One major benefit of the IaaS model is the promise of elasticity to support unforeseen demand. This means that the Cloud vendor will provide the ability to quickly and easily scale the provided resources up or down, based on the actual usage requirements. This typically means that an organization can plan for the ″average″ case instead of the “worst case” of usage, simultaneously saving on costs and preventing outages.
Additionally, since the systems provided through cloud vendors are usually virtual machines running on the vendor’s underlying hardware, the process of adding new machines, increasing the disk space, or subscribing to new services is usually just a change through a web UI, instead of a complicated hardware or software acquisition process. This flexibility is an appealing factor because it significantly reduces the waiting time required to support a new capability.
However, this automation benefit is sometimes a hindrance to administrators and developers that need to access the low-level configuration settings of certain software. Additionally, since the services are being offered through a virtualized system, continuity in the underlying environment can’t be guaranteed. Some applications – for example, benchmarking tools – may not be suitable for that type of environment.
One appealing factor for the transition to the cloud is cost–but in certain situations, using the cloud may not actually be cheaper. Before making a decision, your organization should evaluate the following factors to make sure the transition will be beneficial.
One major benefit is the impact on your organization′s budget. If the costs are transitioned to the cloud, they will usually count as operational expenditures, as opposed to capital expenditures. In some situations, this might make a difference when trying to get the budget for the project approved.
Additionally, some savings may come in the form of reduced maintenance and licensing fees. These expenditures will be absorbed into the monthly cost, rather than being an upfront requirement.
When subscribing to the cloud, you can disable any unnecessary resources ondemand, reducing costs. In the same situation with real hardware, the servers would be required to remain on 24/7 in order to provide the same access benefits.
On the other hand, consider the size of the data. Vendors have costs associated with moving data into or out of the cloud, in addition to the charge for storage. In some cases, the data transfer time alone would prohibit the transition.
Also, the previously mentioned elasticity benefits that draw some people into the cloud–scaling up automatically to meet unexpected demand–can also have unexpected impact on the monthly bill. These costs are sometimes difficult to predict, and since the cloud computing pricing model is based on usage, it is important to weigh the possibility of an unanticipated hefty bill against an initial hardware investment.
Most cloud vendors typically guarantee service availability or access to customer support. This places that burden on the vendor, as opposed to being assumed by the project′s IT department.
Similarly, most cloud vendors provide backup and disaster recovery options either as add-ons or built-in to the main offering. This can be a benefit for smaller projects that have the requirement, but do not have the resources to support two full clusters internally.
However, even with these guarantees, vendors still need to perform routine maintenance on their hardware. Some server-side issues will result in virtual machines being disabled or relocated – usually communicated with some advanced notice. In certain cases this will cause interruptions and require manual interaction from the IT team.
All data and services that get transitioned into the cloud will be accessible from anywhere via the web–for better or worse. Using this system, the technique of isolating the hardware onto its own private network or behind a firewall is no longer possible. On the positive side, this means that everyone on the team will be able to work using any Internet-connected device. On the negative side, this means that every precaution needs to be taken so that the data stays safe from prying eyes.
For some organizations, the privacy concerns alone are enough to keep projects out of the cloud. Even assuming that the cloud can be made completely secure, stories in the news about data loss and password leakage will continue to project a negative perception of inherent danger. It is important to document all precautions being taken to protect the data and make sure that all affected parties in the organization are comfortable moving to the cloud.
The decision of whether or not to move into the cloud is an important one for any project or organization. The benefits of flexibility of hardware requirements, built–in support, and general automation must be weighed against the drawbacks of decreased control over the environment and privacy.
About the author
Kristen Hardwick has been gaining professional experience with software development in parallel computing environments in the private, public, and government sectors since 2007. She has interfaced with several different parallel paradigms, including Grid, Cluster, and Cloud. She started her software development career with Dynetics in Huntsville, AL, and then moved to Baltimore, MD, to work for Dynamics Research Corporation. She now works at Spry where her focus is on designing and developing big data analytics for the Hadoop ecosystem.