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Test

A disaster recovery setup that has never been tested is an assumption. simplyblock DR rehearses a failover without touching production: it clones the replicated volumes on the target site, restores the application into renamed and isolated namespaces, validates that it comes up, reports the result, and tears everything down again. Production and replication stay unchanged, and the test proves this by comparing their state before and after.

Why Test

A test answers questions that configuration alone cannot:

  • Recoverability: Whether the replicated data and the captured Kubernetes objects are enough to start the application on the target site.
  • Boot order: Whether the tiers and readiness gates bring the application up in the right order.
  • Recovery point: How old the data on the target is at the time of the test (the achieved RPO).
  • Recovery time: How long the restore takes (the estimated RTO).

What a Test Proves and What It Never Exercises

A test failover exercises the restore of the application from the latest replicated consistency point and its startup on the target site. It never exercises the following, and every test report states so:

  • Promotion: The promotion of the replicated volumes on the target.
  • Fencing: The fencing of the source site.
  • External cutover: The preSource and postTargetReady external hooks, for example, DNS or load balancer changes.
  • Network identity: Routes, Ingresses, LoadBalancer addresses, and production network attachments.

A planned relocation (see Planned Failover) is the only way to exercise the complete move.

Readiness and Recent Tests

The readiness check test-recent runs on every DR path that declares the Test action. It warns, and the application's readiness on that path becomes Degraded, when no test along the path has passed, or when the last passed test is older than the path's test.recentWithin (default 720h, i.e., 30 days). A test of a recovery plan counts for each of its applications. On paths without Test, the check is not applicable.

Recurring tests with a test schedule keep this check green.

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