feat: refactor cmpd's role definition

apis/apps/v1/componentdefinition_types.go

@@ -415,11 +415,16 @@ type ComponentDefinitionSpec struct {
 	// +optional
 	Available *ComponentAvailable `json:"available,omitempty"`
 
+	// FIXME: there's a bug in CEL's cost estimation when chaining .filter() and .map().
+	// It was fixed in k8s 1.30, see: https://github.com/kubernetes/kubernetes/pull/123562.
+	// Maybe we can add this back later.
+	// TODO +kubebuilder:validation:XValidation:rule="self.filter(x, x.participatesInQuorum == true).map(x, x.updatePriority).min() > self.filter(x, x.participatesInQuorum == false).map(x, x.updatePriority).max()",message="Roles participate in quorum should have higher update priority than roles do not participate in quorum."
+
 	// Enumerate all possible roles assigned to each replica of the Component, influencing its behavior.
 	//
-	// A replica can have zero to multiple roles.
-	// KubeBlocks operator determines the roles of each replica by invoking the `lifecycleActions.roleProbe` method.
-	// This action returns a list of roles for each replica, and the returned roles must be predefined in the `roles` field.
+	// A replica can have zero or one role.
+	// KubeBlocks operator determines the role of each replica by invoking the `lifecycleActions.roleProbe` method.
+	// This action returns the role for each replica, and the returned role must be predefined here.
 	//
 	// The roles assigned to a replica can influence various aspects of the Component's behavior, such as:
 	//
@@ -430,6 +435,7 @@ type ComponentDefinitionSpec struct {
 	//
 	// This field is immutable.
 	//
+	// +kubebuilder:validation:MaxItems=128
 	// +optional
 	Roles []ReplicaRole `json:"roles,omitempty"`
 
@@ -1419,10 +1425,15 @@ type ComponentAvailableProbeAssertion struct {
 	Strict *bool `json:"strict,omitempty"`
 }
 
-// ReplicaRole represents a role that can be assumed by a component instance.
+// ReplicaRole represents a role that can be assigned to a component instance, defining its behavior and responsibilities.
 type ReplicaRole struct {
-	// Defines the role's identifier. It is used to set the "apps.kubeblocks.io/role" label value
-	// on the corresponding object.
+	// Name defines the role's unique identifier. This value is used to set the "apps.kubeblocks.io/role" label
+	// on the corresponding object to identify its role.
+	//
+	// For example, common role names include:
+	// - "leader": The primary/master instance that handles write operations
+	// - "follower": Secondary/replica instances that replicate data from the leader
+	// - "learner": Read-only instances that don't participate in elections
 	//
 	// This field is immutable once set.
 	//
@@ -1431,32 +1442,39 @@ type ReplicaRole struct {
 	// +kubebuilder:validation:Pattern=`^.*[^\s]+.*$`
 	Name string `json:"name"`
 
-	// Indicates whether a replica assigned this role is capable of providing services.
+	// UpdatePriority determines the order in which pods with different roles are updated.
+	// Pods are sorted by this priority (higher numbers = higher priority) and updated accordingly.
+	// Roles with the highest priority will be updated last.
+	// The default priority is 0.
 	//
-	// This field is immutable once set.
-	//
-	// +kubebuilder:default=false
-	// +optional
-	Serviceable bool `json:"serviceable,omitempty"`
-
-	// Determines if a replica in this role has the authority to perform write operations.
-	// A writable replica can modify data, handle update operations.
+	// For example:
+	// - Leader role may have priority 2 (updated last)
+	// - Follower role may have priority 1 (updated before leader)
+	// - Learner role may have priority 0 (updated first)
 	//
 	// This field is immutable once set.
 	//
-	// +kubebuilder:default=false
+	// +kubebuilder:default=0
 	// +optional
-	Writable bool `json:"writable,omitempty"`
+	UpdatePriority int `json:"updatePriority"`
 
-	// Specifies whether a replica with this role has voting rights.
-	// In distributed systems, this typically means the replica can participate in consensus decisions,
-	// configuration changes, or other processes that require a quorum.
+	// ParticipatesInQuorum indicates if pods with this role are counted when determining quorum.
+	// This affects update strategies that need to maintain quorum for availability. Roles participate
+	// in quorum should have higher update priority than roles do not participate in quorum.
+	// The default value is false.
+	//
+	// For example, in a 5-pod component where:
+	// - 2 learner pods (participatesInQuorum=false)
+	// - 2 follower pods (participatesInQuorum=true)
+	// - 1 leader pod (participatesInQuorum=true)
+	// The quorum size would be 3 (based on the 3 participating pods), allowing parallel updates
+	// of 2 learners and 1 follower while maintaining quorum.
 	//
 	// This field is immutable once set.
 	//
 	// +kubebuilder:default=false
 	// +optional
-	Votable bool `json:"votable,omitempty"`
+	ParticipatesInQuorum bool `json:"participatesInQuorum"`
 }
 
 // UpdateStrategy defines the update strategy for cluster components. This strategy determines how updates are applied

apis/workloads/v1/instanceset_types.go

@@ -291,11 +291,6 @@ type InstanceSetStatus struct {
 	// +optional
 	MembersStatus []MemberStatus `json:"membersStatus,omitempty"`
 
-	// Indicates whether it is required for the InstanceSet to have at least one primary instance ready.
-	//
-	// +optional
-	ReadyWithoutPrimary bool `json:"readyWithoutPrimary,omitempty"`
-
 	// currentRevisions, if not empty, indicates the old version of the InstanceSet used to generate the underlying workload.
 	// key is the pod name, value is the revision.
 	//
@@ -330,33 +325,9 @@ const (
 	PreferInPlacePodUpdatePolicyType PodUpdatePolicyType = "PreferInPlace"
 )
 
