Very shortly after cloud computing services were made available the need to integrate these cloud services with the existing on-premise systems was obvious. Whether we use the public internet or a dedicated line initially we did not have a term for this form of co-existence
Hybrid Cloud
Soon after the industry started to use the term Hybrid Cloud which has now become part of our vernacular. Initially I had an issue with this term as it encompassed integrating the public with any system that were hosted on premise, whether they were in a private cloud or a more traditional bare metal deployment. But this seems to have been rectified now.
Now I commonly see a Hybrid Cloud described as the strategy of utilizing and possibly the combination of cloud service both from a private cloud and from public cloud providers. The types of combinations possible between private and public cloud are varied, whether it involves environment propagation where businesses create parallel environments in which applications can move easily between private and public clouds, or functional distribution where parts of a system are deployed in the public cloud which interact with other parts of the same system which are deployed in the private cloud. The more ambitious use case is bursting where private cloud workloads may be replicated to the public cloud during times of peak demand.
Multi Cloud
The terms Multi Cloud and Hybrid Cloud are often used interchangeably. This has led to much confusion, while the two terms are related, they describe two distinct concepts.
Technical a multi cloud environment is when a business has 1 or more services from 2 or more cloud vendors. But if the business is not careful then this is just silos by another name. Therefore Multi Cloud must be seen as a strategy of utilizing and combining cloud services from multiple public cloud providers. Multi Cloud environments bring much flexibility and options but they also bring many challenges such as security, resource management, and cost management. These challenges will need to be addressed. I will cover some of these challenges in more detail in a future blog.
Multi Cloud doesn’t preclude a Hybrid Cloud strategy, but is complementary in nature to a Multi Cloud strategy. The two deployment models are not an either/or situation, but does require a holistic plan to make sure that their symbiotic relation is strategic in nature and not accidental. In future blogs I will cover some hybrid and multi cloud patterns to assist with this planning.
Hybrid IT
Not to leave the traditional data centers out of the mix we should consider how the more traditional data center deployments on bare metal or virtualized servers fit into this overall ecosystem. As I stated earlier the term Hybrid Cloud use to include or at least infer the interaction with traditional on-premise systems.
I like to use the term Hybrid IT to differentiate this scenario from Hybrid Clouds. Therefore Hybrid should be seen as a strategy of utilizing and combining on-premise resources with resources from private and/or public services.
Again this strategy does not preclude any Hybrid and Multi Cloud strategies as well.
Good Luck, Now Go Architect…
An Enterprise Architect's Musings 