The pros and cons of using a virtual private cloud

VPCs (virtual private clouds) were really a marketing response by public cloud providers that found themselves competing with private clouds, such as OpenStack, years ago. Some enterprises did not relish the idea of placing their data on a public cloud, sharing pooled resources with other companies—perhaps even their competition.

I was in so many of those meetings back then, hearing CIOs proclaim that their data would never exist outside of their firewall. When moving to cloud, it was going to be their cloud in their data center: a private cloud.

The trouble with private clouds is that they still have a subset of the same features and functions as the public cloud providers. Moreover, private clouds still require buying hardware and software, renting or buying data center space, as well as hiring humans to take care of it all. There was typically negative value to using private clouds and no real security benefits.

VPCs are defined a bit differently depending on which cloud provider or MSP (managed services provider) you select, but they have a few patterns in common:

• Your processing and data storage systems are not intermingled with other tenants. This is accomplished by using physical and virtual mechanisms managed by the cloud computing provider. 
• You’ll get a unique private IP subnet that you’ll leverage as if the hardware and software were down the hall.
• You’ll use secure virtual communications, such as a VLAN or VPN. In some cases these connections use the open Internet; in other cases they may have a dedicated circuit directly to the cloud provider.

The advantages of a VPC are that you’re able to functionally use your own private cloud using secure service and you’ll have access to all features and functions of the public cloud computing provider hosting your VPC. There are also some disadvantages to consider.

First is the cost. Of course, it depends on your public cloud provider or MSP, but in all cases a VPC costs more to operate than standard cloud hosting. In some instances it is more expensive than operating a private cloud on premises.

You need to consider ingress and egress costs of data moving in and out of the VPC, plus the cost of a private connection per hour. There are other extras that you can choose as well, and it won’t be long until the value of a VPC has gone into the red. 

Latency could be an issue for those that use VPCs over the open Internet using a private connection. Of course, this depends on where you are using the VPC in relation to the physical point of presence, how chatty the application is, and the type of VPN encryption.

If you gave me a choice of a private cloud or a VPC, I would likely pick the VPC for a standard deployment. It never made sense to me to build net-new physical hardware and software systems. Considering the lack of “table stakes features” that private clouds offer (and enterprises require), with a very few exceptions, private cloud is rarely an option.