Cloud computing: Myths and realities(2)

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By Tomi Davies

Claim 5: The Cloud Will Always Save Money on IT

Cost reduction is a primary business motivator for adopting cloud computing, but quantifying cost saving in building a business case is not always easy.

While quantifying cost savings is relatively easy for SaaS but becomes increasingly more difficult when it comes to PaaS and IaaS.

PaaS and Iaas often have factors that are difficult to measure, such as application modification time, running pilots, and the cost of training a staff in cloud computing skills, amongst many others.

The cloud offers financial savings in more than one way, however. The most obvious is the potential to reduce IT spending on existing requirements.

Another is how it allows a business to be more agile and increases revenue by providing low-cost, low-risk self-provisioning IT. This allows organisations to explore new opportunities that may have previously presented too high an investment risk/reward ratio.

In summary, when it comes to saving money on IT, small- and medium-size organisations can generally benefit from leveraging cloud computing. Larger organisations may not benefit financially from cloud computing due to the economies of scale that they can apply to on-premises IT provisioning. However, other advantages such as on-demand provisioning and reduced administration cloud computing may prove beneficial to the business and offset the cost differences.

Claim 6: Cloud Computing Resolves Performance Problems

Elasticity and a seemingly infinite amount of compute and storage capacity are often touted as major benefits of the cloud, but while these are clearly significant benefits, they are not measures of application performance. Poor performance issues are often caused by infrastructure capacity problems rather than poor application implementation. If an application running on a server becomes overloaded and all users are affected, then the users suffer poor response times, plus the application has a performance problem.

Cloud computing can certainly provide solutions to infrastructure capacity problems due to its elastic scalability, but performance will often vary. PaaS delivery models such as Google App Engine and Microsoft Azure provide satisfactory performance. The Google App Engine for example will provide an application with all the compute and storage capacity required, but it will not be high performance. Only IaaS can provide high performance, and even this isn’t always a sure bet.

There are a number of reasons why this is so. Cloud providers may oversell their capacity, causing performance problems that are totally out of the hands of the cloud user. In addition, virtualisation software runs on a multitenant architecture, and what other tenants are undertaking on that infrastructure plays a significant part in performance at any particular moment in time. So while the cloud provides the ability to improve performance problems through increased capacity, only satisfactory or acceptable performance, rather than high performance, should be expected.

Claim 7: All Software Should Be Moved to the Cloud

The attractive benefits of the cloud may encourage organisations to try to move all computing to the cloud. For some organisations, reducing the on-premises IT to an absolute minimum is appropriate. For others, internal IT departments with software development teams are essential as the bespoke software they develop enables the organisation to gain competitive advantage.

In considering what software is suitable for cloud delivery, key features such as self-provisioning, off-the-shelf, pay-per-use, elastically scalable, and access anywhere are all attractive and can help build a business case for cloud adoption. However, arguments against moving to the cloud include custom-built, on-premises software that is accessed only on the premises with little or no variation in load or demand.

Claim 8: It Is Easy to Switch Cloud Computing Vendors

As there are currently no standards in the cloud, moving from one provider to another is not a seamless process so in selecting providers, a number of key questions need to be asked.

For SaaS

How can I retrieve my data from the cloud, and what format will it be in?

Do other cloud providers support this data format?

Do any other providers provide equivalent applications?

For PaaS

Do other vendors support the platform?

Is the application tied to my current vendor’s platform?

How much work is required to rework my application to make it compatible with another vendor’s platform?

PaaS is the tightest coupling of vendors’ products, making it the most difficult to switch vendors. For example, an application using Microsoft’s Azure is tied to Azure. Similarly, an application developed for Force.com will only run on the Force.com platform. Some PaaS offerings provide looser couplings, such as Google App engine, but some modification to code is still required to move to another provider

For IaaS

Can another vendor easily recreate my infrastructure?

•    Does my application use vendor-specific infrastructure features?

•    How much work is required to rework my application to make it compatible with another vendor’s infrastructure?

Switching IaaS vendors can usually be achieved with minimal disruption. For example, a Linux infrastructure on Amazon EC2 can easily be replicated on GoGrid’s cloud. Similarly, Microsoft Office Live can read SaaS data stored on Google Apps

Claim 9: Cloud Computing Is Not Secure

Security is without a doubt the most debated cloud computing topic, and it is not possible to say definitively that cloud computing is or is not secure. While cloud computing presents unique security threats, the majority of them are general application and infrastructure concerns, which have proven solutions.

The major cloud-related security threats are loss of governance and those that result from multiple tenancy of cloud resources. If these can be resolved on a case-by-case basis, the cloud offers a computing environment at least as safe as non-cloud computing systems. Therefore much depends on the type of service utilised, the service provider and the service user.

Here are some of the factors related to security that should be considered:

Loss of governance — Tenants may not have control over certain issues, yet would still be responsible for their outcomes.

Isolation failure — In a multitenant environment, isolating tenants from each other is the responsibility of the cloud provider.

Compliance risks — If a cloud customer has to meet regulatory or industry standards then the failure of the cloud provider to meet the standards compromises the cloud customer.

Management interface compromise — A third party may gain unauthorised access to applications.

Data protection — Where is your data stored and how is access to it controlled? What procedures are in place to ensure complete data deletion?

Malicious insiders — Ultimately, some users have to have access to your cloud account, and the trust they are afforded may be broken.

Claim 10: Cloud Computing is computing as a Utility

Especially in the west, cloud computing is often considered utility computing where only a credit card payment is required to sign up and start using the services. From there, it is a pay-as-you-go model, just like any of their utilities at home. While this analogy is somewhat true, it is not the whole story.

In the same western world when you consider the process of selecting an electricity provider for the home. Factors that customers consider are price, reputation of the vendor and contract length, among others. But whichever vendor is selected, electricity is delivered to the home and all appliances work with it. Selecting a cloud provider is not so straightforward.

The lack of standards and platforms means it is very difficult, if not impossible, to directly compare what two providers offer. In many cases alternatives may not be available due to such factors as the programming language an application is developed in, and making a selection often includes a relatively lengthy pilot process to test the vendor’s products.

Conclusion

Many people are still unclear about the advantages and disadvantages of cloud computing.  In addition, vendors often promote it as a panacea and absolute necessity for competitive advantage. This article has attempted to clear up some of the confusion surrounding cloud computing by examining the main benefits as well as considering potential drawbacks.

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