Comparing Google Cloud Run and Compute Engine Costs

May 28, 2020

I like working with containers because they’re portable, repeatable and a heap of other reasons, but that’s not what this post is about. It’s about how run your containers in a cost effective way.

AWS ECS on Fargate is one method to “just deploy” your containers and not have to worry about what they run on. That’s great, but you need to pay for that convenience. I found a blog post that did the calculations (don’t have the link anymore) to compare Fargate to EC2. The result was you were paying about 5x the cost of an EC2 instance for your memory and compute. That’s too much for me.

Today I stumbled across Google Cloud Run while looking for something else. I couldn’t find a blog post that has done the comparison between Cloud Run and Compute Engine so I’m writing it!

Looking at the Compute Engine pricing and the Cloud Run pricing for Sydney, because that’s where I’m running my workload, we get the following numbers:

Cloud run
$0.00002400 per vCPU-second = 0.00002400 * 3600 = 0.0864
$0.00000250 per GiB-Second = 0.00000250 * 3600 = 0.009

GCE
$0.030950 / vCPU hour
$0.004147 / GB hour

So we just need to turn vCPU/GiB seconds into hours by multiplying by 3600:

Cloud run
$0.00002400 * 3600 = 0.0864 per vCPU-hour
$0.00000250 * 3600 = 0.0090 per GiB-hour

Now we compare with GCE:

0.0864 / 0.030950 = 2.791599
0.0090 / 0.004147 = 2.170244

So Cloud Run is 2.8x more expensive for compute and 2.2x more expensive for memory. This doesn’t take into account

free usage for Cloud Run
the fact that you don’t pay when your container isn’t running
the memory used by the OS in GCE, which can’t run containers, but you still need to pay for
your time! You need to setup and maintain a VM and that’s not cheap.

It also doesn’t address the fact that for memory, there appears to be two different units in play: GB and GiB. I couldn’t find enough info in the Google Cloud doco to tell me if that is a typo or they do actually use different units. Assuming it’s correct, we can convert knowing the 1GB = 0.931323GiB.

GCE
$0.004147 per GB hour = 0.004147 * 0.931323 = $0.003862 per GiB hour

Now we compare with Cloud Run:

0.0090 / 0.003862 = 2.330399

The situation is slightly worse at 2.3x the cost for memory.

In any case, I’m very happy with the direction that pricing for this type of service is headed :D