How to Anticipate Inter Region Data Transfer Out Charges

[tonymet]

I have a GCE VM & GCS Storage bucket (single-region), both in us-west1.   On october 9 I transferred 6GB from the VM to the bucket, and was charged "Network Inter region Data Transfer Out"  (see below).   The gcs endpoint used was "storage.googleapis.com".   I did not expect an inter-region data transfer fee for writing from GCE us-west1 to GCS us-west1.  This is blocking a larger migration of data.

Questions

• What tools can I use to test an endpoint or IP address for inter-region charges? 
• Will region-specific GCS bucket endpoints (e.g. https://storage.me-us-west1.rep.googleapis.com ) avoid inter-region data transfer fees?
• Why are GCS endpoints DNS using public IP addresses within GCE VM?

What I've tried so far

1. traceroute to both endpoints, results are inconclusive . number of hops are similar
2. "dig" of endpoints results in different IP addresses. Unclear how that affects billing
3. Google Cloud metrics "bytes_sent" shows the volume of bytes sent, but it does not show which bytes are billed for inter-region transfer
4. I've used the Network Management Connectivity tester to identify routing, but both global and region-specific endpoints show the same routing. 

Billing Info Oct 9, 2024

Network Inter Region Data Transfer Out from Americas to Americas
C8EA-1A86-3D28 6.29 gibibyte $0.11 

Related Posts

• Re: How to check cross-region traffic volume - 202... - Google Cloud Community

[FrancoGP]

Hi @tonymet ,

Welcome to Google Cloud Community!

From my understanding and it's not something restricted only to GCP service endpoints by default are using public routing even if it's from a GC resource, so that outbound request will be there unless, depending on your architecture you enable private google access.

Use a Regional Endpoint is a good idea, would redirect traffic with no other hops. 

Although won't fully fulfill your desires the network topology tool from the network intelligence module in gc with the egress filter may bring you a nifty visualization of the regions interconnecting with your VM and from there take your conclusions

[tonymet · Accepted solution]

thanks for the help. I did a more empirical experiment on the 2 endpoints and found that https://storage.us-west1.rep.googleapis.com/ bills as "intra-zone data transfer out" and storage.googleapis.com bills as one of "inter-zone" or "inter-region" data transfer out (with a cost)

https://forum.rclone.org/t/gcs-use-region-specific-endpoints-to-avoid-inter-region-transfer-fees-of-...

[mz_cloudacetw]

hi tonymet,

thanks for your information, i have a question further that are you still get bill after enable private google access in your VPC?

thanks in advance!!

[tonymet]

I'm not using private access in VPC.  The test variants were both public GCS endpoints.

[brangel]

My guess here!

Transfer Out will be charged as the same using Private Google Access (PGA), once the Resource to be reached out is located in another Region from the Source.

• Data transfer to Memorystore for Redis, Filestore, Cloud SQL, and Google Kubernetes Engine within the same region is priced the same as VM-to-VM traffic

https://cloud.google.com/vpc/network-pricing

[tonymet]

this billing issue was on GCS , which will route outside of the region, even if the bucket & GCE region are in the same region.