Why I got over quota error ? google app engine

Question

I have a project in google app engine, I have backend-module which I use to run long backend process. this's the configuration at backend-module.yaml file:

module: backend-module
version: one
runtime: python27
api_version: 1
threadsafe: yes
instance_class: B8
basic_scaling:
  max_instances: 11
  idle_timeout: 10m 

but when I run long running process I go this error : This application is temporarily over its serving quota. Please try again later.

EDIT: I want to resize many images that saved in my cloud storage.

the code run when I send http request to a specified url.

so I used a module (basic scalling) to run this long process....

the billing is enabled in my app, so I thought I could run backends as much as I want. right ?

BTW: my app doesn't crash, the automatic modules are still working good !

Answer 1

You also could have used more than 50% of your quota before half day, so app engine anticipated that you'd go over and cut you off right away. Here's the message you can read in your console in the "quota details" page, which explains it:

If your application exceeds 50% of any particular quota halfway through the day, it may exceed the quota before the day is over.

In addition to enabling billing, you have to increase the budget.

Free quotas are different depending on the modules you're using, which explains why your code works in the default module and not in a backend module (there's less free quota for backend). Details here.

Answer 2

It means that your application's daily quota is over. You view your application quota details from App engine admin console.

For More info about appengine quota: https://cloud.google.com/appengine/docs/quotas