: http://code.google.com/appengine/docs/quotas.html#Channel ]

"What is the maximum size of a message?"

The API lists that the message payload must be smaller then 32k when UTF-8 encoded. [ see: http://code.google.com/appengine/docs/quotas.html#Channel ]

"How many messages can I send per day per channel?"

Google does not specify a per channel message limit, but does specify an outgoing bandwidth limit. Given the maximum message size is 32k, then with the daily outgoing bandwidth limit of 1GB, you can send at least 31,250 messages (1GB total / 32k max message size) without billing enabled and 450,000,000 (14,400 GB / 32K) with billing enabled.

If you aren't sending the maximum size messages, the actual number can be greater - and of course, as mentioned above Google provides a mechanism to make arrangements for larger amounts.

• You can see the exact quotas for your app's use of the Channel API in the admin console under 'quotas'. Enabling billing will increase them, and if your billing enabled app runs out, you can ask us to increase the quota further.
• 32k.