The Pythagorean Theorem of Operational Risk

#devops It’s a simple equation, but one that is easily overlooked.

Most folks recall, I’m sure, the Pythagorean Theorem. If you don’t, what’s really important about the theorem is that any side of a right triangle can be computed if you know the other sides by using the simple formula a2 + b2 = c2. The really important thing about the theorem is that it clearly illustrates the relationship between three different pieces of a single entity. The lengths of the legs and hypotenuse of a triangle are intimately related; variations in one impact the others.

Operational risk – security, availability, performance – are interrelated in very much the same way. Changes to one impact the others. They cannot be completely separated. Much in the same way unraveling a braided rope will impact its strength, so too does unraveling the relationship between the three components of operational risk impact its overall success.


It is true that the theorem is not an exact match, primarily because concepts like performance and security are not easily encapsulated as concrete numerical values even if we apply mathematical concepts like Gödel numbering to it. While certainly we could use traditional metrics for availability and even performance (in terms of success at meeting specified business SLAs), still it would be difficult to nail these down in a way that makes the math make sense.

But the underlying concept - that it is always true* that the sides of a right triangle are interrelated is equally applicable to operational risk.

Consider that changes in performance impact what is defined as “availability” to end-users. Unacceptably slow applications are often defined as “unavailable” because they render it nearly impossible for end-users to work productively. Conversely, availability issues can negatively impact performance as fewer resources attempt to serve the same or more users. Security, too, is connected to both concepts, though it is more directly an enabler (or disabler) of availability and performance than vice-versa. Security solutions are not known for improving performance, after all, and the number of attacks directly attempting to negate availability is a growing concern for security. So, too, is the impact of attacks relevant to performance, as increasingly application-layer attacks are able to slip by security solutions and directly consume resources on web/application servers, degrading performance and ultimately resulting in a loss of availability.

But that is not to say that performance and availability have no impact on security at all. In fact the claim could be easily made that performance has a huge impact on security, as end-users demand more of the former and that often results in less of the latter because of the nature of traditional security solutions impact on performance.

Thus we are able to come back to the theorem in which the three sides of the data center triangle known as operational risk are, in fact, intimately linked. Changes in one impact the other, often negatively, and all three must be balanced properly in a way that maximizes them all.


Devops plays (or could and definitely should play) a unique role in organizations transforming from their traditional, static architectures toward the agile, dynamic architectures necessary to successfully execute on cloud and virtualization strategies. The role of devops focuses on automation and integration of the various delivery concerns that support the availability, performance, and security of applications. While they may not be the ones that define and implement security policies, they are the ones that should be responsible for assuring they are deployed and applied to applications as they move into the production environment. Similarly, devops may not be directly responsible for defining availability and performance requirements, but they are the ones that must configure and implement the appropriate health monitoring and related policies to ensure that all systems involved have the data they need to make the decisions required to meet operational requirements. Devops should be responsible for provisioning the appropriate services related to performance, security, and availability based on their unique role in the emerging data center model.

Devops isn’t just scripts and automation; it’s a role requiring unique skillset spanning networking, development, application delivery, and infrastructure integration. Devops must balance availability, performance, and security concerns and understand how the three are interrelated and impact each other. The devops team should be the ones that recognize gaps or failures in policies and are able to point them out, quickly.

The interrelationship between all three components of operational risk puts devops front and center when it comes to maintaining application deployments. Treating security, performance, and availability as separate and isolated concerns leads to higher risks that one will negatively impact the other. Devops is the logical point at which these three concerns converge, much in the same way application delivery is the logical data center tier at which all three concerns converge from a services and implementation point of view. Devops, like application delivery, has the visibility and control necessary to ensure that the three sides of the operational risk triangle are balanced properly.


* In Euclidian geometry, at least. Yes, other systems exist in which this may not be true, but c’mon, we’re essentially applying Gödel numbers to very abstract metrics and assuming axioms that have never been defined let alone proven so I think we can just agree to accept that this is always true in this version of reality. 

Published Nov 23, 2011
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