Consolidate the hardware. Plan the recovery.

The situation

Industrial control applications tend to accumulate on dedicated physical servers, each needing its own space, power, patching and eventual replacement. Consolidating them reduces hardware but concentrates risk: one host failure can affect many applications, so visibility and recovery have to improve at the same time.

What I look for

When control applications move onto shared, virtualized servers, I look at three things together: how much each application demands of the host, how its failure would be noticed, and how it would be recovered and verified. A consolidation is only as good as the recovery drill that proves it.

What it changes

Fewer physical servers to patch, power and eventually replace. In exchange, a single host failure now reaches many applications at once. Visibility into the shared platform, and a recovery that has actually been rehearsed, are what make that trade acceptable.

The engineering principle

Bringing applications onto shared infrastructure changes the consequences of a dependency failure. Resource demand, supportability, visibility and recovery need to be considered together.

INSIDE THE DECISION

What changes when applications share infrastructure?

The trade-off a consolidation decision has to resolve.

Questions for a design review

1. Understand application demand and support requirements.
2. Review shared dependencies and their consequences.
3. Define the evidence needed to recover and verify service.
4. Distinguish evaluation evidence from operational adoption.

An infrastructure decision should make the resulting support and recovery model easier to understand.