// evaluateNodePlan is used to evalute the plan for a single node,
// returning if the plan is valid or if an error is encountered
func evaluateNodePlan(snap *state.StateSnapshot, plan *structs.Plan, nodeID string) (bool, error) {
// If this is an evict-only plan, it always 'fits' since we are removing things.
if len(plan.NodeAllocation[nodeID]) == 0 {
return true, nil
}
// Get the node itself
node, err := snap.NodeByID(nodeID)
if err != nil {
return false, fmt.Errorf("failed to get node '%s': %v", nodeID, err)
}
// If the node does not exist or is not ready for schduling it is not fit
// XXX: There is a potential race between when we do this check and when
// the Raft commit happens.
if node == nil || node.Status != structs.NodeStatusReady || node.Drain {
return false, nil
}
// Get the existing allocations
existingAlloc, err := snap.AllocsByNode(nodeID)
if err != nil {
return false, fmt.Errorf("failed to get existing allocations for '%s': %v", nodeID, err)
}
// Filter on alloc state
existingAlloc = structs.FilterTerminalAllocs(existingAlloc)
// Determine the proposed allocation by first removing allocations
// that are planned evictions and adding the new allocations.
proposed := existingAlloc
var remove []*structs.Allocation
if update := plan.NodeUpdate[nodeID]; len(update) > 0 {
remove = append(remove, update...)
}
if updated := plan.NodeAllocation[nodeID]; len(updated) > 0 {
for _, alloc := range updated {
remove = append(remove, alloc)
}
}
proposed = structs.RemoveAllocs(existingAlloc, remove)
proposed = append(proposed, plan.NodeAllocation[nodeID]...)
// Check if these allocations fit
fit, _, _, err := structs.AllocsFit(node, proposed, nil)
return fit, err
}
func (iter *BinPackIterator) Next() *RankedNode {
OUTER:
for {
// Get the next potential option
option := iter.source.Next()
if option == nil {
return nil
}
// Get the proposed allocations
proposed, err := option.ProposedAllocs(iter.ctx)
if err != nil {
iter.ctx.Logger().Printf(
"[ERR] sched.binpack: failed to get proposed allocations: %v",
err)
continue
}
// Index the existing network usage
netIdx := structs.NewNetworkIndex()
netIdx.SetNode(option.Node)
netIdx.AddAllocs(proposed)
// Assign the resources for each task
total := new(structs.Resources)
for _, task := range iter.tasks {
taskResources := task.Resources.Copy()
// Check if we need a network resource
if len(taskResources.Networks) > 0 {
ask := taskResources.Networks[0]
offer, err := netIdx.AssignNetwork(ask)
if offer == nil {
iter.ctx.Metrics().ExhaustedNode(option.Node,
fmt.Sprintf("network: %s", err))
continue OUTER
}
// Reserve this to prevent another task from colliding
netIdx.AddReserved(offer)
// Update the network ask to the offer
taskResources.Networks = []*structs.NetworkResource{offer}
}
// Store the task resource
option.SetTaskResources(task, taskResources)
// Accumulate the total resource requirement
total.Add(taskResources)
}
// Add the resources we are trying to fit
proposed = append(proposed, &structs.Allocation{Resources: total})
// Check if these allocations fit, if they do not, simply skip this node
fit, dim, util, _ := structs.AllocsFit(option.Node, proposed, netIdx)
if !fit {
iter.ctx.Metrics().ExhaustedNode(option.Node, dim)
continue
}
// XXX: For now we completely ignore evictions. We should use that flag
// to determine if its possible to evict other lower priority allocations
// to make room. This explodes the search space, so it must be done
// carefully.
// Score the fit normally otherwise
fitness := structs.ScoreFit(option.Node, util)
option.Score += fitness
iter.ctx.Metrics().ScoreNode(option.Node, "binpack", fitness)
return option
}
}