v0.18.3

CHANGELOG.md

@@ -7,7 +7,34 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-## [0.18.2] - 2021-06-29
+## [0.18.3] - 2020-08-09
+
+### Changed
+
+- `Client.Enqueue` no longer enqueues tasks with empty typename; Error message is returned.
+
+## [0.18.2] - 2020-07-15
+
+### Changed
+
+- Changed `Queue` function to not to convert the provided queue name to lowercase. Queue names are now case-sensitive.
+- `QueueInfo.MemoryUsage` is now an approximate usage value.
+
+### Fixed
+
+- Fixed latency issue around memory usage (see https://github.com/hibiken/asynq/issues/309).
+
+## [0.18.1] - 2020-07-04
+
+### Changed
+
+- Changed to execute task recovering logic when server starts up; Previously it needed to wait for a minute for task recovering logic to exeucte.
+
+### Fixed
+
+- Fixed task recovering logic to execute every minute
+
+## [0.18.0] - 2021-06-29
 
 ### Changed
 

README.md

@@ -26,11 +26,10 @@ Task queues are used as a mechanism to distribute work across multiple machines.
 
 - Guaranteed [at least one execution](https://www.cloudcomputingpatterns.org/at_least_once_delivery/) of a task
 - Scheduling of tasks
-- Durability since tasks are written to Redis
 - [Retries](https://github.com/hibiken/asynq/wiki/Task-Retry) of failed tasks
 - Automatic recovery of tasks in the event of a worker crash
-- [Weighted priority queues](https://github.com/hibiken/asynq/wiki/Priority-Queues#weighted-priority-queues)
-- [Strict priority queues](https://github.com/hibiken/asynq/wiki/Priority-Queues#strict-priority-queues)
+- [Weighted priority queues](https://github.com/hibiken/asynq/wiki/Queue-Priority#weighted-priority)
+- [Strict priority queues](https://github.com/hibiken/asynq/wiki/Queue-Priority#strict-priority)
 - Low latency to add a task since writes are fast in Redis
 - De-duplication of tasks using [unique option](https://github.com/hibiken/asynq/wiki/Unique-Tasks)
 - Allow [timeout and deadline per task](https://github.com/hibiken/asynq/wiki/Task-Timeout-and-Cancelation)
@@ -58,7 +57,7 @@ Initialize your project by creating a folder and then running `go mod init githu
 go get -u github.com/hibiken/asynq
 ```
 
-Make sure you're running a Redis server locally or from a [Docker](https://hub.docker.com/_/redis) container. Version `3.0` or higher is required.
+Make sure you're running a Redis server locally or from a [Docker](https://hub.docker.com/_/redis) container. Version `4.0` or higher is required.
 
 Next, write a package that encapsulates task creation and task handling.
 
@@ -92,7 +91,7 @@ type ImageResizePayload struct {
 //----------------------------------------------
 
 func NewEmailDeliveryTask(userID int, tmplID string) (*asynq.Task, error) {
-    payload, err := json.Marshal(EmailDeliveryPayload{UserID: userID, TemplateID: templID})
+    payload, err := json.Marshal(EmailDeliveryPayload{UserID: userID, TemplateID: tmplID})
     if err != nil {
         return nil, err
     }
@@ -120,7 +119,7 @@ func HandleEmailDeliveryTask(ctx context.Context, t *asynq.Task) error {
     if err := json.Unmarshal(t.Payload(), &p); err != nil {
         return fmt.Errorf("json.Unmarshal failed: %v: %w", err, asynq.SkipRetry)
     }
-    log.Printf("Sending Email to User: user_id = %d, template_id = %s\n", p.UserID, p.TemplateID)
+    log.Printf("Sending Email to User: user_id=%d, template_id=%s", p.UserID, p.TemplateID)
     // Email delivery code ...
     return nil
 }
@@ -130,28 +129,27 @@ type ImageProcessor struct {
     // ... fields for struct
 }
 
-func (p *ImageProcessor) ProcessTask(ctx context.Context, t *asynq.Task) error {
+func (processor *ImageProcessor) ProcessTask(ctx context.Context, t *asynq.Task) error {
     var p ImageResizePayload
     if err := json.Unmarshal(t.Payload(), &p); err != nil {
         return fmt.Errorf("json.Unmarshal failed: %v: %w", err, asynq.SkipRetry)
     }
-    log.Printf("Resizing image: src = %s\n", p.SourceURL)
+    log.Printf("Resizing image: src=%s", p.SourceURL)
     // Image resizing code ...
     return nil
 }
 
 func NewImageProcessor() *ImageProcessor {
-    // ... return an instance
+	return &ImageProcessor{}
 }
 ```
 
