Firebase has announced in September 2021 that it is possible now to configure its cloud function autoscaling in a way, so that a certain number of instances will always be running (https://firebase.google.com/docs/functions/manage-functions#min-max-instances).
I have tried to set this up, but I can not get it to work: At first I have set the number of minimum instances in Google Cloud Console: Cloud Console Screenshot After doing this I expected that one instance for that cloud function would run at any time. The metrics of that function indicate that it instances were still scaled down to 0: Cloud functions "Active Instances Metric"
So to me it looks a bit as if my setting is ignored here. Am I missing anything? Google Cloud Console shows me that the number of minimum instances has been set to 1 so it seems to know about it but to ignore it. Is this feature only available in certain regions?
I have also tried to set the number of minimum instances using the Firebase SDK for Cloud Functions (https://www.npmjs.com/package/firebase-functions). This gave me the same result, my setting is still ignored.
According to the Documentation, the Active Instances metrics shows the number of instances that are currently handling the request.
As stated in the Documentation :
Cloud Functions scales by creating new instances of your function. Each of these instances can handle only one request at a time, so large spikes in request volume often causes longer wait times as new instances are created to handle the demand.
Because functions are stateless, your function sometimes initializes the execution environment from scratch, which is called a cold start. Cold starts can take significant amounts of time to complete, so we recommend setting a minimum number of Cloud Functions instances if your application is latency-sensitive.
You can also refer to the Stackoverflow thread where it has been mentioned that
Setting up minInstances does not mean that there will always be that much number of Active Instances. Minimum instances are kept running idle (without CPU > allocated), so are not counted in Active Instances.
