How Much Google Cloud Platform Charge You on F1-Mirco VM

AWS offers a 1-year-free trial. The trial is more than enough to get your feet wet, including 750 hours/month of a small 1 CPU/1GB RAM instance with 30GB disk storage, 750 hours/month of a similarly-sized managed database instance (e.g. MySQL), and 5GB of cloud storage (enough for a small web server running constantly for a year).

Google Cloud offers a 12 months, $300 credit trial, and a Free Tier that isn’t time-limited. That means, you can get an instance with 1 shared  vCPU/0.6GB RAM with 30GB disk storage and 5GB cloud storage, all for free. You should be able to run a small website for free, forever if Google keeps this policy. 

Notes: From Aug 1 2021, GCP introduced a new E2-micro VM for free tier, which has 0.25 vCPU (which burst to 2 vCPU periodically) and 1 GB of RAM.

In fact, there are always some other small charges coming based on my testing, especially from spiked cpu and egree traffic. I have been using GCP VM instance for a small site for a while. It was not been charged much since the traffic is small, a couple of thousand visitors per day from the world. 

To better trace the charges, I decided to spin up another VM around 10PM Sep 28 2018 to track how much it will charge daily with this minimum f1-micro (1 vCPU, 0.6 GB memory) VM.

I choosed Ubuntu 16.04 (Xenial Xerus) on f1-micro. License is free for this OS. The only service enabled on this f1-micro VM is Mysql used as backend of my blog. FrontEnd is another PHP/APACHE VM hosting in another GCP account.  I have hardened the firewall rules to allow only MySQL in from a specific ip.

F1-Micro

Based on the GCP Always Free Usage Limits, I should be able to have following services as free:

• 1 f1-micro VM instance per month (US regions, excluding Northern Virginia).
• 30 GB of Standard persistent disk storage per month.
• 5 GB of snapshot storage per month.
• 1 GB egress from North America to other destinations per month (excluding Australia and China).

1. First Two days 
Here is first 32 hours charges and checked on Sep 30 2018:

	SKU	Product		Usage	Cost before Credit	credit
	Network Inter Zone Egress	Compute Engine		2.51 gibibyte	$0.03	-$0.03
	Micro instance with burstable CPU running in Americas	Compute Engine		32 hour	$0.02	-$0.02
	Network Internet Egress from Americas to China	Compute Engine		0 gibibyte	$0.00	-$0.00

Basic there are two charges:

• Network InterZone Charges.
• Micro instance with burstable CPU running in Americas

 Google Cloud Platform network pricing page, ingress traffic is free, while egress traffic is charged based on the source and destination of such traffic. Also both Google and AWS charge $0.01 per GB for inter-zone networking. This cost will happen even two VMs are in the same zone. My Apache2/Php front end vm is in same zone as my Mysql back end vm , which is us-east1-b. I will need to double check this one after a couple of days. 

GCP warned me instance "mysql1" is overutilised and let me consider switching to the machine type: g1-small (1 vCPU, 1.7 GB memory).

Performance Warning

As to bustable CPU charges, I checked the monitoring logs, it happened at the beginning when I just created the vm and imported the data. Based on Google Compute Engine Pricing page,  "f1-micro instances get 0.2 of a vCPU and are allowed to burst up to a full vCPU for short periods. g1-small instances get 0.5 of a vCPU and are allowed to burst up to a full vCPU for short periods."

I am guessing anytime if CPU is exceeding 20% usage, this charge kicks in. Here are two diagrams for first 32 hours and first 58 hours.

 

I got another $0.26 charges for last 26 hours because of burstable cpu usage.

2. Oct 1 CPU Usage and Cost

There is no CPU burstable cost for Oct 1. I checked CPU, and there is only one spike which is about 25%. 

3. Oct 1-2 CPU Usage and Cost

Product	Usage	Cost
Network Inter Zone Egress	6.47 gibibyte	$0.08
Network Internet Egress from Americas to China	0 gibibyte	$0.00

4. Oct 1-3 Cost and CPU Usage

SKU	Product	Usage	Cost before credit
Network Inter Zone Egress	Compute Engine	9.39 gibibyte	$0.12
Network Internet Egress from Americas to China	Compute Engine	0 gibibyte	$0.00

5. Oct 1-4 Cost and CPU Usage

SKU	Product	Usage	Cost before credit
Network Inter Zone Egress	Compute Engine	11.22 gibibyte	$0.15
Network Internet Egress from Americas to China	Compute Engine	0 gibibyte	$0.00

6. Oct 1-9 Cost and CPU Usage

SKU	Product	Usage	Cost before credit	Last 7 Days
Network Inter Zone Egress	Compute Engine	16.45 gibibyte	$0.21
Network Internet Egress from Americas to China	Compute Engine	5.15 gibibyte	$0.00

7. Oct 1-16 Cost

SKU	Product	Usage	Cost before credit	Last 7 Days
Network Inter Zone Egress	Compute Engine	18.27 gibibyte	$0.24
Storage PD Capacity	Compute Engine	0 gibibyte	$0.15

E2-Micro

Please check https://cloud.google.com/free/docs/gcp-free-tier#free-tier-usage-limits for more details for free tier:

If you found there is a small charge for disk, here is the trick part:

You will need to chose standard persistent disk rather than Balanced persistent disk. 

References:

• Google Cloud Platform免費套餐下暗藏的收費陷阱
• HOWTO: Set maximum CPU consumption in percentage by any process
• 2 Ways to Limit CPU Usage of a Process in Linux