-In your application code, import the above package and use [`Client`](https://pkg.go.dev/github.com/hibiken/asynq?tab=doc#Client) to put tasks on the queue.
+In your application code, import the above package and use [`Client`](https://pkg.go.dev/github.com/hibiken/asynq?tab=doc#Client) to put tasks on queues.
 
 ```go
 package main
 
 import (
-    "fmt"
     "log"
     "time"
 
@@ -178,7 +176,7 @@ func main() {
     if err != nil {
         log.Fatalf("could not enqueue task: %v", err)
     }
-    fmt.Printf("enqueued task: id=%s queue=%s\n", info.ID, info.Queue)
+    log.Printf("enqueued task: id=%s queue=%s", info.ID, info.Queue)
 
 
     // ------------------------------------------------------------
@@ -190,7 +188,7 @@ func main() {
     if err != nil {
         log.Fatalf("could not schedule task: %v", err)
     }
-    fmt.Printf("enqueued task: id=%s queue=%s\n", info.ID, info.Queue)
+    log.Printf("enqueued task: id=%s queue=%s", info.ID, info.Queue)
 
 
     // ----------------------------------------------------------------------------
@@ -208,7 +206,7 @@ func main() {
     if err != nil {
         log.Fatalf("could not enqueue task: %v", err)
     }
-    fmt.Printf("enqueued task: id=%s queue=%s\n", info.ID, info.Queue)
+    log.Printf("enqueued task: id=%s queue=%s", info.ID, info.Queue)
 
     // ---------------------------------------------------------------------------
     // Example 4: Pass options to tune task processing behavior at enqueue time.
@@ -219,7 +217,7 @@ func main() {
     if err != nil {
         log.Fatal("could not enqueue task: %v", err)
     }
-    fmt.Printf("enqueued task: id=%s queue=%s\n", info.ID, info.Queue)
+    log.Printf("enqueued task: id=%s queue=%s", info.ID, info.Queue)
 }
 ```
 

client.go

@@ -93,10 +93,8 @@ func (n retryOption) Type() OptionType   { return MaxRetryOpt }
 func (n retryOption) Value() interface{} { return int(n) }
 
 // Queue returns an option to specify the queue to enqueue the task into.
-//
-// Queue name is case-insensitive and the lowercased version is used.
 func Queue(qname string) Option {
-	return queueOption(strings.ToLower(qname))
+	return queueOption(qname)
 }
 
 func (qname queueOption) String() string     { return fmt.Sprintf("Queue(%q)", string(qname)) }
@@ -207,11 +205,11 @@ func composeOptions(opts ...Option) (option, error) {
 		case retryOption:
 			res.retry = int(opt)
 		case queueOption:
-			trimmed := strings.TrimSpace(string(opt))
-			if err := base.ValidateQueueName(trimmed); err != nil {
+			qname := string(opt)
+			if err := base.ValidateQueueName(qname); err != nil {
 				return option{}, err
 			}
-			res.queue = trimmed
+			res.queue = qname
 		case timeoutOption:
 			res.timeout = time.Duration(opt)
 		case deadlineOption:
@@ -269,6 +267,9 @@ func (c *Client) Close() error {
 //
 // If no ProcessAt or ProcessIn options are provided, the task will be pending immediately.
 func (c *Client) Enqueue(task *Task, opts ...Option) (*TaskInfo, error) {
+	if strings.TrimSpace(task.Type()) == "" {
+		return nil, fmt.Errorf("task typename cannot be empty")
+	}
 	c.mu.Lock()
 	if defaults, ok := c.opts[task.Type()]; ok {
 		opts = append(defaults, opts...)

client_test.go

@@ -287,13 +287,13 @@ func TestClientEnqueue(t *testing.T) {
 			},
 		},
 		{
-			desc: "Queue option should be case-insensitive",
+			desc: "Queue option should be case sensitive",
 			task: task,
 			opts: []Option{
-				Queue("HIGH"),
+				Queue("MyQueue"),
 			},
 			wantInfo: &TaskInfo{
-				Queue:         "high",
+				Queue:         "MyQueue",
 				Type:          task.Type(),
 				Payload:       task.Payload(),
 				State:         TaskStatePending,
@@ -306,12 +306,12 @@ func TestClientEnqueue(t *testing.T) {
 				NextProcessAt: now,
 			},
 			wantPending: map[string][]*base.TaskMessage{
-				"high": {
+				"MyQueue": {
 					{
 						Type:     task.Type(),
 						Payload:  task.Payload(),
 						Retry:    defaultMaxRetry,
-						Queue:    "high",
+						Queue:    "MyQueue",
 						Timeout:  int64(defaultTimeout.Seconds()),
 						Deadline: noDeadline.Unix(),
 					},
@@ -585,6 +585,16 @@ func TestClientEnqueueError(t *testing.T) {
 				Queue(""),
 			},
 		},
+		{
+			desc: "With empty task typename",
+			task: NewTask("", h.JSON(map[string]interface{}{})),
+			opts: []Option{},
+		},
+		{
+			desc: "With blank task typename",
+			task: NewTask("    ", h.JSON(map[string]interface{}{})),
+			opts: []Option{},
+		},
 	}
 
