feat: implement jitter in backoff handling

- Add Jitter field to Message struct for randomizing backoff steps
- Include jitter in Options struct and NewOptions function
- Add Bool helper function for allocating new bool values
- Update TestOptions to include Jitter and assert its value
- Add Jitter to Queue's handle function

Signed-off-by: appleboy <appleboy.tw@gmail.com>

Author: appleboy

job/job.go

@@ -46,6 +46,9 @@ type Message struct {
 	// Defaults to 10 seconds.
 	RetryMax time.Duration `json:"retry_max"`
 
+	// Jitter eases contention by randomizing backoff steps
+	Jitter bool `json:"jitter"`
+
 	// Data to save Unsafe cast
 	Data []byte
 }

job/option.go

@@ -9,6 +9,7 @@ type Options struct {
 	retryFactor float64
 	retryMin    time.Duration
 	retryMax    time.Duration
+	jitter      bool
 
 	timeout time.Duration
 }
@@ -22,6 +23,7 @@ func newDefaultOptions() Options {
 		retryMin:    100 * time.Millisecond,
 		retryMax:    10 * time.Second,
 		timeout:     60 * time.Minute,
+		jitter:      false,
 	}
 }
 
@@ -32,6 +34,7 @@ type AllowOption struct {
 	RetryFactor *float64
 	RetryMin    *time.Duration
 	RetryMax    *time.Duration
+	Jitter      *bool
 	Timeout     *time.Duration
 }
 
@@ -63,6 +66,10 @@ func NewOptions(opts ...AllowOption) Options {
 		if opts[0].RetryMax != nil && *opts[0].RetryMax != o.retryMax {
 			o.retryMax = *opts[0].RetryMax
 		}
+
+		if opts[0].Jitter != nil && *opts[0].Jitter != o.jitter {
+			o.jitter = *opts[0].Jitter
+		}
 	}
 
 	return o
@@ -82,3 +89,8 @@ func Float64(val float64) *float64 {
 func Time(v time.Duration) *time.Duration {
 	return &v
 }
+
+// Bool is a helper routine that allocates a new bool value
+func Bool(val bool) *bool {
+	return &val
+}

job/option_test.go

@@ -14,6 +14,7 @@ func TestOptions(t *testing.T) {
 			RetryCount: Int64(100),
 			RetryDelay: Time(30 * time.Millisecond),
 			Timeout:    Time(3 * time.Millisecond),
+			Jitter:     Bool(true),
 		},
 	)
 
@@ -23,4 +24,5 @@ func TestOptions(t *testing.T) {
 	assert.Equal(t, 100*time.Millisecond, o.retryMin)
 	assert.Equal(t, 10*time.Second, o.retryMax)
 	assert.Equal(t, 2.0, o.retryFactor)
+	assert.True(t, o.jitter)
 }

queue.go

@@ -203,6 +203,7 @@ func (q *Queue) handle(m *job.Message) error {
 			Min:    m.RetryMin,
 			Max:    m.RetryMax,
 			Factor: m.RetryFactor,
+			Jitter: m.Jitter,
 		}
 		delay := m.RetryDelay
 	loop: