Published lesson · 30 minutes
Plan locations and resilience
Objective: Describe regions and availability zones, place a service near its users where practical, and explain how redundancy and recovery reduce—but cannot eliminate—outage risk.
Start with the user need
A cloud region is a geographic area containing cloud infrastructure; many providers divide regions into separate availability zones. A design can spread suitable components across failure domains to reduce the impact of a localized fault. Choose locations based on user distance, legal and organizational requirements, available services, recovery objectives and cost. A second location helps only when data and recovery procedures are prepared too. Learners plan a registration service used by people in several South African provinces, with occasional access from elsewhere.
Make the trade-offs clear
For a small learning exercise, keep names and records fictional. First state the user need, then select the simplest design that meets it. Compare the benefit with a limitation such as connectivity, service dependency, configuration effort or recurring cost.
- Latency is the time for a request and response; nearer infrastructure can help, but networks and service design also affect it.
- Availability zones are separated failure domains within a region; their exact design and guarantees depend on the provider.
- A recovery point objective describes how much recent data loss is tolerable; a recovery time objective describes the time to restore service.
A cloud design is a set of trade-offs rather than a promise. Record assumptions about expected users, sensitive information, connectivity and the people who will operate the service. Revisit those assumptions when the audience or risk changes.
Practice scenario: Learners plan a registration service used by people in several South African provinces, with occasional access from elsewhere. Draw a simple location plan for the fictional registration service. Mark its primary region, a recovery option, one reason for the choices, and one assumption that still needs confirmation.
Worked examples
Plan locations and resilience: a design walkthrough
Walk through a provider-neutral decision for Learners plan a registration service used by people in several South African provinces, with occasional access from elsewhere. Explain the trade-offs and checks without provisioning a real service.
Practice tasks
Compare two choices
Draw a simple location plan for the fictional registration service. Mark its primary region, a recovery option, one reason for the choices, and one assumption that still needs confirmation.
Make a reviewable plan
Prepare a short, fictional plan for Learners plan a registration service used by people in several South African provinces, with occasional access from elsewhere. Include the service or design choice, the user benefit, a responsibility or risk and one way to check the result.
Explain a trade-off
Review your plan locations and resilience plan from the viewpoint of a learner and a service operator. Name one strength, one uncertainty and a practical next check.
Design for specific failure scenarios and prove that the recovery steps can meet real needs.
Course overview