X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/44c95f99098fa6c6acbfa82d4b6cbc6015eb6e39..70e5c7a3c6a5860d702d5e5c219dc0f3a3696d35:/sdk/go/dispatch/dispatch.go

diff --git a/sdk/go/dispatch/dispatch.go b/sdk/go/dispatch/dispatch.go
index 356d087a46..4e25ba4f06 100644
--- a/sdk/go/dispatch/dispatch.go
+++ b/sdk/go/dispatch/dispatch.go
@@ -29,6 +29,9 @@ const (
 type Dispatcher struct {
 	Arv *arvadosclient.ArvadosClient
 
+	// Batch size for container queries
+	BatchSize int64
+
 	// Queue polling frequency
 	PollPeriod time.Duration
 
@@ -72,39 +75,78 @@ func (d *Dispatcher) Run(ctx context.Context) error {
 	poll := time.NewTicker(d.PollPeriod)
 	defer poll.Stop()
 
+	if d.BatchSize == 0 {
+		d.BatchSize = 100
+	}
+
 	for {
-		tracked := d.trackedUUIDs()
-		d.checkForUpdates([][]interface{}{
-			{"uuid", "in", tracked}})
-		d.checkForUpdates([][]interface{}{
-			{"locked_by_uuid", "=", d.auth.UUID},
-			{"uuid", "not in", tracked}})
-		d.checkForUpdates([][]interface{}{
-			{"state", "=", Queued},
-			{"priority", ">", "0"},
-			{"uuid", "not in", tracked}})
 		select {
 		case <-poll.C:
-			continue
+			break
 		case <-ctx.Done():
 			return ctx.Err()
 		}
-	}
-}
 
-func (d *Dispatcher) trackedUUIDs() []string {
-	d.mtx.Lock()
-	defer d.mtx.Unlock()
-	if len(d.trackers) == 0 {
-		// API bug: ["uuid", "not in", []] does not work as
-		// expected, but this does:
-		return []string{"this-uuid-does-not-exist"}
-	}
-	uuids := make([]string, 0, len(d.trackers))
-	for x := range d.trackers {
-		uuids = append(uuids, x)
+		todo := make(map[string]*runTracker)
+		d.mtx.Lock()
+		// Make a copy of trackers
+		for uuid, tracker := range d.trackers {
+			todo[uuid] = tracker
+		}
+		d.mtx.Unlock()
+
+		// Containers I currently own (Locked/Running)
+		querySuccess := d.checkForUpdates([][]interface{}{
+			{"locked_by_uuid", "=", d.auth.UUID}}, todo)
+
+		// Containers I should try to dispatch
+		querySuccess = d.checkForUpdates([][]interface{}{
+			{"state", "=", Queued},
+			{"priority", ">", "0"}}, todo) && querySuccess
+
+		if !querySuccess {
+			// There was an error in one of the previous queries,
+			// we probably didn't get updates for all the
+			// containers we should have.  Don't check them
+			// individually because it may be expensive.
+			continue
+		}
+
+		// Containers I know about but didn't fall into the
+		// above two categories (probably Complete/Cancelled)
+		var missed []string
+		for uuid := range todo {
+			missed = append(missed, uuid)
+		}
+
+		for len(missed) > 0 {
+			var batch []string
+			if len(missed) > 20 {
+				batch = missed[0:20]
+				missed = missed[20:]
+			} else {
+				batch = missed
+				missed = missed[0:0]
+			}
+			querySuccess = d.checkForUpdates([][]interface{}{
+				{"uuid", "in", batch}}, todo) && querySuccess
+		}
+
+		if !querySuccess {
+			// There was an error in one of the previous queries, we probably
+			// didn't see all the containers we should have, so don't shut down
+			// the missed containers.
+			continue
+		}
+
+		// Containers that I know about that didn't show up in any
+		// query should be let go.
+		for uuid, tracker := range todo {
+			log.Printf("Container %q not returned by any query, stopping tracking.", uuid)
+			tracker.close()
+		}
+
 	}
-	return uuids
 }
 
 // Start a runner in a new goroutine, and send the initial container
@@ -114,7 +156,8 @@ func (d *Dispatcher) start(c arvados.Container) *runTracker {
 	tracker.updates <- c
 	go func() {
 		d.RunContainer(d, c, tracker.updates)
-
+		// RunContainer blocks for the lifetime of the container.  When
+		// it returns, the tracker should delete itself.
 		d.mtx.Lock()
 		delete(d.trackers, c.UUID)
 		d.mtx.Unlock()
@@ -122,25 +165,48 @@ func (d *Dispatcher) start(c arvados.Container) *runTracker {
 	return tracker
 }
 
-func (d *Dispatcher) checkForUpdates(filters [][]interface{}) {
+func (d *Dispatcher) checkForUpdates(filters [][]interface{}, todo map[string]*runTracker) bool {
+	var countList arvados.ContainerList
 	params := arvadosclient.Dict{
 		"filters": filters,
+		"count":   "exact",
+		"limit":   0,
 		"order":   []string{"priority desc"}}
-
-	var list arvados.ContainerList
-	for offset, more := 0, true; more; offset += len(list.Items) {
+	err := d.Arv.List("containers", params, &countList)
+	if err != nil {
+		log.Printf("error getting count of containers: %q", err)
+		return false
+	}
+	itemsAvailable := countList.ItemsAvailable
+	params = arvadosclient.Dict{
+		"filters": filters,
+		"count":   "none",
+		"limit":   d.BatchSize,
+		"order":   []string{"priority desc"}}
+	offset := 0
+	for {
 		params["offset"] = offset
+
+		// This list variable must be a new one declared
+		// inside the loop: otherwise, items in the API
+		// response would get deep-merged into the items
+		// loaded in previous iterations.
+		var list arvados.ContainerList
+
 		err := d.Arv.List("containers", params, &list)
 		if err != nil {
 			log.Printf("Error getting list of containers: %q", err)
-			return
+			return false
+		}
+		d.checkListForUpdates(list.Items, todo)
+		offset += len(list.Items)
+		if len(list.Items) == 0 || itemsAvailable <= offset {
+			return true
 		}
-		more = len(list.Items) > 0 && list.ItemsAvailable > len(list.Items)+offset
-		d.checkListForUpdates(list.Items)
 	}
 }
 
-func (d *Dispatcher) checkListForUpdates(containers []arvados.Container) {
+func (d *Dispatcher) checkListForUpdates(containers []arvados.Container, todo map[string]*runTracker) {
 	d.mtx.Lock()
 	defer d.mtx.Unlock()
 	if d.trackers == nil {
@@ -149,6 +215,8 @@ func (d *Dispatcher) checkListForUpdates(containers []arvados.Container) {
 
 	for _, c := range containers {
 		tracker, alreadyTracking := d.trackers[c.UUID]
+		delete(todo, c.UUID)
+
 		if c.LockedByUUID != "" && c.LockedByUUID != d.auth.UUID {
 			log.Printf("debug: ignoring %s locked by %s", c.UUID, c.LockedByUUID)
 		} else if alreadyTracking {