Some weeks ago my app on App Engine just started to increase the number of idle instances to an unreasonable high amount, even when there is close to zero traffic. This of course impacts my bill which is skyrocketing.
My app is simple Node.js application serving a GraphQL API that connects to my CloudSQL database.
Why are all these idle instances being started?
My app.yaml:
runtime: nodejs12
service: default
handlers:
- url: /.*
script: auto
secure: always
redirect_http_response_code: 301
automatic_scaling:
max_idle_instances: 1
Screenshot of monitoring:
Update after 24 hours:
I followed @Nebulastic suggestions, number 2 and 4, but it did not make any difference. So in frustration I disabled the entire Google App Engine (App Engine > Settings > Disable application) and left it off for 10 minutes and confirmed in the monitoring dashboard that everything was dead (sorry, users!).
After 10 minutes I enabled App Engine again and it booted only 1 instance. I've been monitoring it closely since and it seems (finally) to be good now. And now after the restart it also adheres to the "min" and "max" idle instances configuration - the suggestion from @Nebulastic. Thanks!
Screenshots: