Simplify existing replica scheduling

Signed-off-by: Eric Weber <eric.weber@suse.com>
ejweber · Jul 28, 2023 · f48ec93 · f48ec93
1 parent 1d35e1d
commit f48ec93
Showing 1 changed file with 9 additions and 26 deletions.
diff --git a/scheduler/replica_scheduler.go b/scheduler/replica_scheduler.go
@@ -147,7 +147,7 @@ func (rcs *ReplicaScheduler) getDiskCandidates(nodeInfo map[string]*longhorn.Nod
 
 	nodeSoftAntiAffinity, err := rcs.ds.GetSettingAsBool(types.SettingNameReplicaSoftAntiAffinity)
 	if err != nil {
-		logrus.Errorf("error getting replica soft anti-affinity setting: %v", err)
+		logrus.Errorf("Error getting replica soft anti-affinity setting: %v", err)
 	}
 
 	if volume.Spec.ReplicaSoftAntiAffinity != longhorn.ReplicaSoftAntiAffinityDefault &&
@@ -213,8 +213,7 @@ func (rcs *ReplicaScheduler) getDiskCandidates(nodeInfo map[string]*longhorn.Nod
 	}
 
 	unusedNodes := map[string]*longhorn.Node{}
-	unusedNodesInNewZones := map[string]*longhorn.Node{}
-	nodesInUnusedZones := map[string]*longhorn.Node{}
+	unusedNodesInUnusedZones := map[string]*longhorn.Node{} // By definition, these nodes are also unused.
 	nodesWithEvictingReplicas := getNodesWithEvictingReplicas(replicas, nodeInfo)
 
 	for nodeName, node := range nodeInfo {
@@ -224,18 +223,18 @@ func (rcs *ReplicaScheduler) getDiskCandidates(nodeInfo map[string]*longhorn.Nod
 		}
 		if _, ok := usedNodes[nodeName]; !ok {
 			unusedNodes[nodeName] = node
-			if _, ok := usedZones[node.Status.Zone]; !ok {
-				unusedNodesInNewZones[nodeName] = node
-			}
 		}
 		if _, ok := usedZones[node.Status.Zone]; !ok {
-			nodesInUnusedZones[nodeName] = node
+			unusedNodesInUnusedZones[nodeName] = node
 		}
 	}
 
 	switch {
 	case !zoneSoftAntiAffinity && !nodeSoftAntiAffinity:
-		diskCandidates, errors := getDiskCandidatesFromNodes(unusedNodesInNewZones)
+		fallthrough
+	// Same as the above. If we cannot schedule two replicas in the same zone, we cannot schedule them on the same node.
+	case !zoneSoftAntiAffinity && nodeSoftAntiAffinity:
+		diskCandidates, errors := getDiskCandidatesFromNodes(unusedNodesInUnusedZones)
 		if len(diskCandidates) > 0 {
 			return diskCandidates, nil
 		}
@@ -246,7 +245,7 @@ func (rcs *ReplicaScheduler) getDiskCandidates(nodeInfo map[string]*longhorn.Nod
 		}
 		multiError.Append(errors)
 	case zoneSoftAntiAffinity && !nodeSoftAntiAffinity:
-		diskCandidates, errors := getDiskCandidatesFromNodes(unusedNodesInNewZones)
+		diskCandidates, errors := getDiskCandidatesFromNodes(unusedNodesInUnusedZones)
 		if len(diskCandidates) > 0 {
 			return diskCandidates, nil
 		}
@@ -261,24 +260,8 @@ func (rcs *ReplicaScheduler) getDiskCandidates(nodeInfo map[string]*longhorn.Nod
 			return diskCandidates, nil
 		}
 		multiError.Append(errors)
-	case !zoneSoftAntiAffinity && nodeSoftAntiAffinity:
-		diskCandidates, errors := getDiskCandidatesFromNodes(unusedNodesInNewZones)
-		if len(diskCandidates) > 0 {
-			return diskCandidates, nil
-		}
-		multiError.Append(errors)
-		diskCandidates, errors = getDiskCandidatesFromNodes(nodesInUnusedZones)
-		if len(diskCandidates) > 0 {
-			return diskCandidates, nil
-		}
-		multiError.Append(errors)
-		diskCandidates, errors = getDiskCandidatesFromNodes(nodesWithEvictingReplicas)
-		if len(diskCandidates) > 0 {
-			return diskCandidates, nil
-		}
-		multiError.Append(errors)
 	case zoneSoftAntiAffinity && nodeSoftAntiAffinity:
-		diskCandidates, errors := getDiskCandidatesFromNodes(unusedNodesInNewZones)
+		diskCandidates, errors := getDiskCandidatesFromNodes(unusedNodesInUnusedZones)
 		if len(diskCandidates) > 0 {
 			return diskCandidates, nil
 		}