Only use boost workers for leveldb shadow queues (#15696)

* The leveldb shadow queue of a persistable channel queue should always start with 0
workers and just use boost to add additional workers if necessary.

* create a zero boost so that if there are no workers in a pool - boost to start the workers

* actually set timeout appropriately on boosted workers

Signed-off-by: Andrew Thornton <art27@cantab.net>

Author: zeripath

modules/queue/queue_disk_channel.go

@@ -75,10 +75,10 @@ func NewPersistableChannelQueue(handle HandlerFunc, cfg, exemplar interface{}) (
 				BatchLength:  config.BatchLength,
 				BlockTimeout: 1 * time.Second,
 				BoostTimeout: 5 * time.Minute,
-				BoostWorkers: 5,
-				MaxWorkers:   6,
+				BoostWorkers: 1,
+				MaxWorkers:   5,
 			},
-			Workers: 1,
+			Workers: 0,
 			Name:    config.Name + "-level",
 		},
 		DataDir: config.DataDir,

modules/queue/unique_queue_disk_channel.go

@@ -73,12 +73,12 @@ func NewPersistableChannelUniqueQueue(handle HandlerFunc, cfg, exemplar interfac
 			WorkerPoolConfiguration: WorkerPoolConfiguration{
 				QueueLength:  config.QueueLength,
 				BatchLength:  config.BatchLength,
-				BlockTimeout: 0,
-				BoostTimeout: 0,
-				BoostWorkers: 0,
-				MaxWorkers:   1,
+				BlockTimeout: 1 * time.Second,
+				BoostTimeout: 5 * time.Minute,
+				BoostWorkers: 1,
+				MaxWorkers:   5,
 			},
-			Workers: 1,
+			Workers: 0,
 			Name:    config.Name + "-level",
 		},
 		DataDir: config.DataDir,

modules/queue/workerpool.go

@@ -70,14 +70,52 @@ func (p *WorkerPool) Push(data Data) {
 	atomic.AddInt64(&p.numInQueue, 1)
 	p.lock.Lock()
 	if p.blockTimeout > 0 && p.boostTimeout > 0 && (p.numberOfWorkers <= p.maxNumberOfWorkers || p.maxNumberOfWorkers < 0) {
-		p.lock.Unlock()
+		if p.numberOfWorkers == 0 {
+			p.zeroBoost()
+		} else {
+			p.lock.Unlock()
+		}
 		p.pushBoost(data)
 	} else {
 		p.lock.Unlock()
 		p.dataChan <- data
 	}
 }
 
+func (p *WorkerPool) zeroBoost() {
+	ctx, cancel := context.WithCancel(p.baseCtx)
+	mq := GetManager().GetManagedQueue(p.qid)
+	boost := p.boostWorkers
+	if (boost+p.numberOfWorkers) > p.maxNumberOfWorkers && p.maxNumberOfWorkers >= 0 {
+		boost = p.maxNumberOfWorkers - p.numberOfWorkers
+	}
+	if mq != nil {
+		log.Warn("WorkerPool: %d (for %s) has zero workers - adding %d temporary workers for %s", p.qid, mq.Name, boost, p.boostTimeout)
+
+		start := time.Now()
+		pid := mq.RegisterWorkers(boost, start, true, start.Add(p.boostTimeout), cancel, false)
+		go func() {
+			select {
+			case <-ctx.Done():
+			case <-time.After(p.boostTimeout):
+			}
+			mq.RemoveWorkers(pid)
+			cancel()
+		}()
+	} else {
+		log.Warn("WorkerPool: %d has zero workers - adding %d temporary workers for %s", p.qid, p.boostWorkers, p.boostTimeout)
+		go func() {
+			select {
+			case <-ctx.Done():
+			case <-time.After(p.boostTimeout):
+			}
+			cancel()
+		}()
+	}
+	p.lock.Unlock()
+	p.addWorkers(ctx, boost)
+}
+
 func (p *WorkerPool) pushBoost(data Data) {
 	select {
 	case p.dataChan <- data:
@@ -112,7 +150,7 @@ func (p *WorkerPool) pushBoost(data Data) {
 				log.Warn("WorkerPool: %d (for %s) Channel blocked for %v - adding %d temporary workers for %s, block timeout now %v", p.qid, mq.Name, ourTimeout, boost, p.boostTimeout, p.blockTimeout)
 
 				start := time.Now()
-				pid := mq.RegisterWorkers(boost, start, false, start, cancel, false)
+				pid := mq.RegisterWorkers(boost, start, true, start.Add(p.boostTimeout), cancel, false)
 				go func() {
 					<-ctx.Done()
 					mq.RemoveWorkers(pid)