415 lines
13 KiB
Go
415 lines
13 KiB
Go
package scheduler
|
|
|
|
import (
|
|
"fmt"
|
|
|
|
log "github.com/hashicorp/go-hclog"
|
|
"github.com/hashicorp/go-memdb"
|
|
"github.com/hashicorp/nomad/helper/uuid"
|
|
"github.com/hashicorp/nomad/nomad/structs"
|
|
)
|
|
|
|
const (
|
|
// maxSystemScheduleAttempts is used to limit the number of times
|
|
// we will attempt to schedule if we continue to hit conflicts for system
|
|
// jobs.
|
|
maxSystemScheduleAttempts = 5
|
|
)
|
|
|
|
// SystemScheduler is used for 'system' jobs. This scheduler is
|
|
// designed for services that should be run on every client.
|
|
// One for each job, containing an allocation for each node
|
|
type SystemScheduler struct {
|
|
logger log.Logger
|
|
state State
|
|
planner Planner
|
|
|
|
eval *structs.Evaluation
|
|
job *structs.Job
|
|
plan *structs.Plan
|
|
planResult *structs.PlanResult
|
|
ctx *EvalContext
|
|
stack *SystemStack
|
|
nodes []*structs.Node
|
|
nodesByDC map[string]int
|
|
|
|
limitReached bool
|
|
nextEval *structs.Evaluation
|
|
|
|
failedTGAllocs map[string]*structs.AllocMetric
|
|
queuedAllocs map[string]int
|
|
}
|
|
|
|
// NewSystemScheduler is a factory function to instantiate a new system
|
|
// scheduler.
|
|
func NewSystemScheduler(logger log.Logger, state State, planner Planner) Scheduler {
|
|
return &SystemScheduler{
|
|
logger: logger.Named("system_sched"),
|
|
state: state,
|
|
planner: planner,
|
|
}
|
|
}
|
|
|
|
// Process is used to handle a single evaluation.
|
|
func (s *SystemScheduler) Process(eval *structs.Evaluation) error {
|
|
// Store the evaluation
|
|
s.eval = eval
|
|
|
|
// Update our logger with the eval's information
|
|
s.logger = s.logger.With("eval_id", eval.ID, "job_id", eval.JobID, "namespace", eval.Namespace)
|
|
|
|
// Verify the evaluation trigger reason is understood
|
|
switch eval.TriggeredBy {
|
|
case structs.EvalTriggerJobRegister, structs.EvalTriggerNodeUpdate, structs.EvalTriggerFailedFollowUp,
|
|
structs.EvalTriggerJobDeregister, structs.EvalTriggerRollingUpdate, structs.EvalTriggerPreemption,
|
|
structs.EvalTriggerDeploymentWatcher, structs.EvalTriggerNodeDrain, structs.EvalTriggerAllocStop,
|
|
structs.EvalTriggerQueuedAllocs:
|
|
default:
|
|
desc := fmt.Sprintf("scheduler cannot handle '%s' evaluation reason",
|
|
eval.TriggeredBy)
|
|
return setStatus(s.logger, s.planner, s.eval, s.nextEval, nil, s.failedTGAllocs, structs.EvalStatusFailed, desc,
|
|
s.queuedAllocs, "")
|
|
}
|
|
|
|
// Retry up to the maxSystemScheduleAttempts and reset if progress is made.
|
|
progress := func() bool { return progressMade(s.planResult) }
|
|
if err := retryMax(maxSystemScheduleAttempts, s.process, progress); err != nil {
|
|
if statusErr, ok := err.(*SetStatusError); ok {
|
|
return setStatus(s.logger, s.planner, s.eval, s.nextEval, nil, s.failedTGAllocs, statusErr.EvalStatus, err.Error(),
|
|
s.queuedAllocs, "")
|
|
}
|
|
return err
|
|
}
|
|
|
|
// Update the status to complete
|
|
return setStatus(s.logger, s.planner, s.eval, s.nextEval, nil, s.failedTGAllocs, structs.EvalStatusComplete, "",
|
|
s.queuedAllocs, "")
|
|
}
|
|
|
|
// process is wrapped in retryMax to iteratively run the handler until we have no
|
|
// further work or we've made the maximum number of attempts.
