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.
Probably good news for SendGrid.
This could be a cool opportunity to do so. Does anyone have any resources for writing Go webapps?
This fixed the other half (long running processes).
None of my AppEngine apps ever had any problem with 'cold' startup speed, and now with Go startup speed will be even less of an issue.
I believe they are more like Tasks on Steroids than a way of having something like a little persistant VPS for your app.
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.
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).
But yes, they are expensive.