Can you use fractional vCPUs with GAE Flexible Environment?

I'm transitioning an application from GCE to GAE Flexible. It's currently running in a g1-small instance which is plenty for my needs, however when I try to specify a g1-small instance in my app.yaml:

resources:
  cpu: 0.5
  memory_gb: 1.7

I can deploy but there's no indication that a smaller instance is actually being used.

After deploying, there's no indication that my app is running with the smaller instance size.

How can I use fractional vCPUs with the flexible environment? Thanks!

Solution

There is no way to use shared (fractional) CPUs on App Engine Flexible at the moment; The number of CPUs you specify must be an even number between 2 and 96. (If it's not the default value of 1)

There is an open feature request for shared CPU instances on the Public Issue Tracker which you can star or add to in order to show your interest in that feature.

Note that there is also no existing feature that lets you directly specify App Engine Standard instance classes or Compute Engine machine types to use in App Engine Flexible.