|
|
func (s *SystemScheduler) process() (bool, error) {
|
|
// Lookup the Job by ID
|
|
var err error
|
|
ws := memdb.NewWatchSet()
|
|
s.job, err = s.state.JobByID(ws, s.eval.Namespace, s.eval.JobID)
|
|
if err != nil {
|
|
return false, fmt.Errorf("failed to get job '%s': %v",
|
|
s.eval.JobID, err)
|
|
}
|
|
numTaskGroups := 0
|
|
if !s.job.Stopped() {
|
|
numTaskGroups = len(s.job.TaskGroups)
|
|
}
|
|
s.queuedAllocs = make(map[string]int, numTaskGroups)
|
|
|
|
// Get the ready nodes in the required datacenters
|
|
if !s.job.Stopped() {
|
|
s.nodes, s.nodesByDC, err = readyNodesInDCs(s.state, s.job.Datacenters)
|
|
if err != nil {
|
|
return false, fmt.Errorf("failed to get ready nodes: %v", err)
|
|
}
|
|
}
|
|
|
|
// Create a plan
|
|
s.plan = s.eval.MakePlan(s.job)
|
|
|
|
// Reset the failed allocations
|
|
s.failedTGAllocs = nil
|
|
|
|
// Create an evaluation context
|
|
s.ctx = NewEvalContext(s.state, s.plan, s.logger)
|
|
|
|
// Construct the placement stack
|
|
s.stack = NewSystemStack(s.ctx)
|
|
if !s.job.Stopped() {
|
|
s.stack.SetJob(s.job)
|
|
}
|
|
|
|
// Compute the target job allocations
|
|
if err := s.computeJobAllocs(); err != nil {
|
|
s.logger.Error("failed to compute job allocations", "error", err)
|
|
return false, err
|
|
}
|
|
|
|
// If the plan is a no-op, we can bail. If AnnotatePlan is set submit the plan
|
|
// anyways to get the annotations.
|
|
if s.plan.IsNoOp() && !s.eval.AnnotatePlan {
|
|
return true, nil
|
|
}
|
|
|
|
// If the limit of placements was reached we need to create an evaluation
|
|
// to pickup from here after the stagger period.
|
|
if s.limitReached && s.nextEval == nil {
|
|
s.nextEval = s.eval.NextRollingEval(s.job.Update.Stagger)
|
|
if err := s.planner.CreateEval(s.nextEval); err != nil {
|
|
s.logger.Error("failed to make next eval for rolling update", "error", err)
|
|
return false, err
|
|
}
|
|
s.logger.Debug("rolling update limit reached, next eval created", "next_eval_id", s.nextEval.ID)
|
|
}
|
|
|
|
// Submit the plan
|
|
result, newState, err := s.planner.SubmitPlan(s.plan)
|
|
s.planResult = result
|
|
if err != nil {
|
|
return false, err
|
|
}
|
|
|
|
// Decrement the number of allocations pending per task group based on the
|
|
// number of allocations successfully placed
|
|
adjustQueuedAllocations(s.logger, result, s.queuedAllocs)
|
|
|
|
// If we got a state refresh, try again since we have stale data
|
|
if newState != nil {
|
|
s.logger.Debug("refresh forced")
|
|
s.state = newState
|
|
return false, nil
|
|
}
|
|
|
|
// Try again if the plan was not fully committed, potential conflict
|
|
fullCommit, expected, actual := result.FullCommit(s.plan)
|
|
if !fullCommit {
|
|
s.logger.Debug("plan didn't fully commit", "attempted", expected, "placed", actual)
|
|
return false, nil
|
|
}
|
|
|
|
// Success!
|
|
return true, nil
|
|
}
|
|
|
|
// computeJobAllocs is used to reconcile differences between the job,
|
|
// existing allocations and node status to update the allocations.
|
|
func (s *SystemScheduler) computeJobAllocs() error {
|
|
// Lookup the allocations by JobID
|
|
ws := memdb.NewWatchSet()
|
|
allocs, err := s.state.AllocsByJob(ws, s.eval.Namespace, s.eval.JobID, true)
|
|
if err != nil {
|
|
return fmt.Errorf("failed to get allocs for job '%s': %v",
|
|
s.eval.JobID, err)
|
|
}
|
|
|
|
// Determine the tainted nodes containing job allocs
|
|
tainted, err := taintedNodes(s.state, allocs)
|
|
if err != nil {
|
|
return fmt.Errorf("failed to get tainted nodes for job '%s': %v",
|
|
s.eval.JobID, err)
|
|
}
|
|
|
|
// Update the allocations which are in pending/running state on tainted
|
|
// nodes to lost
|
|
updateNonTerminalAllocsToLost(s.plan, tainted, allocs)
|
|
|
|
// Filter out the allocations in a terminal state
|
|
allocs, terminalAllocs := structs.FilterTerminalAllocs(allocs)
|
|
|
|
// Diff the required and existing allocations
|
|
diff := diffSystemAllocs(s.job, s.nodes, tainted, allocs, terminalAllocs)
|
|
s.logger.Debug("reconciled current state with desired state",
|
|
"place", len(diff.place), "update", len(diff.update),
|
|
"migrate", len(diff.migrate), "stop", len(diff.stop),
|
|
"ignore", len(diff.ignore), "lost", len(diff.lost))
|
|
|
|
// Add all the allocs to stop
|
|
for _, e := range diff.stop {
|
|
s.plan.AppendStoppedAlloc(e.Alloc, allocNotNeeded, "")
|
|
}
|
|
|
|
// Add all the allocs to migrate
|
|
for _, e := range diff.migrate {
|
|
s.plan.AppendStoppedAlloc(e.Alloc, allocNodeTainted, "")
|
|
}
|
|
|
|
// Lost allocations should be transitioned to desired status stop and client
|
|
// status lost.
|
|
for _, e := range diff.lost {
|
|
s.plan.AppendStoppedAlloc(e.Alloc, allocLost, structs.AllocClientStatusLost)
|
|
}
|
|
|
|
// Attempt to do the upgrades in place
|
|
destructiveUpdates, inplaceUpdates := inplaceUpdate(s.ctx, s.eval, s.job, s.stack, diff.update)
|
|
diff.update = destructiveUpdates
|
|
|
|
if s.eval.AnnotatePlan {
|
|
s.plan.Annotations = &structs.PlanAnnotations{
|
|
DesiredTGUpdates: desiredUpdates(diff, inplaceUpdates, destructiveUpdates),
|
|
}
|
|
}
|
|
|
|
// Check if a rolling upgrade strategy is being used
|
|
limit := len(diff.update)
|
|
if !s.job.Stopped() && s.job.Update.Rolling() {
|
|
limit = s.job.Update.MaxParallel
|
|
}
|
|
|
|
// Treat non in-place updates as an eviction and new placement.
|
|
s.limitReached = evictAndPlace(s.ctx, diff, diff.update, allocUpdating, &limit)
|
|
|
|
// Nothing remaining to do if placement is not required
|
|
if len(diff.place) == 0 {
|
|
if !s.job.Stopped() {
|
|
for _, tg := range s.job.TaskGroups {
|
|
s.queuedAllocs[tg.Name] = 0
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Record the number of allocations that needs to be placed per Task Group
|
|
for _, allocTuple := range diff.place {
|
|
s.queuedAllocs[allocTuple.TaskGroup.Name] += 1
|
|
}
|
|
|
|
// Compute the placements
|
|
return s.computePlacements(diff.place)
|
|
}
|
|
|
|
// computePlacements computes placements for allocations
|
|
func (s *SystemScheduler) computePlacements(place []allocTuple) error {
|
|
nodeByID := make(map[string]*structs.Node, len(s.nodes))
|
|
for _, node := range s.nodes {
|
|
nodeByID[node.ID] = node
|
|
}
|
|
|
|
nodes := make([]*structs.Node, 1)
|
|
for _, missing := range place {
|
|
node, ok := nodeByID[missing.Alloc.NodeID]
|
|
if !ok {
|
|
return fmt.Errorf("could not find node %q", missing.Alloc.NodeID)
|
|
}
|
|
|
|
// Update the set of placement nodes
|
|
nodes[0] = node
|
|
s.stack.SetNodes(nodes)
|
|
|
|
// Attempt to match the task group
|
|
option := s.stack.Select(missing.TaskGroup, nil)
|
|
|
|
if option == nil {
|
|
// If the task can't be placed on this node, update reporting data
|
|
// and continue to short circuit the loop
|
|
|
|
// If this node was filtered because of constraint mismatches and we
|
|
// couldn't create an allocation then decrementing queued for that
|
|
// task group
|
|
if s.ctx.metrics.NodesFiltered > 0 {
|
|
s.queuedAllocs[missing.TaskGroup.Name] -= 1
|
|
|
|
// If we are annotating the plan, then decrement the desired
|
|
// placements based on whether the node meets the constraints
|
|
if s.eval.AnnotatePlan && s.plan.Annotations != nil &&
|
|
s.plan.Annotations.DesiredTGUpdates != nil {
|
|
desired := s.plan.Annotations.DesiredTGUpdates[missing.TaskGroup.Name]
|
|
desired.Place -= 1
|
|
}
|
|
|
|
// Filtered nodes are not reported to users, just omitted from the job status
|
|
continue
|
|
}
|
|
|
|
// Check if this task group has already failed, reported to the user as a count
|
|
if metric, ok := s.failedTGAllocs[missing.TaskGroup.Name]; ok {
|
|
metric.CoalescedFailures += 1
|
|
continue
|
|
}
|
|
|
|
// Store the available nodes by datacenter
|
|
s.ctx.Metrics().NodesAvailable = s.nodesByDC
|
|
|
|
// Compute top K scoring node metadata
|
|
s.ctx.Metrics().PopulateScoreMetaData()
|
|
|
|
// Lazy initialize the failed map
|
|
if s.failedTGAllocs == nil {
|
|
s.failedTGAllocs = make(map[string]*structs.AllocMetric)
|
|
}
|
|
|
|
// Actual failure to start this task on this candidate node, report it individually
|
|
s.failedTGAllocs[missing.TaskGroup.Name] = s.ctx.Metrics()
|
|
s.addBlocked(node)
|
|
continue
|
|
}
|
|
|
|
// Store the available nodes by datacenter
|
|
s.ctx.Metrics().NodesAvailable = s.nodesByDC
|
|
|
|
// Compute top K scoring node metadata
|
|
s.ctx.Metrics().PopulateScoreMetaData()
|
|
|
|
// Set fields based on if we found an allocation option
|
|
resources := &structs.AllocatedResources{
|
|
Tasks: option.TaskResources,
|
|
Shared: structs.AllocatedSharedResources{
|
|
DiskMB: int64(missing.TaskGroup.EphemeralDisk.SizeMB),
|
|
},
|
|
}
|
|
|
|
// Create an allocation for this
|
|
alloc := &structs.Allocation{
|
|
ID: uuid.Generate(),
|
|
Namespace: s.job.Namespace,
|
|
EvalID: s.eval.ID,
|
|
Name: missing.Name,
|
|
JobID: s.job.ID,
|
|
TaskGroup: missing.TaskGroup.Name,
|
|
Metrics: s.ctx.Metrics(),
|
|
NodeID: option.Node.ID,
|
|
NodeName: option.Node.Name,
|
|
TaskResources: resources.OldTaskResources(),
|
|
AllocatedResources: resources,
|
|
DesiredStatus: structs.AllocDesiredStatusRun,
|
|
ClientStatus: structs.AllocClientStatusPending,
|
|
SharedResources: &structs.Resources{
|
|
DiskMB: missing.TaskGroup.EphemeralDisk.SizeMB,
|
|
},
|
|
}
|
|
|
|
// If the new allocation is replacing an older allocation then we record the
|
|
// older allocation id so that they are chained
|
|
if missing.Alloc != nil {
|
|
alloc.PreviousAllocation = missing.Alloc.ID
|
|
}
|
|
|
|
// If this placement involves preemption, set DesiredState to evict for those allocations
|
|
if option.PreemptedAllocs != nil {
|
|
var preemptedAllocIDs []string
|
|
for _, stop := range option.PreemptedAllocs {
|
|
s.plan.AppendPreemptedAlloc(stop, alloc.ID)
|
|
|
|
preemptedAllocIDs = append(preemptedAllocIDs, stop.ID)
|
|
if s.eval.AnnotatePlan && s.plan.Annotations != nil {
|
|
s.plan.Annotations.PreemptedAllocs = append(s.plan.Annotations.PreemptedAllocs, stop.Stub())
|
|
if s.plan.Annotations.DesiredTGUpdates != nil {
|
|
desired := s.plan.Annotations.DesiredTGUpdates[missing.TaskGroup.Name]
|
|
desired.Preemptions += 1
|
|
}
|
|
}
|
|
}
|
|
alloc.PreemptedAllocations = preemptedAllocIDs
|
|
}
|
|
|
|
s.plan.AppendAlloc(alloc)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// addBlocked creates a new blocked eval for this job on this node
|
|
// and submit to the planner (worker.go), which keeps the eval for execution later
|
|
func (s *SystemScheduler) addBlocked(node *structs.Node) error {
|
|
e := s.ctx.Eligibility()
|
|
escaped := e.HasEscaped()
|
|
|
|
// Only store the eligible classes if the eval hasn't escaped.
|
|
var classEligibility map[string]bool
|
|
if !escaped {
|
|
classEligibility = e.GetClasses()
|
|
}
|
|
|
|
blocked := s.eval.CreateBlockedEval(classEligibility, escaped, e.QuotaLimitReached())
|
|
blocked.StatusDescription = blockedEvalFailedPlacements
|
|
blocked.NodeID = node.ID
|
|
|
|
return s.planner.CreateEval(blocked)
|
|
}
|