func (u *Updater) worker(ctx context.Context, queue <-chan orchestrator.Slot) {
for slot := range queue {
// Do we have a task with the new spec in desired state = RUNNING?
// If so, all we have to do to complete the update is remove the
// other tasks. Or if we have a task with the new spec that has
// desired state < RUNNING, advance it to running and remove the
// other tasks.
var (
runningTask *api.Task
cleanTask *api.Task
)
for _, t := range slot {
if !u.isTaskDirty(t) {
if t.DesiredState == api.TaskStateRunning {
runningTask = t
break
}
if t.DesiredState < api.TaskStateRunning {
cleanTask = t
}
}
}
if runningTask != nil {
if err := u.useExistingTask(ctx, slot, runningTask); err != nil {
log.G(ctx).WithError(err).Error("update failed")
}
} else if cleanTask != nil {
if err := u.useExistingTask(ctx, slot, cleanTask); err != nil {
log.G(ctx).WithError(err).Error("update failed")
}
} else {
updated := orchestrator.NewTask(u.cluster, u.newService, slot[0].Slot, "")
if orchestrator.IsGlobalService(u.newService) {
updated = orchestrator.NewTask(u.cluster, u.newService, slot[0].Slot, slot[0].NodeID)
}
updated.DesiredState = api.TaskStateReady
if err := u.updateTask(ctx, slot, updated); err != nil {
log.G(ctx).WithError(err).WithField("task.id", updated.ID).Error("update failed")
}
}
if u.newService.Spec.Update != nil && (u.newService.Spec.Update.Delay.Seconds != 0 || u.newService.Spec.Update.Delay.Nanos != 0) {
delay, err := ptypes.Duration(&u.newService.Spec.Update.Delay)
if err != nil {
log.G(ctx).WithError(err).Error("invalid update delay")
continue
}
select {
case <-time.After(delay):
case <-u.stopChan:
return
}
}
}
}
func (r *Supervisor) shouldRestart(ctx context.Context, t *api.Task, service *api.Service) bool {
// TODO(aluzzardi): This function should not depend on `service`.
condition := orchestrator.RestartCondition(t)
if condition != api.RestartOnAny &&
(condition != api.RestartOnFailure || t.Status.State == api.TaskStateCompleted) {
return false
}
if t.Spec.Restart == nil || t.Spec.Restart.MaxAttempts == 0 {
return true
}
instanceTuple := instanceTuple{
instance: t.Slot,
serviceID: t.ServiceID,
}
// Instance is not meaningful for "global" tasks, so they need to be
// indexed by NodeID.
if orchestrator.IsGlobalService(service) {
instanceTuple.nodeID = t.NodeID
}
r.mu.Lock()
defer r.mu.Unlock()
restartInfo := r.history[instanceTuple]
if restartInfo == nil {
return true
}
if t.Spec.Restart.Window == nil || (t.Spec.Restart.Window.Seconds == 0 && t.Spec.Restart.Window.Nanos == 0) {
return restartInfo.totalRestarts < t.Spec.Restart.MaxAttempts
}
if restartInfo.restartedInstances == nil {
return true
}
window, err := ptypes.Duration(t.Spec.Restart.Window)
if err != nil {
log.G(ctx).WithError(err).Error("invalid restart lookback window")
return restartInfo.totalRestarts < t.Spec.Restart.MaxAttempts
}
lookback := time.Now().Add(-window)
var next *list.Element
for e := restartInfo.restartedInstances.Front(); e != nil; e = next {
next = e.Next()
if e.Value.(restartedInstance).timestamp.After(lookback) {
break
}
restartInfo.restartedInstances.Remove(e)
}
numRestarts := uint64(restartInfo.restartedInstances.Len())
if numRestarts == 0 {
restartInfo.restartedInstances = nil
}
return numRestarts < t.Spec.Restart.MaxAttempts
}
// Run contains the global orchestrator event loop
func (g *Orchestrator) Run(ctx context.Context) error {
defer close(g.doneChan)
// Watch changes to services and tasks
queue := g.store.WatchQueue()
watcher, cancel := queue.Watch()
defer cancel()
// lookup the cluster
var err error
g.store.View(func(readTx store.ReadTx) {
var clusters []*api.Cluster
clusters, err = store.FindClusters(readTx, store.ByName("default"))
if len(clusters) != 1 {
return // just pick up the cluster when it is created.
}
g.cluster = clusters[0]
})
if err != nil {
return err
}
// Get list of nodes
var nodes []*api.Node
g.store.View(func(readTx store.ReadTx) {
nodes, err = store.FindNodes(readTx, store.All)
})
if err != nil {
return err
}
for _, n := range nodes {
g.updateNode(n)
}
// Lookup global services
var existingServices []*api.Service
g.store.View(func(readTx store.ReadTx) {
existingServices, err = store.FindServices(readTx, store.All)
})
if err != nil {
return err
}
var reconcileServiceIDs []string
for _, s := range existingServices {
if orchestrator.IsGlobalService(s) {
g.updateService(s)
reconcileServiceIDs = append(reconcileServiceIDs, s.ID)
}
}
g.reconcileServices(ctx, reconcileServiceIDs)
for {
select {
case event := <-watcher:
// TODO(stevvooe): Use ctx to limit running time of operation.
