First, thanks to those who wrote me, both online and offline, about my last post on the distribution of cluster node counts. As a follow-up, here’s a look at cluster asymmetry – that is, how often a cluster’s nodes are not identical. This is a non-academic question, since we’re in the process of adding new servers to SORT’s cluster. It’s been a few years since our last hardware refresh, so our server model is no longer available, plus all newer models come with more CPU and memory than our current boxes.
So, I looked at how often we see asymmetric clusters among configurations customers have uploaded to SORT:

As shown above, a third of the clusters showed any kind of asymmetry. Memory was the most common. A careful review of the graph shows ‘Any’ is less than the sum of the other categories. In...