Licence Metric Risk
The exposure created when a software licence is priced on a unit that cloud architecture changes unpredictably, such as cores, sockets or instances.
Enterprise licences are frequently priced per core, per socket, per named user or per instance — metrics designed for a world of fixed hardware. Cloud elasticity interacts with them badly, and the resulting bill is discovered at audit.
Concrete exposures: autoscaling multiplies per-instance licences; a larger instance family multiplies per-core licences even when total throughput is unchanged; containerisation can trigger licensing of every node the software might run on; and some vendors' terms count the entire cluster rather than the running workload.
The commercial mechanism that makes this serious is the audit clause: retrospective true-up at list price, without the discount a negotiated purchase would have carried.
Practices that contain it: read the metric definition before the architecture is chosen, since the licence can rule out a design; pin licensed workloads to dedicated hosts or node pools so the countable surface is bounded; track entitlement against actual deployment continuously rather than at audit; and model licence cost in migration business cases, where it is routinely omitted and frequently reverses the conclusion.
The strategic response, where the licence is a substantial share of TCO: treat migration to an open-source or consumption-priced alternative as a costed option rather than an ideological one — its value is largely the removal of this risk.