Add Spec.MindReadySeconds to allow setting a non-default value for Mi…

…nReadySeconds in StatefulSets. Set the default MinReadySeconds to 5 in StatefulSets to prevent sudden double restarts from statefulset controller.

CHANGELOG.md

@@ -15,6 +15,7 @@ Changelog for Cass Operator, new PRs should update the `main / unreleased` secti
 * [CHANGE] [#618](https://github.com/k8ssandra/cass-operator/issues/618) Update dependencies to support controller-runtime 0.17.2, modify required parts.
 * [ENHANCEMENT] [#628](https://github.com/k8ssandra/cass-operator/issues/628) Replace pod task can replace any node, including those that have crashed
 * [ENHANCEMENT] [#532](https://github.com/k8ssandra/cass-operator/issues/532) Instead of rejecting updates/creates with deprecated fields, return kubectl warnings.
+* [ENHANCEMENT] [#648](https://github.com/k8ssandra/cass-operator/issues/648) Add a default (5 seconds) MinReadySeconds to the StatefulSets and make that value configurable in the Spec
 
 ## v1.19.1
 

apis/cassandra/v1beta1/cassandradatacenter_types.go

@@ -258,6 +258,10 @@ type CassandraDatacenterSpec struct {
 	// Use cautiously.
 	// +optional
 	DatacenterName string `json:"datacenterName,omitempty"`
+
+	// MinReadySeconds sets the minimum number of seconds for which a newly created pod should be ready without any of its containers crashing, for it to be considered available. Defaults to 5 seconds and is set in the StatefulSet spec.
+	// Setting to 0 might cause multiple Cassandra pods to restart at the same time despite PodDisruptionBudget settings.
+	MinReadySeconds *int32 `json:"minReadySeconds,omitempty"`
 }
 
 type NetworkingConfig struct {

config/crd/bases/cassandra.datastax.com_cassandradatacenters.yaml

@@ -348,6 +348,12 @@ spec:
                     - serverSecretName
                     type: object
                 type: object
+              minReadySeconds:
+                description: |-
+                  MinReadySeconds sets the minimum number of seconds for which a newly created pod should be ready without any of its containers crashing, for it to be considered available. Defaults to 5 seconds and is set in the StatefulSet spec.
+                  Setting to 0 might cause multiple Cassandra pods to restart at the same time despite PodDisruptionBudget settings.
+                format: int32
+                type: integer
               networking:
                 properties:
                   hostNetwork:

pkg/reconciliation/construct_statefulset.go

@@ -145,13 +145,18 @@ func newStatefulSetForCassandraDatacenter(
 			PodManagementPolicy:  appsv1.ParallelPodManagement,
 			Template:             *template,
 			VolumeClaimTemplates: volumeClaimTemplates,
+			MinReadySeconds:      5,
 		},
 	}
 
 	if sts != nil && sts.Spec.ServiceName != "" && sts.Spec.ServiceName != result.Spec.ServiceName {
 		result.Spec.ServiceName = sts.Spec.ServiceName
 	}
 
+	if dc.Spec.MinReadySeconds != nil {
+		result.Spec.MinReadySeconds = *dc.Spec.MinReadySeconds
+	}
+
 	// add a hash here to facilitate checking if updates are needed
 	utils.AddHashAnnotation(result)