Replication & Failover Architecture
Cross-region active replication with automated failover triggers and sub-15-minute RTO.
Replication Models
Not all replication is equal. The right model depends on your RPO requirements, data consistency needs, and budget. CloudPresto designs replication architectures matched to workload criticality.
Synchronous Replication
Zero data loss (RPO = 0). Every write is confirmed by both primary and secondary before acknowledging to the application. Higher latency, but guaranteed consistency. Best for financial transactions and compliance-critical data.
Asynchronous Replication
Near-zero data loss (RPO = seconds to minutes). Writes are acknowledged by the primary immediately, then replicated in the background. Lower latency, but a small window of potential data loss during failover.
Semi-Synchronous
Hybrid model. At least one replica confirms the write before acknowledgement. Balances consistency and performance, suitable for most production workloads.
Logical Replication
Application-level replication for heterogeneous environments. Supports cross-platform, cross-version, and cross-region replication. More flexible but requires more careful monitoring.
Automated Failover
Manual failover is too slow. When a region goes down at 3 AM, you need automated detection and response, not a runbook someone has to read and execute under pressure.
Health Check Failure Detected
Multi-signal health monitoring detects the primary is unavailable. Not a single ping. Correlated checks across multiple endpoints and metrics to avoid false positives.
Quorum Confirmation
Multiple monitoring nodes confirm the failure. This prevents split-brain scenarios where network partitions trigger unnecessary failovers.
Failover Execution
Secondary promoted to primary. DNS updated, connections rerouted, application health verified. The entire process is automated with human notification, not human execution.
Post-Failover Validation
Automated checks confirm the new primary is serving correctly. Data integrity verified. Stakeholders notified with incident timeline and next steps.
Cross-Region Failover
For environments that require maximum resilience, we design failover architectures that span our own infrastructure across multiple continents: US, EU, and Asia.