Managed instance groups should span multiple zones
Managed Instance Groups (MIGs) should be configured for multi-zone deployments to ensure high availability and fault tolerance. A multi-zone MIG distributes instances across multiple zones within a region, protecting applications from zonal failures.
Running a MIG in a single zone creates a single point of failure. If that zone experiences an outage, all instances in the group become unavailable, resulting in application downtime during zonal failures, no automatic failover to healthy zones, and reduced resilience against infrastructure issues.
What this control checks
Managed Instance Groups span multiple zones for high availability
Audit evidence
Evidence that deployed resources meet this control: Prowler check compute_instance_group_multiple_zones (prowler gcp --checks compute_instance_group_multiple_zones).
Tool mappings
Use these identifiers to cross-reference this control across tools, reports, and evidence.
- Compliance.tf Control:
gcp_compute_instance_group_multiple_zones - Prowler Check:
compute_instance_group_multiple_zones
Last reviewed: 2026-10-09