How Intersight Workload Optimizer Works
To keep your infrastructure in the desired state, IWO performs application resource management. This is an ongoing process that solves the problem of ensuring application performance while simultaneously achieving the most efficient use of resources and respecting environment constraints to comply to business rules. This is not a simple problem to solve. Application resource management has to consider many different resources and how they are used in relation to each other, in addition to numerous control points for each resource. As you grow your infrastructure, the factors for each decision increase exponentially. On top of that, the environment is constantly changing—to stay in the desired state, you are constantly trying to hit a moving target. To perform application resource management, IWO models the environment as a market made up of buyers and sellers. These buyers and sellers make up a supply chain that represents tiers of entities in your inventory. This supply chain represents the flow of resources from the data center, through the physical tiers of your environment, into the virtual tier and out to the cloud. By managing relationships between these buyers and sellers, IWO provides closed-loop management of resources, from the data center through to the application.
IWO uses virtual currency to give a budget to buyers and assign cost to resources. This virtual currency assigns value across all tiers of your environment, making it possible to compare the cost of application transactions with the cost of space on a disk or physical space in a data center. The price that a seller charges for a resource changes according to the seller’s supply. As demand increases, prices increase. As prices change, buyers and sellers react. Buyers are free to look for other sellers that offer a better price, and sellers can duplicate themselves (open new storefronts) to meet increasing demand. IWO uses its Economic Scheduling Engine to analyze the market and make these decisions. The effect is an invisible hand that dynamically guides your IT infrastructure to the optimal use of resources. To get the most out of IWO, you should understand how it models your environment, the kind of analysis it performs, and the desired state it works to achieve. Figure 5-5 illustrates the desired state graph for Infrastructure management.
Figure 5-5 Desired state graph for Infrastructure management
The goal of application resource management is to ensure performance while maintaining efficient use of resources. When performance and efficiency are both maintained, the environment is in the desired state. You can measure performance as a function of delay, where zero delay gives the ideal quality of service (QoS) for a given service. Efficient use of resources is a function of utilization, where 100% utilization of a resource is the ideal for the most efficient utilization.
If you plot delay and utilization, the result is a curve that shows a correlation between utilization and delay. Up to a point, as you increase utilization, the increase in delay is slight. There comes a point on the curve where a slight increase in utilization results in an unacceptable increase in delay. On the other hand, there is a point in the curve where a reduction in utilization doesn’t yield a meaningful increase in QoS. The desired state lies within these points on the curve.
You could set a threshold to post an alert whenever the upper limit is crossed. In that case, you would never react to a problem until delay has already become unacceptable. To avoid that late reaction, you could set the threshold to post an alert before the upper limit is crossed. In that case, you guarantee QoS at the cost of over-provisioning—you increase operating costs and never achieve efficient utilization.
Instead of responding after a threshold is crossed, IWO analyzes the operating conditions and constantly recommends actions to keep the entire environment within the desired state. If you execute these actions (or let IWO execute them for you), the environment will maintain operating conditions that ensure performance for your customers, while ensuring the lowest possible cost thanks to efficient utilization of your resources.