Single vs Multi-Region
Driven by RTO, RPO and residency rather than by ambition.
3 to work through
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advanced
A collaborative product must decide between single-region, multi-region read replicas, and multi-region writable. What should decide it?
2 min answer -
advanced
A stakeholder asks for multi-region. What three questions do you ask before agreeing?
2 min answer -
advanced
A team must decide whether to run in one region or several. What evidence justifies multi-region, and what does it cost?
2 min answer
3 terms in this topic
Correlated Region Failure
The shared dependencies that make two regions fail together, which is why multiplying regions multiplies cost but adds far less availability than ind…
practiceRegion Selection Criteria
The factors determining where workloads run, in which data residency and latency usually dominate cost.
practiceRegion Strategy
How many regions, where, and in what topology — driven by residency, latency and availability requirements rather than by ambition.
Neighbouring topics
Architecture Decision-Making
General material on making and recording architectural decisions.
Architecture Decision Records
One decision, its context, alternatives and consequences, kept immutable.
Reversibility
One-way and two-way doors, and buying optionality deliberately.
Build vs Buy
Differentiation, five-year TCO, and the exit cost of each option.
Monolith vs Microservices
A team-topology decision far more often than a technology one.
SQL vs NoSQL
Decided by access patterns and query flexibility, not by data volume.
Sync vs Async
Whether the caller's outcome depends on the callee's response.
Strong vs Eventual Consistency
A per-operation decision, resolved by what a stale read would cost.
Managed vs Self-Managed
Trading control and unit cost against operational attention.
Serverless vs Containers
Spiky and event-driven versus sustained throughput.
Centralised vs Distributed
Shared platform leverage against team autonomy.
Performance vs Cost
Buying latency, and knowing what the last millisecond is worth.
Reliability vs Complexity
Mechanisms that add availability and add failure modes.
Security vs Usability
Varying control by the value of the action rather than uniformly.
Delivery vs Maintainability
Fast in the cheap places, careful in the expensive ones.
Deciding Under Uncertainty
Bounding the downside and buying information cheaply.
Trade-off Analysis Methods
ATAM, scenarios, and naming the points where qualities conflict.
Technology Selection
Evaluating options against drivers rather than against enthusiasm.
Decision Practice
Thresholds, review, supersession and keeping the log alive.