Many people seem to be complaining about the shift from CPU-hour to instance-hour pricing. They don't seem to get that it's more or less the same thing: dynamic instances can handle "a small number" of concurrent requests.
So the GAE team has set the incentives correctly, to reward apps that work well with concurrency.
The current free quota is 6.5 CPU hours, and the upcoming free quota seems to be 24 instance hours. I know which I prefer.
"We have added a few restrictions to the Mail API to improve the reliability and reputation of the service for all applications. First, emails must be sent from email accounts managed by Google (either Gmail, or a domain signed up for Google Apps). Second, we’ve reduced the number of free recipients per day from 2000 to 100 for newly created applications."
Rob Pike is giving (or has given already?) a talk on writing web apps in Go at Google I/O today, it is not livecasted, but the video should be up tomorrow.
There were a lot of complaints from people that had infrequently used (new) web apps, and so there would be a substantial delay to spin up an instance when the app did get hit. This makes your site seem "slow" even though it really isn't, which is a big problem if you are trying to build some momentum, or show off your site to potential investors. People were resorting to some less than ideal ways for keeping their instances warm, more information on the app engine for java group: http://code.google.com/p/googleappengine/issues/detail?id=24...
I take it that you're talking about the new Backends:
Backends are special App Engine instances that have no request deadlines, higher memory and CPU limits, and persistent state across requests. They are started automatically by App Engine and can run continously for long periods. Each backend instance has a unique URL to use for requests, and you can load-balance requests across multiple instances.
Backends seem overpriced to me; their default backend is a long-lasting process running at 1.2Ghz allowed to use 256MB of RAM and it's priced $0.16/hour ($115/month).
They can shutdown/restart/relocate your backend whenever they want so what they suggest to keep your service live is "Configuring more backend instances than are normally required to handle your traffic patterns" (yeah that's at least another $115/month fee).
At linode that kind of money will give you 4G of ram, cpu power in the same ball park and loads of storage and transfer.
It seems that Backends - and the GAE in general - makes most sense when you view the system as a whole, and work with systems of a certain size. Tasks goes in to queues and backends are started and stopped as needed - stuff like that. If all you need is to serve a long running process, linode and the like is more economical.
So the GAE team has set the incentives correctly, to reward apps that work well with concurrency.
The current free quota is 6.5 CPU hours, and the upcoming free quota seems to be 24 instance hours. I know which I prefer.