-type ReplicaRole struct {
-
-	// Defines the role name of the replica.
-	//
-	// +kubebuilder:validation:Required
-	// +kubebuilder:default=leader
-	Name string `json:"name"`
-
-	// Specifies the service capabilities of this member.
-	//
-	// +kubebuilder:validation:Required
-	// +kubebuilder:default=ReadWrite
-	// +kubebuilder:validation:Enum={None, Readonly, ReadWrite}
-	AccessMode AccessMode `json:"accessMode"`
-
-	// Indicates if this member has voting rights.
-	//
-	// +kubebuilder:default=true
-	// +optional
-	CanVote bool `json:"canVote"`
-
-	// Determines if this member is the leader.
-	//
-	// +kubebuilder:default=false
-	// +optional
-	IsLeader bool `json:"isLeader"`
-}
+// ReplicaRole represents a role that can be assigned to a component instance, defining its behavior and responsibilities.
+// +kubebuilder:object:generate=false
+type ReplicaRole = kbappsv1.ReplicaRole
 
 // AccessMode defines SVC access mode enums.
 // +enum
@@ -604,18 +575,5 @@ func (r *InstanceSet) IsInstanceSetReady() bool {
 		return true
 	}
 	membersStatus := r.Status.MembersStatus
-	if len(membersStatus) != int(*r.Spec.Replicas) {
-		return false
-	}
-	if r.Status.ReadyWithoutPrimary {
-		return true
-	}
-	hasLeader := false
-	for _, status := range membersStatus {
-		if status.ReplicaRole != nil && status.ReplicaRole.IsLeader {
-			hasLeader = true
-			break
-		}
-	}
-	return hasLeader
+	return len(membersStatus) == int(*r.Spec.Replicas)
 }

config/crd/bases/apps.kubeblocks.io_componentdefinitions.yaml

@@ -8427,9 +8427,9 @@ spec:
                   Enumerate all possible roles assigned to each replica of the Component, influencing its behavior.
 
 
-                  A replica can have zero to multiple roles.
-                  KubeBlocks operator determines the roles of each replica by invoking the `lifecycleActions.roleProbe` method.
-                  This action returns a list of roles for each replica, and the returned roles must be predefined in the `roles` field.
+                  A replica can have zero or one role.
+                  KubeBlocks operator determines the role of each replica by invoking the `lifecycleActions.roleProbe` method.
+                  This action returns the role for each replica, and the returned role must be predefined here.
 
 
                   The roles assigned to a replica can influence various aspects of the Component's behavior, such as:
@@ -8443,49 +8443,65 @@ spec:
 
                   This field is immutable.
                 items:
-                  description: ReplicaRole represents a role that can be assumed by
-                    a component instance.
+                  description: ReplicaRole represents a role that can be assigned
+                    to a component instance, defining its behavior and responsibilities.
                   properties:
                     name:
                       description: |-
-                        Defines the role's identifier. It is used to set the "apps.kubeblocks.io/role" label value
-                        on the corresponding object.
+                        Name defines the role's unique identifier. This value is used to set the "apps.kubeblocks.io/role" label
+                        on the corresponding object to identify its role.
+
+
+                        For example, common role names include:
+                        - "leader": The primary/master instance that handles write operations
+                        - "follower": Secondary/replica instances that replicate data from the leader
+                        - "learner": Read-only instances that don't participate in elections
 
 
                         This field is immutable once set.
                       maxLength: 32
                       pattern: ^.*[^\s]+.*$
                       type: string
-                    serviceable:
+                    participatesInQuorum:
                       default: false
                       description: |-
-                        Indicates whether a replica assigned this role is capable of providing services.
+                        ParticipatesInQuorum indicates if pods with this role are counted when determining quorum.
+                        This affects update strategies that need to maintain quorum for availability. Roles participate
+                        in quorum should have higher update priority than roles do not participate in quorum.
+                        The default value is false.
 
 
-                        This field is immutable once set.
-                      type: boolean
-                    votable:
-                      default: false
-                      description: |-
-                        Specifies whether a replica with this role has voting rights.
-                        In distributed systems, this typically means the replica can participate in consensus decisions,
-                        configuration changes, or other processes that require a quorum.
+                        For example, in a 5-pod component where:
+                        - 2 learner pods (participatesInQuorum=false)
+                        - 2 follower pods (participatesInQuorum=true)
+                        - 1 leader pod (participatesInQuorum=true)
+                        The quorum size would be 3 (based on the 3 participating pods), allowing parallel updates
+                        of 2 learners and 1 follower while maintaining quorum.
 
 
                         This field is immutable once set.
                       type: boolean
-                    writable:
-                      default: false
+                    updatePriority:
+                      default: 0
                       description: |-
-                        Determines if a replica in this role has the authority to perform write operations.
-                        A writable replica can modify data, handle update operations.
+                        UpdatePriority determines the order in which pods with different roles are updated.
+                        Pods are sorted by this priority (higher numbers = higher priority) and updated accordingly.
+                        Roles with the highest priority will be updated last.
+                        The default priority is 0.
+
+
+                        For example:
+                        - Leader role may have priority 2 (updated last)
+                        - Follower role may have priority 1 (updated before leader)
+                        - Learner role may have priority 0 (updated first)
 
 
                         This field is immutable once set.
-                      type: boolean
+                      type: integer
                   required:
                   - name
                   type: object
+                maxItems: 128
                 type: array
               runtime:
                 description: |-