Cloud bursting — the dynamic deployment of applications that normally run on a private cloud to a public cloud — gives companies a new option for expanding their capacity to meet peak demands when the resources of their private clouds are not adequate. It’s an important technology because the use of private clouds is expected to increase in the 40 to 50 percent range over the next five years,1 and cloud bursting can make these private clouds much more cost efficient. The reason is simple. Instead of being built to support peak demands — which means supporting resources that will sit idle most of the time — private clouds can be built to run at high utilization rates because the peaks can be handled by a public cloud. A phrase sometimes used to describe this process from a business perspective is, “buy the base, rent the spike.”
Multiple Use Cases
A number of business situations can create spikes that impose an extra burden on a company’s private cloud. These include:
Seasonal variations. Many businesses experience seasonal variations in the number of transactions their data center must handle. Nearly all retailers experience a spike during the holiday season, and there are numerous other spikes for more vertically focused businesses such as ski and snowboarding equipment, back-to-school supplies , candy and flowers, health clubs and the travel industry.
Calendar-based spikes. Financial applications often create peaks related to heavy end-of-month, end-of-quarter and end-of-year activities.
Marketing activities. New product introductions, intensive ad campaigns or publicity in the media can lead to temporarily heavy website traffic. For some companies, high-profile TV ads are a regular event that can be guaranteed to create extra demand for IT resources.
Development projects. Software development teams often need to spin up a significant number of virtual machines for testing purposes, but these VMs are typically required only for a short period of time. Engineering activities in general can also create temporary demands.
Geographical issues. There are times when a data center in one location has a heavy load while another has extra capacity that can be used to ensure optimum application performance and response times that are within SLAs.
The Technical Issues
Cloud bursting enables companies to handle all of these use cases cost effectively. From a technical perspective, however, “renting the spike” requires careful planning to be successful.
To understand the issues and evaluate whether application-tier cloud bursting makes sense in any given situation, it’s worthwhile to take a step backward and look at what’s driving the popularity of private clouds in the first place.
Beyond general efficiency and improved hardware utilization, a number of important benefits are associated with building a private cloud. Cloud bursting technology can enhance these benefits, but to ensure success IT should bear in mind six technical issues.
Scalability. The pooled nature of resources in a private cloud allows applications to scale up and down in a matter of seconds depending on the resources they need at the moment. Cloud bursting dramatically extends this capability. The only concern is making sure that the public cloud vendor has committed resources adequate to the needs of application that will burst.
Performance. Assuming the private cloud is on-premise, transfer rates can be dramatically higher because data is moving over the company’s intranet, not the Internet. For the same reason, user access times are consistent and not subject to delays caused by variations in external traffic loads.
In a scenario where data must travel over the Internet, transfer rates may not be fast enough (or reliable enough) to ensure that cloud bursting is a viable option. Poor transfer rates mean user dissatisfaction at minimum and system crashes in the worst case. On the other hand, if the physical location of the public cloud provider is close enough, latency will not be an issue. In an ideal situation, the private cloud and public cloud are co-located.
Committed resources. Many IT managers prefer to have control over their physical resources because they want to know with certainty what resources are available and perhaps tune those resources for maximum performance with a particular application. In a private cloud, companies have that control. In addition, they aren’t dependent on the multi-tenant architecture of public clouds where they are compelled to share resources. Today, some public clouds address these concerns by offering dedicated server services. This option may be somewhat more expensive, but it is well worth the cost if dedicated resources are felt to be important.
Security/Regulatory Compliance. While concerns about the security of public clouds have diminished somewhat, security issues as they relate to regulatory compliance are still an important concern. Governmental agencies at the federal and state levels will hold enterprises accountable for the actions of their subcontractors when it comes to compliance.2 For this reason, companies that must comply with HIPAA, PCI or other such regulations should be sure their vendor is experienced and knowledgeable concerning best practices in this area.
Compatibility. Cloud bursting means operating an application in two different environments. In some cases, the application to be run in the public cloud when bursting may require some modifications to be compatible with this new environment.
Monitoring. While public clouds take care of all the infrastructure monitoring, customers still need to monitor their applications and will probably want to implement an integrating multi-cloud monitoring solution, many of which are available.
None of these issues present serious challenges. Any IT organization that is already operating a private cloud should be able to obtain the benefits of cloud bursting — particularly if the public cloud vendor offers strong customer support. Cloud bursting is an excellent approach to minimizing IT costs, and it also puts companies on the path to hybrid clouds, which many believe will become the norm in the near future.
1 Computerworld, July 17, 2014: http://www.computerworld.com/article/2490138/private-cloud/enterprises-increasingly-look-to-the-private-cloud.html
2 TechNet Magazine, May 2012, https://technet.microsoft.com/en-us/magazine/hh994647.aspx
Related Business Solution: Cloud Services