According to a recent entry in IBM Cloudchat, the idea of a hybrid cloud is “poised to take flight” this year.  Last month we had the opportunity to join a Twitter discussion with IBM Distinguished Engineer and CTO Cloud Standards Christopher Ferris and IBM VP Scott Hebner, along with a number of other experts in the field of cloud computing to look at the potential for hybrid cloud systems.  Among other things, it seems that the hybrid approach may lend itself well to real-time cloud systems.

Definition
We started off by defining what “hybrid cloud” means.  Chris Ferris reminded us of the NIST definition: “in which two or more cloud types are discrete but networked together such that a burst of activity beyond the capabilities of one cloud is shifted for processing to another.”  In other words, a hybrid cloud is a linked combination of two or more types of cloud systems, such as public, private, or community.  Most of our discussion focused specifically on hybrids of public and private cloud systems.Participants were quick to expand on this basic definition.  There was some agreement that a hybrid cloud should provide “seamless integrated management and usage of different cloud services and in-house IT.”  This brings up two important ideas that may be implied but are not clearly spelled out in the NIST definition.  First is the necessity for a well-integrated way to coordinate between the two or more types of cloud in the hybrid.  Second, there is a practical need to consider effective coupling with in-house systems.  This is particularly true for many real-time systems.

Benefits and Risks
The benefits and risks of hybrid systems were summed up in this comment by Marcus Erber: The “benefit is to get the best of each world. Risk is the complexity of the environment.”  Some of the specific benefits mentioned by other participants included:

• Cloud bursting, which is the ability to handle sudden, heavy computing loads.
• Scaling resources, such as processing power or storage capacity, possibly in a more planned and controlled manner.
• Maintaining internal control & security on selected systems or data, which is often significant for industrial and mission-critical applications.
• Accessing public cloud resources from within your firewall, which is similar to the requirement for real-time cloud systems to reverse the client/server relationship.

One overall comment was that a hybrid cloud provides the benefits of scalability and lower costs associated with the public cloud, while allowing companies to keep mission critical applications managed in-house (in a private cloud).

The risks were felt to be similar to those of the public cloud in a general sense, with the added challenge of integration between the two systems.  Some of the specific risks and challenges highlighted were:

• Difficulty of achieving interoperability between cloud systems
• A need for maturity of cloud APIs
• Harder to achieve service levels specified in SLAs (Service Level Agreements)
• Matching SLAs between private and public cloud providers
• Avoiding vendor lock-in

As with other aspects of cloud computing, the general feeling among participants was that the benefits outweigh the potential risks, and the challenges can be met.  Even if we take in all the optimism with a grain of salt, there is some reason to expect to see a hybrid cloud in your future.

What would a hybrid cloud look like for a real-time system?  This is worth looking at in more detail, in our next blog.