Hybrid Cloud

In the recent Rightscale survey, 74% of the respondents mentioned that they have a multi-cloud strategy and 48% of the respondents are planning for hybrid clouds. The recent trend in Cloud computing after Public and Private cloud is Hybrid cloud. Hybrid cloud offers the best of Private and Public cloud in some scenarios and Enterprises seem to like that.

In this blog, I will cover the following:

  • What is Hybrid cloud and Multi-cloud?
  • Use cases for Hybrid cloud.
  • Components of Hybrid cloud and design considerations – Cloud management, Network connectivity, Application portability
  • Popular Hybrid cloud providers – Rightscale and AWS, Vmware VCHS, Cisco Intercloud, Rackspace hybrid cloud, Redhat open hybrid cloud

What is Hybrid cloud and Multi-cloud?

When an Enterprise’s cloud infrastructure is partly Private and partly Public, it is called as Hybrid cloud. Hybrid cloud can result in 2 ways. 1 way is an Enterprise with a private cloud needs an option to expand part of its offering into Public cloud and another way is an Enterprise with a public cloud wants to expand part of its offering into Private cloud. There could be different reasons for doing this and I will explain that in the Use cases below. There are some unique advantages of Private and Public cloud and the goal of Hybrid cloud would be to retain those advantages. In a Multi-cloud solution, an Enterprise will use multiple cloud providers for its different needs. This might be because an Enterprise does not want to be locked into a single provider or could be that a single cloud provider does not offer all features needed. Multi-cloud solution is a super-set of hybrid cloud.

Following picture shows a high level view of Hybrid cloud.


 Hybrid Cloud – Use cases

  •  Cloud bursting – Here, an Enterprise with Private cloud wants to move some portion of workload to public cloud when the demand is high like a seasonal variation.
  • Dev/Test Environment – Here, the development and testing tools are first tested in public cloud. Once the tools are proven, they are brought back into Private cloud for production environment.
  • Disaster recovery – Example of this scenario would be that the database from Private cloud is backed up in a public cloud and in case of any incident affecting the on-premise Private cloud, VMs are spawned in public cloud along with the backed up data.

Hybrid cloud – Components and Design considerations:

Network connectivity:

There is a need to have a fast, reliable and secure network between the different Clouds that we are planning to connect. Latency is an important consideration for some hybrid cloud applications. In Use cases like cloud bursting where the customer can run the web tier in 1 cloud and application and database tier in another cloud, latency becomes very important. In Use cases like disaster recovery, latency might not be an important consideration since only the data is backed up between the clouds. There are different kinds of Network connectivity options that I see. I have used AWS as reference, other cloud providers provide similar connectivity option with different naming convention.

  • Amazon Direct connect option – In this case, there is a need to have a dedicated link between the 2 clouds. This is possible only in scenarios where the private and public cloud are very close geographically. This option is more suitable for latency sensitive applications.
  • Amazon VPC – In this case, there is a VPN established between the customer enterprise to the public cloud. Also, the customer has more control over the finer networking details in the public cloud like subnets, private/public IP etc. There  is no latency guarantees with this option. Following picture shows how an example of private cloud connecting through VPN to Amazon AWS public cloud with VPC.


Cloud management:

Any Public or Private Cloud needs to have a Cloud orchestration software. Some of the popular cloud orchestration software are Openstack, Cloudstack, vCloud etc. In 1 of my previous blog, I have compared the different orchestration software. Cloud management layer sits on top of Cloud orchestration software layer and automates some of the common tasks which makes it easier to deploy and manage cloud applications. Cloud management software also allows to have a common single pane of glass access mechanism across different clouds. It is important to have some Cloud management software if we go with Hybrid cloud since the Cloud management software will take care of individual cloud orchestration software/provider specifics. There are many companies in this space like Rightscale, Enstratius, Scalr. Following picture from Rightscale shows where the Cloud management layer fits in and also describes some of the tasks that Rightscale’s cloud management solution does.


Application portability:

To migrate applications across Cloud providers, applications needs to be written the Cloud way. In 1 of my previous blog, I have covered the characteristics of a Cloud application.

Popular Hybrid cloud providers

This is not an extensive list below. I have added hybrid cloud providers that I am familar with. Also, my goal is to not compare providers but to provide some detail on each provider’s service.

Vmware Vcloud hybrid:

Vmware is targeting this solution towards Enterprise customers who are currently using ESX hypervisor and Vsphere kind of tools to migrate some of the workload towards Vmware provided public cloud. Looks like this solution is targeted as Vmware only solution. Also, this is Vmware’s initial entry as IaaS provider. Following picture from Vmware describes the block diagram of their solution.


Rackspace hybrid cloud:

Rackspace is a dominant private cloud player. They also have a hybrid solution called Rackconnect.



Rightscale is not a cloud provider, it is a cloud management company. Rightscale works closely with AWS and other cloud providers and facilitates Enterprises to have a multi-cloud solution. Following picture illustrates a hybrid cloud solution that Rightscale can provide.


Cisco Intercloud:

Cisco recently launched the Intercloud service where Enterprises can use this solution to have a multi-cloud or a hybrid cloud. The solution provided is hypervisor and cloud provider agnostic though intially the target will be a small set of hypervisor and cloud providers. Following picture illustrates components of Cisco Intercloud solution. The main components of the solution are Secure fabric that provides secure connectivity, Intercloud director that provides a single pane management of multiple clouds, Intercloud provider enablement platform that provides transformation agent across clouds.


Redhat open hybrid cloud:

Following picture from Redhat illustrates their hybrid solution.




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