The Cloud Integration Stack

#cloud Integrating environments occurs in layers …

We use the term “hybrid cloud” to indicate a joining together of two disparate environments. We often simplify the “cloud” to encompass public IaaS, PaaS, SaaS and private cloud. But even though the adoption of such hybrid architectures may be a foregone conclusion, the devil is, as they say, in the details and how that adoption will be executed is not so easily concluded.

At its core, cloud is about integrating infrastructure. We integrate infrastructure from the application and networking domains to enable elasticity and scalability. We integrate infrastructure from security and delivery realms to ensure a comprehensive, secure delivery chain that promises performance and reliability. We integrate infrastructure to manage these disparate worlds in a unified way, to reduce the burden on operations imposed by necessarily disconnected systems created by integrating environments.

How these integrations are realized can be broken down into a fairly simple stack comprised of the network, resources, elasticity, and control.

The NETWORK INTEGRATION LAYER

At the network layer, the goal is normalize connectivity and provide optimization of network traffic between two disconnected environments. This is generally applicable only to the integration of IaaS environments, where connectivity today is achieved primarily through the use of secured network tunnels. This enables secure communications over which data and applications may be transferred between environments (and why optimization for performance sake may be desired) and over which management can occur. The most basic of network integration enabling a hybrid cloud environment is often referred to as bridging, after the common networking term.

Bridging does not necessarily imply layer 3 normalization, however, and some sort of overlay networking technology will be required to achieve that normalization (and is often cited as a use of emerging technology like SDN).

Look for solutions in this layer to be included in cloud “bridges” or “bridging” offerings.

The RESOURCE INTEGRATION LAYER

At the resource layer, integration occurs at the virtualization layer. Resources such as compute and storage are integrated with data center residing systems in such a way as to be included in provisioning processes. This integration enables visibility into the health and performance of said resources, providing the means to collect actionable performance and status related metrics for everything from capacity planning to redistribution of clients to the provisioning of performance-related services such as acceleration and optimization.

This layer of integration is also heavily invested in the notion of maintaining operational consistency. One way this is achieved is by integrating remote resources into existing delivery network architectures that allow the enforcement of policy to ensure compliance with operational and business requirements.

Another means of achieving operational consistency through resource integration is to integrate remotely deployed infrastructure solutions providing application delivery services. Such resources can be integrated with data center deployed management systems in such a way as to enforce operational consistency through synchronization of policies across all managed environments, cloud or otherwise.

Look for solutions in this layer to be included in cloud “gateway” offerings.

The ELASTICITY INTEGRATION LAYER

Elasticity integration is closely related to resource integration but not wholly dependent upon it. Elasticity is the notion of expanding or contracting capacity of resources (whether storage, network, or compute) to meet demand. That elasticity requires visibility into demand (not as easy as it sounds, by the way) as well as integration with the broader systems that provision and de-provision resources.

Consider a hybrid cloud in which there is no network or resource integration, but rather systems are in place to aggregate demand metrics from both cloud and data center deployed applications. When some defined threshold is met, a trigger occurs that instructs the system to interact with the appropriate control-plane API to provision or de-provision resources. Elasticity requires not only the elasticity of compute capacity, but may also require network or storage capacity be adjusted as well. This is the primary reason why simple “launch a VM” or “stop a VM” responses to changes in demand are wholly inadequate to achieve true elasticity – such simple responses do not take into consideration the ecosystem that is cloud, regardless of its confines to a single public provider or its spread across multiple public/private locations.

True elasticity requires integration of the broader application delivery ecosystem to ensure consistent performance and security across all related applications.

Look for solutions in this layer to be included in cloud “gateway” offerings.

The CONTROL INTEGRATION LAYER

Finally, the control integration layer is particularly useful when attempting to integrate SaaS with private cloud or traditional data center models. This is primarily because integration at other layers is virtually non-existent (this is also true of PaaS environments, which are often highly self-contained and only truly enable integration and control over the application layer).

The control layer is focused on integrating processes, such as access and authentication, for purposes of maintaining control over security and delivery policies. This often involves some system under the organization’s control (i.e. in the data center) brokering specific functions as part of a larger process. Currently the most common control integration solution is the brokering of access to cloud hosted resources such as SaaS. The initial authentication and authorization steps of a broader log-in process occur in the data center, with the enterprise-controlled systems then providing assurance in the form of tokens or assertions (SAML, specifically crafted encrypted tokens, one time passwords, etc…) to the resource that the user is authorized to access the system.

Control integration layers are also used to manage disconnected instances of services across environments for purposes of operational consistency. This control enables the replication and synchronization of policies across environments to ensure security policy enforcement as well as consistent performance.

Look for solutions in this layer to be included in cloud “broker” offerings.

Eventually, the entire integration stack will be leveraged to manage hybrid clouds with confidence, eliminating many of the obstacles still cited by even excited prospective customers as reasons they are not fully invested in cloud computing .