Reference Cluster module
cluster.availability
The cluster-wide availability requirement and the maximum level supported by the declared substrate.
cluster.availability contains the cluster default and the level its declared
capabilities can support.
| Field | Type | Default | Meaning |
|---|---|---|---|
default | none | pod | node | zone | substrate | Availability level passed to instances that do not override it. |
substrate | read-only level | derived | Highest level supported by cluster.capabilities. |
The levels form an ordered scale:
| Level | Workload must tolerate |
|---|---|
none | No failure guarantee. |
pod | One pod loss or a rolling update. |
node | One node loss. |
zone | One availability-zone loss. |
Substrate derivation
Section titled “Substrate derivation”| Capabilities | substrate |
|---|---|
multiNode = false | none |
more than one availabilityZones entry | zone |
| otherwise | node |
The result is certain only when the capabilities needed for that decision are
declared. Kix warns when a capability is unknown. It rejects a requested
default above a certain substrate.
cluster.capabilities.multiNode = true;cluster.capabilities.availabilityZones = [ "eu-west-1a" "eu-west-1b" ];cluster.availability.default = "zone";Packages receive the resolved level and map it onto replica counts, quorums, or HA features. Kix derives topology spread and PodDisruptionBudgets from the same level.