scheduler: fixed a bug where the bandwidth of reserved cores were not taken into account

Author: mvegter

client/client.go

@@ -3335,8 +3335,7 @@ func (c *Client) setGaugeForDiskStats(hStats *hoststats.HostStats, baseLabels []
 func (c *Client) setGaugeForAllocationStats(baseLabels []metrics.Label) {
 	node := c.GetConfig().Node
 
-	available := node.NodeResources.Comparable()
-	available.Subtract(node.ReservedResources.Comparable())
+	available := node.Comparable()
 	allocated := c.getAllocatedResources(node)
 
 	// Emit allocated

nomad/structs/funcs.go

@@ -189,10 +189,8 @@ func AllocsFit(node *Node, allocs []*Allocation, netIdx *NetworkIndex, checkDevi
 		return false, "cores", used, nil
 	}
 
-	// Check that the node resources (after subtracting reserved) are a
-	// super set of those that are being allocated
-	available := node.NodeResources.Comparable()
-	available.Subtract(node.ReservedResources.Comparable())
+	// Check that the node resources are a super set of those that are being allocated
+	available := node.Comparable()
 	if superset, dimension := available.Superset(used); !superset {
 		return false, dimension, used, nil
 	}
@@ -232,11 +230,8 @@ func AllocsFit(node *Node, allocs []*Allocation, netIdx *NetworkIndex, checkDevi
 }
 
 func computeFreePercentage(node *Node, util *ComparableResources) (freePctCpu, freePctRam float64) {
-	// Determine the node availability
-	available := node.NodeResources.Comparable()
-	available.Subtract(node.ReservedResources.Comparable())
-
 	// Compute the free percentage
+	available := node.Comparable()
 	freePctCpu = 1 - (float64(util.Flattened.Cpu.CpuShares) / float64(available.Flattened.Cpu.CpuShares))
 	freePctRam = 1 - (float64(util.Flattened.Memory.MemoryMB) / float64(available.Flattened.Memory.MemoryMB))
 	return freePctCpu, freePctRam

nomad/structs/structs.go

@@ -2247,6 +2247,19 @@ func (n *Node) Canonicalize() {
 	}
 }
 
+// Comparable returns a comparable version of the node's resources available for scheduling.
+// This conversion can be lossy so care must be taken when using it.
+func (n *Node) Comparable() *ComparableResources {
+	if n == nil {
+		return nil
+	}
+
+	resources := n.NodeResources.Comparable()
+	resources.Subtract(n.ReservedResources.Comparable())
+
+	return resources
+}
+
 func (n *Node) Copy() *Node {
 	if n == nil {
 		return nil

scheduler/feasible/preemption.go

@@ -162,13 +162,7 @@ func (p *Preemptor) Copy() *Preemptor {
 
 // SetNode sets the node
 func (p *Preemptor) SetNode(node *structs.Node) {
-	nodeRemainingResources := node.NodeResources.Comparable()
-
-	// Subtract the reserved resources of the node
-	if c := node.ReservedResources.Comparable(); c != nil {
-		nodeRemainingResources.Subtract(c)
-	}
-	p.nodeRemainingResources = nodeRemainingResources
+	p.nodeRemainingResources = node.Comparable()
 }
 
 // SetCandidates initializes the candidate set from which preemptions are chosen