switch v := event.(type) {
case state.EventUpdateCluster:
g.cluster = v.Cluster
case state.EventCreateService:
if !orchestrator.IsGlobalService(v.Service) {
continue
}
g.updateService(v.Service)
g.reconcileServices(ctx, []string{v.Service.ID})
case state.EventUpdateService:
if !orchestrator.IsGlobalService(v.Service) {
continue
}
g.updateService(v.Service)
g.reconcileServices(ctx, []string{v.Service.ID})
case state.EventDeleteService:
if !orchestrator.IsGlobalService(v.Service) {
continue
}
orchestrator.DeleteServiceTasks(ctx, g.store, v.Service)
// delete the service from service map
delete(g.globalServices, v.Service.ID)
g.restarts.ClearServiceHistory(v.Service.ID)
case state.EventCreateNode:
g.updateNode(v.Node)
g.reconcileOneNode(ctx, v.Node)
case state.EventUpdateNode:
g.updateNode(v.Node)
switch v.Node.Status.State {
// NodeStatus_DISCONNECTED is a transient state, no need to make any change
case api.NodeStatus_DOWN:
g.removeTasksFromNode(ctx, v.Node)
case api.NodeStatus_READY:
// node could come back to READY from DOWN or DISCONNECT
g.reconcileOneNode(ctx, v.Node)
}
case state.EventDeleteNode:
g.removeTasksFromNode(ctx, v.Node)
delete(g.nodes, v.Node.ID)
case state.EventUpdateTask:
if _, exists := g.globalServices[v.Task.ServiceID]; !exists {
continue
}
// global orchestrator needs to inspect when a task has terminated
// it should ignore tasks whose DesiredState is past running, which
// means the task has been processed
if isTaskTerminated(v.Task) {
g.restartTask(ctx, v.Task.ID, v.Task.ServiceID)
}
case state.EventDeleteTask:
// CLI allows deleting task
if _, exists := g.globalServices[v.Task.ServiceID]; !exists {
continue
}
g.reconcileServicesOneNode(ctx, []string{v.Task.ServiceID}, v.Task.NodeID)
}
case <-g.stopChan:
return nil
}
}
}
// Restart initiates a new task to replace t if appropriate under the service's
// restart policy.
func (r *Supervisor) Restart(ctx context.Context, tx store.Tx, cluster *api.Cluster, service *api.Service, t api.Task) error {
// TODO(aluzzardi): This function should not depend on `service`.
// Is the old task still in the process of restarting? If so, wait for
// its restart delay to elapse, to avoid tight restart loops (for
// example, when the image doesn't exist).
r.mu.Lock()
oldDelay, ok := r.delays[t.ID]
if ok {
if !oldDelay.waiter {
oldDelay.waiter = true
go r.waitRestart(ctx, oldDelay, cluster, t.ID)
}
r.mu.Unlock()
return nil
}
r.mu.Unlock()
// Sanity check: was the task shut down already by a separate call to
// Restart? If so, we must avoid restarting it, because this will create
// an extra task. This should never happen unless there is a bug.
if t.DesiredState > api.TaskStateRunning {
return errors.New("Restart called on task that was already shut down")
}
t.DesiredState = api.TaskStateShutdown
err := store.UpdateTask(tx, &t)
if err != nil {
log.G(ctx).WithError(err).Errorf("failed to set task desired state to dead")
return err
}
if !r.shouldRestart(ctx, &t, service) {
return nil
}
var restartTask *api.Task
if orchestrator.IsReplicatedService(service) {
restartTask = orchestrator.NewTask(cluster, service, t.Slot, "")
} else if orchestrator.IsGlobalService(service) {
restartTask = orchestrator.NewTask(cluster, service, 0, t.NodeID)
} else {
log.G(ctx).Error("service not supported by restart supervisor")
return nil
}
n := store.GetNode(tx, t.NodeID)
restartTask.DesiredState = api.TaskStateReady
var restartDelay time.Duration
// Restart delay is not applied to drained nodes
if n == nil || n.Spec.Availability != api.NodeAvailabilityDrain {
if t.Spec.Restart != nil && t.Spec.Restart.Delay != nil {
var err error
restartDelay, err = ptypes.Duration(t.Spec.Restart.Delay)
if err != nil {
log.G(ctx).WithError(err).Error("invalid restart delay; using default")
restartDelay = orchestrator.DefaultRestartDelay
}
} else {
restartDelay = orchestrator.DefaultRestartDelay
}
}
waitStop := true
// Normally we wait for the old task to stop running, but we skip this
// if the old task is already dead or the node it's assigned to is down.
if (n != nil && n.Status.State == api.NodeStatus_DOWN) || t.Status.State > api.TaskStateRunning {
waitStop = false
}
if err := store.CreateTask(tx, restartTask); err != nil {
log.G(ctx).WithError(err).WithField("task.id", restartTask.ID).Error("task create failed")
return err
}
r.recordRestartHistory(restartTask)
r.DelayStart(ctx, tx, &t, restartTask.ID, restartDelay, waitStop)
return nil
}