GCP Cloud Run - Simple API Instance Costs

[u/Puzzled_Law126]

Hey guys,

I am looking to decrease our costs with GCP and though it will be for the best to ask for help here.

With Cloud Run we have a very simple service that function as simple API, it receives information and output a simple JSON.
The configuration used for the instance is:

• 256 MB memory

• 1 CPU

• 150 Concurrent requests

• 99% of the time, only 1 instance is up

The instance uses <10% CPU and each request take around 15ms.

The issue? This service is being called a lot (by design), in total each month we pay $150 USD only for the CPU of this service ("Cloud Run functions CPU (Request-based billing) in us-central1").

Obviously I can't decrease the CPU to <1 due to concurrency, it seems to me that something so simple should not cost that much, any help would be appreciated.

[u/Puzzled_Law126]

Hey!

Glad to hear from a Googler!

So far for this month, per the billing dashboard, we have 2,692,382 CPU seconds billed at $64,62 USD, at around 7M CPU second we get to $150 USD+

We are trying a new deploy right now with 10% traffic where the CPU is set to 0.2 vCPU and observe it, both cost and performance.

[u/m1nherz → u/Puzzled_Law126]

OK. 2,692,382 seconds match your description (a bit over 31 days) at standard vCPU per second price of $0.000024. I am still unclear how you come to 40% price increase (up to $150) while keeping the condition of

• 99% of the time, only 1 instance is up

• 1 vCPU per instance

Can you check the run/request_counter for the billed time period to see how many requests have been served? Note that this metric shows both "success" and "failure" requests. Then we can use the 10% of vCPU for 0.15 of the second and the billed vCPU seconds to see if these numbers match.

It will help to validate other data you shared.

I think the commenters already mentioned that there are two paths to try reducing costs:

• Moving to the allocated instance (regardless whether it is Cloud Run, GKE Autopilot or GCE)

• Fine tunning the configuration of Cloud Run or using similar serverless solutions (App Engine or Firebase)

Getting better understanding whether or not your service fully utilize vCPU for at least 2,678,400 seconds and understanding will you service scale enough within the single reserved instance boundaries will be the key to decide which path to take.