Add option to configure task check interval

processor.go

@@ -37,6 +37,7 @@ type processor struct {
 	// orderedQueues is set only in strict-priority mode.
 	orderedQueues []string
 
+	taskCheckInterval time.Duration
 	retryDelayFunc    RetryDelayFunc
 	isFailureFunc     func(error) bool
 
@@ -76,6 +77,7 @@ type processorParams struct {
 	broker            base.Broker
 	baseCtxFn         func() context.Context
 	retryDelayFunc    RetryDelayFunc
+	taskCheckInterval time.Duration
 	isFailureFunc     func(error) bool
 	syncCh            chan<- *syncRequest
 	cancelations      *base.Cancelations
@@ -102,6 +104,7 @@ func newProcessor(params processorParams) *processor {
 		clock:             timeutil.NewRealClock(),
 		queueConfig:       queues,
 		orderedQueues:     orderedQueues,
+		taskCheckInterval: params.taskCheckInterval,
 		retryDelayFunc:    params.retryDelayFunc,
 		isFailureFunc:     params.isFailureFunc,
 		syncRequestCh:     params.syncCh,
@@ -178,7 +181,7 @@ func (p *processor) exec() {
 			// Sleep to avoid slamming redis and let scheduler move tasks into queues.
 			// Note: We are not using blocking pop operation and polling queues instead.
 			// This adds significant load to redis.
-			time.Sleep(time.Second)
+			time.Sleep(p.taskCheckInterval)
 			<-p.sema // release token
 			return
 		case err != nil:

processor_test.go

@@ -67,6 +67,7 @@ func newProcessorForTest(t *testing.T, r *rdb.RDB, h Handler) *processor {
 		broker:            r,
 		baseCtxFn:         context.Background,
 		retryDelayFunc:    DefaultRetryDelayFunc,
+		taskCheckInterval: defaultTaskCheckInterval,
 		isFailureFunc:     defaultIsFailureFunc,
 		syncCh:            syncCh,
 		cancelations:      base.NewCancelations(),
@@ -542,6 +543,7 @@ func TestProcessorWithExpiredLease(t *testing.T) {
 			logger:            testLogger,
 			broker:            rdbClient,
 			baseCtxFn:         context.Background,
+			taskCheckInterval: defaultTaskCheckInterval,
 			retryDelayFunc:    DefaultRetryDelayFunc,
 			isFailureFunc:     defaultIsFailureFunc,
 			syncCh:            syncCh,
@@ -696,6 +698,7 @@ func TestProcessorWithStrictPriority(t *testing.T) {
 			logger:            testLogger,
 			broker:            rdbClient,
 			baseCtxFn:         context.Background,
+			taskCheckInterval: defaultTaskCheckInterval,
 			retryDelayFunc:    DefaultRetryDelayFunc,
 			isFailureFunc:     defaultIsFailureFunc,
 			syncCh:            syncCh,

server.go

@@ -15,10 +15,10 @@ import (
 	"sync"
 	"time"
 
-	"github.com/redis/go-redis/v9"
 	"github.com/hibiken/asynq/internal/base"
 	"github.com/hibiken/asynq/internal/log"
 	"github.com/hibiken/asynq/internal/rdb"
+	"github.com/redis/go-redis/v9"
 )
 
 // Server is responsible for task processing and task lifecycle management.
@@ -104,6 +104,15 @@ type Config struct {
 	// If this is defined, then it MUST return a non-nil context
 	BaseContext func() context.Context
 
+	// TaskCheckInterval specifies the interval between checks for new tasks to process when all queues are empty.
+	//
+	// Be careful not to set this value too low because it adds significant load to redis.
+	//
+	// If set to a zero or negative value, NewServer will overwrite the value with default value.
+	//
+	// By default, TaskCheckInterval is set to 1 seconds.
+	TaskCheckInterval time.Duration
+
 	// Function to calculate retry delay for a failed task.
 	//
 	// By default, it uses exponential backoff algorithm to calculate the delay.
@@ -390,6 +399,8 @@ var defaultQueueConfig = map[string]int{
 }
 
 const (
+	defaultTaskCheckInterval = 1 * time.Second
+
 	defaultShutdownTimeout = 8 * time.Second
 
 	defaultHealthCheckInterval = 15 * time.Second
@@ -414,6 +425,12 @@ func NewServer(r RedisConnOpt, cfg Config) *Server {
 	if n < 1 {
 		n = runtime.NumCPU()
 	}
+
+	taskCheckInterval := cfg.TaskCheckInterval
+	if taskCheckInterval <= 0 {
+		taskCheckInterval = defaultTaskCheckInterval
+	}
+
 	delayFunc := cfg.RetryDelayFunc
 	if delayFunc == nil {
 		delayFunc = DefaultRetryDelayFunc
@@ -503,6 +520,7 @@ func NewServer(r RedisConnOpt, cfg Config) *Server {
 		logger:            logger,
 		broker:            rdb,
 		retryDelayFunc:    delayFunc,
+		taskCheckInterval: taskCheckInterval,
 		baseCtxFn:         baseCtxFn,
 		isFailureFunc:     isFailureFunc,
 		syncCh:            syncCh,