Blast radius
Before you apply a recommendation, see which connected resources it will impact and at what severity; on the architecture canvas.
Before you stop, delete, or modify a resource, the question that matters is “what else does this touch?” Blast Radius answers it visually: click a recommendation, and ZopNight highlights the connected resources the action would affect, classifies each by severity, and gives the whole change a risk score; all on the architecture canvas.
Blast Radius on the architecture canvas; the target resource, its connected resources coloured by impact, and a risk score with per-category breakdown.
How it works
Open blast radius
From a recommendation (or an autoscaler policy, or a schedule change), click View Blast Radius. The canvas overlay activates.
ZopNight builds the impact graph
A server-side adjacency graph, built from resource metadata (shared security groups, routing targets, attachments, triggers, parent links), identifies the resources one hop away from the target.
Read the canvas + side panel
The canvas colours the target blue, affected resources red, warnings amber, and safe resources green, dimming everything unrelated. The side panel lists the impact summary, per-resource detail, ownership (team / group / schedule), and the risk factors that drove the score.
Impact classification
Every connected resource is classified Affected, Warning, or Safe. The classification is resource-type-aware and operation-aware; the default for anything unmapped is Warning (Safe must be positively proven).
Modify operations
| Behaviour class | Example types | What happens to connections |
|---|---|---|
| Online modify | lambda, ebs, s3, ecs-service, K8s deployments, managed services | All connections safe: live update, no interruption |
| Restart modify | ec2, vm, rds, cloudsql, elasticache | Attached storage safe; load balancer warning (briefly offline); ASG warning (auto-replaces); DB safe; K8s pool parent affected (nodes recreated) |
| Pool modify | gke-nodepool, eks-nodegroup, aks-agentpool, asg, vmss, mig | Child nodes affected (recreated); cluster safe; storage warning (brief detach); services safe (endpoints auto-update) |
Delete / stop operations
Classified by the edge type between the target and its neighbour, and (for database edges) whether the neighbour is a database or a compute node:
- delete + parent link → affected (destroyed with parent)
- delete + attachment → warning (detached, data preserved)
- delete + trigger → affected (trigger breaks, invocations fail)
- delete + DB access → database neighbour affected (data lost); compute neighbour safe (DB is independent)
- stop + attachment → safe (storage preserved on all clouds)
- stop + DB access → database neighbour warning (connections terminated); compute neighbour safe
- cross-region + delete/stop → warning (replica promoted / serves stale data)
Risk score
Each analysis produces a risk score (0 = all safe, higher = riskier), combining impact severity (up to 60), environment (up to 15), and ownership spread (up to 20):
- Impact severity: affected counts full, warning counts half (up to 60 points)
- Environment: prod 15, staging 8, dev 3 (zeroed when nothing is impacted)
- Ownership spread: how many teams and schedules are touched (up to 20 points)
An all-safe blast radius scores 0.
How ZopNight detects the edges
| Edge | Detected from |
|---|---|
| DB access | AWS: shared security group · GCP: shared network · Azure: shared subnet |
| Routes to | Load balancer target metadata |
| Attached to | Volume/disk attachment metadata |
| Triggers | Lambda trigger UIDs, Cloud Run event sources |
| Member of | Resource parent link |
| Cross-region | Connection resources with a source and target resource |
Where you can launch it
| Entity | Behaviour |
|---|---|
| Resource | A single resource targeted by a recommendation |
| Autoscaler policy | The policy’s scaling target is the root; applying / removing / tuning shows the same connected set and risk score |
| Schedule | Update/delete pops a confirmation with View Blast Radius; shows attached resources and expandable groups with per-resource cost impact (monthly cost, current savings, after savings) |
Limits
Blast Radius is a decision aid, not a guarantee. Today it looks at one hop of neighbours, infers connectivity from resource metadata (not live VPC flow logs), and doesn’t reason about redundancy (it won’t tell you how many other healthy targets a load balancer still has). Treat it as “what could this touch,” then confirm with your own knowledge of the system.