Cloud-Spanning

Cloud-spanning refers to applications that run across multiple cloud environments, which could be any combination of internal/private and external/public clouds.

Whereas cloud-bursting refers to the narrow case where applications expand into an external cloud in order to handle spikes in demand, cloud-spanning is a broader term that also encompasses scenarios in which an application’s components are more or less continuously distributed across multiple clouds. Hence cloud-spanning is an essential capability for taking advantage of the rapidly emerging hybrid cloud model.

By 2015 the majority of private cloud services will evolve to a hybrid mode.
Thomas Bittman, Gartner

Using a hybrid cloud model enables you to mix and match the resources between local infrastructure, which is typically a sunk cost but difficult to scale, with infrastructure that’s scalable and provisioned on demand. In many ways the hybrid cloud combines the best of both worlds – offering the security, data privacy, compliance, and control of the enterprise private cloud for sensitive workloads, as well as the greater elasticity of the public cloud to accommodate demand.

Working in a hybrid cloud requires at least two things:

  1. application services must be designed with the business logic separated from the details of their configuration and location
  2. applications must be capable of moving transparently between, and run unchanged, on multiple cloud infrastructures.

Monterey directly addresses both these requirements: Intelligent Application Mobility enables any part of the an application’s infrastructure to change in real-time while the application continues to run uninterrupted; and embedded into Monterey is the open-source jclouds cloud abstraction library that ensures Monterey-enabled applications can move freely between different cloud providers (subject to the user-defined policies being enforced by Monterey).

The benefits of cloud-spanning include:

  • Avoid Vendor Lock-in: As enterprises start connecting their internal clouds to public clouds, they need to ensure that they are not tied to a particular public cloud provider.
  • Create Best-of-Breed Ecosystems: external cloud providers will evolve in different directions to cater for specific requirements. For instance, some will specialize in IaaS or PaaS, others in particular industries, with others offering specific qualities of service such as SLA’s, increased security, higher performance etc. Cloud-spanning is essential for tapping into this potential.
  • Driving Efficiency across Locations: cloud-spanning enables processing to be ‘pushed’ to the provider and location where it makes the most sense from an efficiency and performance perspective.