Quality of Service: Have Confidence in Your Cloud
April 16, 2012
Cloud computing is a term that has become part of our everyday conversations. More and more businesses want to be in the cloud and are taking steps to move to more virtual environments. According to the Open Data Center Alliance, more than 40 percent of its members expect to run more than 40 percent of internal IT systems in cloud environments within two years.
Recent discussions have also focused on the types of cloud services available. Whether businesses are using services such as Infrastructure as a Service (IaaS) or Software as a Service (SaaS), the end goal is the same: to reduce the costs of business operations. The challenge is to make sure businesses understand what each service offers and to determine which option makes the most sense for their specific cloud needs…
Defining cloud services
It is important to set a clear distinction between IaaS and SaaS. IaaS is a provisioning model used to support infrastructure operations, including storage, hardware, servers and networking components. The service provider owns the equipment and it typically requires a monthly fee. SaaS refers to the consumption of a software subscription model in which applications are hosted by a vendor or provider and is available over a network.
With IaaS, virtualization technology serves as the interface between the provider and the customer so that the customer has no control over the virtualization layer (hypervisor) or the underlying infrastructure (servers, networking and storage). But everything above that interface the customer has control of. This model adds flexibility and scalability, enabling customers to consume fractions of hardware to host their own application configurations.
In contrast, SaaS is run directly from a web browser without requiring any additional downloads or installations. In this model, hypervisors are rarely used, as the provider is offering a service that is scaled across hundreds or thousands of servers all sharing services, and abstraction and isolation are instituted at the customer or user level.
In either case, virtualization does not have to be a requirement. The technology can help to increase agility and reliability, as virtual machines can be moved, restarted or replicated as needed, but increasingly clouds are comprised of a mix of bare metal and virtual machines. Finally, virtualization does very little to ensure or improve the quality of service.
Considerations when moving to the cloud
Maximizing fewer but smarter resources is one of the many benefits of moving to a cloud infrastructure. The dynamic nature of cloud computing means that the physical infrastructure must be highly automated, reliable and elastic to deliver trusted, agile and cost effective computing services to successive layers of the cloud stack. To accomplish this goal, the physical infrastructure itself – the server hardware, virtual resources, the software payloads, the networks and the storage and communication I/O connections – must all be abstracted and defined in software.
Ultimately, the cloud allows for increased scalability via on-demand resources. Findings from the IBM Tech Trends Report found that 58 percent of respondents cited flexibility and scalability as the top drivers for implementing cloud computing. The cloud’s flexibility allows it to scale the IT infrastructure depending on the needs of the enterprise so that the time to start a business process is not contingent on IT infrastructure establishment time.
Although it clearly has many benefits, the challenge businesses face on a daily basis is making sure that their clouds can ensure reliable delivery and quality performance, especially with business-critical applications. For the cloud (SaaS or IaaS) to become the next enterprise computing platform, quality of service will be an area where providers need to show some real innovation.
What quality of service means
The ability to guarantee compute resources is critical as clouds constantly expand and contract to meet user demand, and because it ensures failures are automatically bypassed so end users are protected from interruptions. Quality of service means that businesses need to make sure that all applications have the capacity, availability and response time to meet service levels required by the business.
By having the compute capacity to take on a high demand or volume, applications are more accessible and available so that as big spikes happens, the system will automatically move applications to alternate physical and/or virtual servers. The system will move due to component failure or the need for more CPU and memory instead of forcing a frenzied reaction to an outage.
Goals for organizations moving to the cloud Ultimately, customers should focus on the level of service or performance the system is delivering from the perspective of the end user. Businesses need to make informed decisions regarding quality of service and how can they go about delivering it. These considerations include automating service level management, building for recovery, managing the virtual and physical together and enabling hardware heterogeneity.
Organizations should have three clear goals to ensure quality of service in the cloud:
- Make sure the service is available.
- Ensure that the capacity meets or exceeds the demand.
- Guarantee that user response time is acceptable.
Recent highly publicized outages should serve as wake-up calls for businesses and service providers to take a closer look at the infrastructure cloud providers are really offering. As more users move to the cloud, cloud outages have become more common, highlighting the need for security and quality of service. It is clear that organizations are starting to become more concerned with security and the recent outages have decreased their confidence in the cloud. It is now more important than ever to make sure that any cloud resources are deployed with quality of service in mind.
The cloud presents a great opportunity to be the next exciting, new platform of enterprise computing. Nevertheless, to live up to its full potential, businesses need to make sure the cloud is highly reliable, highly elastic and provides measurable services that respond quickly and smoothly to changing user demand. Regardless of the type of cloud environment, success depends on having the right technology foundation in place and on having the capability to ensure quality of service to the customer.