 	for _, tc := range tests {

inspector.go

@@ -50,6 +50,7 @@ type QueueInfo struct {
 	Queue string
 
 	// Total number of bytes that the queue and its tasks require to be stored in redis.
+	// It is an approximate memory usage value in bytes since the value is computed by sampling.
 	MemoryUsage int64
 
 	// Size is the total number of tasks in the queue.

internal/base/base.go

@@ -10,6 +10,7 @@ import (
 	"crypto/md5"
 	"encoding/hex"
 	"fmt"
+	"strings"
 	"sync"
 	"time"
 
@@ -22,7 +23,7 @@ import (
 )
 
 // Version of asynq library and CLI.
-const Version = "0.18.0"
+const Version = "0.18.3"
 
 // DefaultQueueName is the queue name used if none are specified by user.
 const DefaultQueueName = "default"
@@ -85,7 +86,7 @@ func TaskStateFromString(s string) (TaskState, error) {
 // ValidateQueueName validates a given qname to be used as a queue name.
 // Returns nil if valid, otherwise returns non-nil error.
 func ValidateQueueName(qname string) error {
-	if len(qname) == 0 {
+	if len(strings.TrimSpace(qname)) == 0 {
 		return fmt.Errorf("queue name must contain one or more characters")
 	}
 	return nil

internal/rdb/inspect.go

@@ -26,7 +26,8 @@ type Stats struct {
 	// Name of the queue (e.g. "default", "critical").
 	Queue string
 	// MemoryUsage is the total number of bytes the queue and its tasks require
-	// to be stored in redis.
+	// to be stored in redis. It is an approximate memory usage value in bytes
+	// since the value is computed by sampling.
 	MemoryUsage int64
 	// Paused indicates whether the queue is paused.
 	// If true, tasks in the queue should not be processed.
@@ -172,31 +173,82 @@ func (r *RDB) CurrentStats(qname string) (*Stats, error) {
 	return stats, nil
 }
 
+// Computes memory usage for the given queue by sampling tasks
+// from each redis list/zset. Returns approximate memory usage value
+// in bytes.
+//
+// KEYS[1] -> asynq:{qname}:active
+// KEYS[2] -> asynq:{qname}:pending
+// KEYS[3] -> asynq:{qname}:scheduled
+// KEYS[4] -> asynq:{qname}:retry
+// KEYS[5] -> asynq:{qname}:archived
+//
+// ARGV[1] -> asynq:{qname}:t:
+// ARGV[2] -> sample_size (e.g 20)
+var memoryUsageCmd = redis.NewScript(`
+local sample_size = tonumber(ARGV[2])
+if sample_size <= 0 then
+    return redis.error_reply("sample size must be a positive number")
+end
+local memusg = 0
+for i=1,2 do
+    local ids = redis.call("LRANGE", KEYS[i], 0, sample_size - 1)
+    local sample_total = 0
+    if (table.getn(ids) > 0) then
+        for _, id in ipairs(ids) do
+            local bytes = redis.call("MEMORY", "USAGE", ARGV[1] .. id)
+            sample_total = sample_total + bytes
+        end
+        local n = redis.call("LLEN", KEYS[i])
+        local avg = sample_total / table.getn(ids)
+        memusg = memusg + (avg * n)
+    end
+    local m = redis.call("MEMORY", "USAGE", KEYS[i])
+    if (m) then
+        memusg = memusg + m
+    end
+end
+for i=3,5 do
+    local ids = redis.call("ZRANGE", KEYS[i], 0, sample_size - 1)
+    local sample_total = 0
+    if (table.getn(ids) > 0) then
+        for _, id in ipairs(ids) do
+            local bytes = redis.call("MEMORY", "USAGE", ARGV[1] .. id)
+            sample_total = sample_total + bytes
+        end
+        local n = redis.call("ZCARD", KEYS[i])
+        local avg = sample_total / table.getn(ids)
+        memusg = memusg + (avg * n)
+    end
+    local m = redis.call("MEMORY", "USAGE", KEYS[i])
+    if (m) then
+        memusg = memusg + m
+    end
+end
+return memusg
+`)
+
 func (r *RDB) memoryUsage(qname string) (int64, error) {
 	var op errors.Op = "rdb.memoryUsage"
-	var (
-		keys   []string
-		data   []string
-		cursor uint64
-		err    error
-	)
-	for {
-		data, cursor, err = r.client.Scan(cursor, fmt.Sprintf("asynq:{%s}*", qname), 100).Result()
-		if err != nil {
-			return 0, errors.E(op, errors.Unknown, &errors.RedisCommandError{Command: "scan", Err: err})
-		}
-		keys = append(keys, data...)
-		if cursor == 0 {
-			break
-		}
+	const sampleSize = 20
+	keys := []string{
+		base.ActiveKey(qname),
+		base.PendingKey(qname),
+		base.ScheduledKey(qname),
+		base.RetryKey(qname),
+		base.ArchivedKey(qname),
 	}
-	var usg int64
-	for _, k := range keys {
-		n, err := r.client.MemoryUsage(k).Result()
-		if err != nil {
-			return 0, errors.E(op, errors.Unknown, &errors.RedisCommandError{Command: "memory usage", Err: err})
-		}
-		usg += n
+	argv := []interface{}{
+		base.TaskKeyPrefix(qname),
+		sampleSize,
+	}
+	res, err := memoryUsageCmd.Run(r.client, keys, argv...).Result()
+	if err != nil {
+		return 0, errors.E(op, errors.Unknown, fmt.Sprintf("redis eval error: %v", err))
+	}
+	usg, err := cast.ToInt64E(res)
+	if err != nil {
+		return 0, errors.E(op, errors.Internal, fmt.Sprintf("could not cast script return value to int64"))
 	}
 	return usg, nil
 }

