@@ -128,7 +128,7 @@ github.com/containerd/ttrpc                         92c8520ef9f86600c650dd540266

 github.com/gogo/googleapis                          d31c731455cb061f42baff3bda55bad0118b126b # v1.2.0

 # cluster

-github.com/docker/swarmkit                          062b694b46c0744d601eebef79f3f7433d808a04 # bump_v19.03 branch

+github.com/docker/swarmkit                          0b8364e7d08aa0e972241eb59ae981a67a587a0e # bump_v19.03 branch

 github.com/gogo/protobuf                            ba06b47c162d49f2af050fb4c75bcbc86a159d5c # v1.2.1

 github.com/golang/protobuf                          aa810b61a9c79d51363740d207bb46cf8e620ed5 # v1.2.0

 github.com/cloudflare/cfssl                         5d63dbd981b5c408effbb58c442d54761ff94fbd # 1.3.2

@@ -131,7 +131,9 @@ func PutTask(tx *bolt.Tx, task *api.Task) error {

 // PutTaskStatus updates the status for the task with id.

 func PutTaskStatus(tx *bolt.Tx, id string, status *api.TaskStatus) error {

-	return withCreateTaskBucketIfNotExists(tx, id, func(bkt *bolt.Bucket) error {

+	// this used to be withCreateTaskBucketIfNotExists, but that could lead

+	// to weird race conditions, and was not necessary.

+	return withTaskBucket(tx, id, func(bkt *bolt.Bucket) error {

 		p, err := proto.Marshal(status)

 		if err != nil {

 			return err

@@ -278,10 +278,15 @@ func reconcileTaskState(ctx context.Context, w *worker, assignments []*api.Assig

 	removeTaskAssignment := func(taskID string) error {

 		ctx := log.WithLogger(ctx, log.G(ctx).WithField("task.id", taskID))

-		if err := SetTaskAssignment(tx, taskID, false); err != nil {

-			log.G(ctx).WithError(err).Error("error setting task assignment in database")

+		// if a task is no longer assigned, then we do not have to keep track

+		// of it. a task will only be unassigned when it is deleted on the

+		// manager. instead of SetTaskAssginment to true, we'll just remove the

+		// task now.

+		if err := DeleteTask(tx, taskID); err != nil {

+			log.G(ctx).WithError(err).Error("error removing de-assigned task")

+			return err

 		}

-		return err

+		return nil

 	}

 	// If this was a complete set of assignments, we're going to remove all the remaining

@@ -500,6 +505,21 @@ func (w *worker) newTaskManager(ctx context.Context, tx *bolt.Tx, task *api.Task

 // updateTaskStatus reports statuses to listeners, read lock must be held.

 func (w *worker) updateTaskStatus(ctx context.Context, tx *bolt.Tx, taskID string, status *api.TaskStatus) error {

 	if err := PutTaskStatus(tx, taskID, status); err != nil {

+		// we shouldn't fail to put a task status. however, there exists the

+		// possibility of a race in which we try to put a task status after the

+		// task has been deleted. because this whole contraption is a careful

+		// dance of too-tightly-coupled concurrent parts, fixing tht race is

+		// fraught with hazards. instead, we'll recognize that it can occur,

+		// log the error, and then ignore it.

+		if err == errTaskUnknown {

+			// log at info level. debug logging in docker is already really

+			// verbose, so many people disable it. the race that causes this

+			// behavior should be very rare, but if it occurs, we should know

+			// about it, because if there is some case where it is _not_ rare,

+			// then knowing about it will go a long way toward debugging.

+			log.G(ctx).Info("attempted to update status for a task that has been removed")

+			return nil

+		}

 		log.G(ctx).WithError(err).Error("failed writing status to disk")

 		return err

 	}