Intended Audience: Senior Technical Staff, Managers, CxOs
 What are hybrid clouds? Why do they exist?
Hybrid clouds are a set of technologies that is being widely adopted as a bridge between existing in-premise data centers and the fast growing public cloud ecosystem. Companies and large enterprises with massive investments in in-premise data centers are using hybrid cloud technologies to keep deriving value from their existing investments as well as benefit from the efficiencies that public clouds offer. It has also become clear that while public cloud adoption continues to increase rapidly, they cannot replace existing, proven in-house systems and processes entirely within a short period of time. In such an environment, hybrid clouds are providing a convenient mechanism for enterprises to try out the public clouds and adopt them in a phased manner if found fit for their application environments.
CTO and CIOs in large enterprises are continuously looking at ways to increase process efficiency, improve scalability of their applications and IT resources, and ways to reduce IT capital expenditure for short to mid-term requirements. They can see that public clouds vendors are fast building in all the technology and operational capabilities they need for such requirements. At the same time, they are also concerned about moving their entire application environment to a public cloud since it ‘seems’ to be outside their immediate areas of control and management. Some of them also believe that if there is a serious problem, they may not have the ability to resolve it since the infrastructure is now ‘outside’ their environment.
Since there is some element of truth to these concerns, hybrid clouds provide an excellent way to integrate the public cloud infrastructure into their existing environments so some of these concerns can be mitigated to a large extent. Hybrid Clouds are enabling the CxOs to retain control over their existing environments in a way they are familiar with and at the same time let them take advantage of the significant benefits that public cloud based infrastructure provides.
In a nutshell, instead of creating disconnected silos of computing infrastructure, the CxOs are using hybrid cloud bridges to seamlessly integrate their in-house data center with the public cloud infrastructure. Public cloud vendors are also providing excellent capabilities to enable such an integration. We will take a look at some of these capabilities in Part 2 of this article.
 A Few applications of Hybrid cloud technologies
For us to appreciate the applications and usefulness of hybrid cloud strategy, let us review a few known computing challenges and see how these challenges are being handled very well in a hybrid cloud environment.
A common pattern that is seen in many hybrid cloud applications is that first, the application workloads start with consuming in-house data center resources (typically compute); when the limits of computing resources is reached (virtual machines or jobs/requests in queue), on-demand instances in a pre-configured public cloud are created if there is a perceived loss of business. Perceived loss of business for an online e-commerce store could be losing its customer to its competitors and for a product company it would be like missing the deadline and thus ceding the market to competitors.
Once the on-demand resources have been created and setup in the cloud, it just looks like an extension of the existing in-premise resources and then computing jobs/requests can be sent there to be serviced. Let’s look at some real scenarios where hybrid clouds have proven their usefulness.
- Running long regression tests before code check-in
(Cloud Scenario: Test environment, Dev-ops)
In a typical development cycle of an enterprise class product, 80% of transactions come to land (on the code base) in last few weeks! All developers submit a long list of test cases to the test-farm (a cluster of powerful servers on which requested tests are scheduled to run) and wait for the test results hoping to see a “clean test run” so they can merge their changes into on the code base. In many instances, first run is never “clean”, requiring developers to fix the issue(s) and rerun all required test cases again. As a result we often see long queues to get the test run completed, which may potentially result in the developer missing the dreaded “code freeze” deadline!
A hybrid cloud based test environment is best suited to manage such peak demands that occur with regular frequency, but last for only a short period of time. If a hybrid environment has been pre-configured, tests can be scheduled on the new short-term instances created on-demand in a public cloud infrastructure — thus significantly reducing the waiting time for developers to complete their test cycles.
- Handling seasonal spikes on an e-commerce site
(Cloud Scenario: Retail application hosting, Online store)
Several e-commerce stores record almost 80% of their annual turnover around the holiday season or major festivals and sales. Again since the demand peaks occur frequently, but not continuously, hybrid clouds provide the best mechanism to handle them without investing heavily in infrastructure that lies unused during off-peak periods.With close monitoring of the demand in real-time, and the consequent increase in wait-time for the customers, the e-commerce store can decide to move a set of the items to be sold from the newly set-up on-demand instance on a public cloud, thereby distributing the load more efficiently and resulting in happier customers who can complete their purchases faster.
- Handling unprecedented load during flash sale of airline tickets
(Cloud Scenario: Online ticket booking)
To boost the top-line and to “acquire” new set of loyal customers, most budget airlines offer flash sales for a short period. Many times this kind of sale by one airline triggers announcements of sales by competitors — and in some instances, even the market leaders can not ignore the sale announced by a new entrant! Any airline that introduces such sales expects to see heavy customer load in a very short period of time and its vital for them to be ready to handle the sudden, short-term jump in potential customers.Such flash sales can result in unpredictable loads and no amount of planning may be enough to ensure enough compute and network resources when needed. Indeed, we have seen instance where flash sale sites become inaccessible to a large customer base, thereby defeating the very purpose of such a sale. In order to avoid potential loss of customers, goodwill and real business, travel companies can adopt a hybrid model where additional resources can be quickly setup to handle peak loads during flash sales and scaled down again when not needed. This would allow them to grow their business without incurring a huge cost on setting up compute infrastructure that gets used intermittently.
- Providing additional computing power to track a Tsunami
(Cloud Scenario: Virtual Data Center, Big Data & Analytics)
While the Met department of the government has got very powerful in-house servers, during Tsunamis, Cyclones, Hurricanes, etc. it requires additional computing power to run and re-run its weather modelling algorithms to determine the path of the impact – which can change many times in a few minutes – so affected people can be warned and evacuated. Also, after the impact, people across the world want to access the main site for information about the event, causing the main site to be almost non-responsive because of unpredictable load. Redistributing this load to a set of public cloud resources using hybrid technologies is a good way to manage modelling as well as user loads during major weather events.
In the next part of this article, we shall highlight some of the hybrid cloud solutions and technologies that are in common use and also review some of the pitfalls to avoid while setting up a hybrid cloud environment.