recoverer.go

@@ -57,6 +57,7 @@ func (r *recoverer) start(wg *sync.WaitGroup) {
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
+		r.recover()
 		timer := time.NewTimer(r.interval)
 		for {
 			select {
@@ -65,27 +66,31 @@ func (r *recoverer) start(wg *sync.WaitGroup) {
 				timer.Stop()
 				return
 			case <-timer.C:
-				// Get all tasks which have expired 30 seconds ago or earlier.
-				deadline := time.Now().Add(-30 * time.Second)
-				msgs, err := r.broker.ListDeadlineExceeded(deadline, r.queues...)
-				if err != nil {
-					r.logger.Warn("recoverer: could not list deadline exceeded tasks")
-					continue
-				}
-				const errMsg = "deadline exceeded" // TODO: better error message
-				for _, msg := range msgs {
-					if msg.Retried >= msg.Retry {
-						r.archive(msg, errMsg)
-					} else {
-						r.retry(msg, errMsg)
-					}
-				}
-
+				r.recover()
+				timer.Reset(r.interval)
 			}
 		}
 	}()
 }
 
+func (r *recoverer) recover() {
+	// Get all tasks which have expired 30 seconds ago or earlier.
+	deadline := time.Now().Add(-30 * time.Second)
+	msgs, err := r.broker.ListDeadlineExceeded(deadline, r.queues...)
+	if err != nil {
+		r.logger.Warn("recoverer: could not list deadline exceeded tasks")
+		return
+	}
+	const errMsg = "deadline exceeded"
+	for _, msg := range msgs {
+		if msg.Retried >= msg.Retry {
+			r.archive(msg, errMsg)
+		} else {
+			r.retry(msg, errMsg)
+		}
+	}
+}
+
 func (r *recoverer) retry(msg *base.TaskMessage, errMsg string) {
 	delay := r.retryDelayFunc(msg.Retried, fmt.Errorf(errMsg), NewTask(msg.Type, msg.Payload))
 	retryAt := time.Now().Add(delay)

servemux.go

@@ -98,7 +98,7 @@ func (mux *ServeMux) Handle(pattern string, handler Handler) {
 	mux.mu.Lock()
 	defer mux.mu.Unlock()
 
-	if pattern == "" {
+	if strings.TrimSpace(pattern) == "" {
 		panic("asynq: invalid pattern")
 	}
 	if handler == nil {

server.go

@@ -295,6 +295,9 @@ func NewServer(r RedisConnOpt, cfg Config) *Server {
 	}
 	queues := make(map[string]int)
 	for qname, p := range cfg.Queues {
+		if err := base.ValidateQueueName(qname); err != nil {
+			continue // ignore invalid queue names
+		}
 		if p > 0 {
 			queues[qname] = p
 		}