Fix some retry issues

admin.go

@@ -207,19 +207,17 @@ func isErrNoController(err error) bool {
 // provided retryable func) up to the maximum number of tries permitted by
 // the admin client configuration
 func (ca *clusterAdmin) retryOnError(retryable func(error) bool, fn func() error) error {
-	var err error
-	for attempt := 0; attempt < ca.conf.Admin.Retry.Max; attempt++ {
-		err = fn()
-		if err == nil || !retryable(err) {
+	for attemptsRemaining := ca.conf.Admin.Retry.Max; ; {
+		err := fn()
+		attemptsRemaining--
+		if err == nil || attemptsRemaining == 0 || !retryable(err) {
 			return err
 		}
 		Logger.Printf(
 			"admin/request retrying after %dms... (%d attempts remaining)\n",
-			ca.conf.Admin.Retry.Backoff/time.Millisecond, ca.conf.Admin.Retry.Max-attempt)
+			ca.conf.Admin.Retry.Backoff/time.Millisecond, attemptsRemaining)
 		time.Sleep(ca.conf.Admin.Retry.Backoff)
-		continue
 	}
-	return err
 }
 
 func (ca *clusterAdmin) CreateTopic(topic string, detail *TopicDetail, validateOnly bool) error {

admin_test.go

@@ -1790,3 +1790,73 @@ func TestDescribeLogDirsUnknownBroker(t *testing.T) {
 		}
 	}
 }
+
+func Test_retryOnError(t *testing.T) {
+	testBackoffTime := 100 * time.Millisecond
+	config := NewTestConfig()
+	config.Version = V1_0_0_0
+	config.Admin.Retry.Max = 3
+	config.Admin.Retry.Backoff = testBackoffTime
+
+	admin := &clusterAdmin{conf: config}
+
+	t.Run("immediate success", func(t *testing.T) {
+		startTime := time.Now()
+		attempts := 0
+		err := admin.retryOnError(
+			func(error) bool { return true },
+			func() error {
+				attempts++
+				return nil
+			})
+		if err != nil {
+			t.Fatalf("expected no error but was %v", err)
+		}
+		if attempts != 1 {
+			t.Fatalf("expected 1 attempt to have been made but was %d", attempts)
+		}
+		if time.Since(startTime) >= testBackoffTime {
+			t.Fatalf("single attempt should take less than backoff time")
+		}
+	})
+
+	t.Run("immediate failure", func(t *testing.T) {
+		startTime := time.Now()
+		attempts := 0
+		err := admin.retryOnError(
+			func(error) bool { return false },
+			func() error {
+				attempts++
+				return errors.New("mock error")
+			})
+		if err == nil {
+			t.Fatalf("expected error but was nil")
+		}
+		if attempts != 1 {
+			t.Fatalf("expected 1 attempt to have been made but was %d", attempts)
+		}
+		if time.Since(startTime) >= testBackoffTime {
+			t.Fatalf("single attempt should take less than backoff time")
+		}
+	})
+
+	t.Run("failing all attempts", func(t *testing.T) {
+		startTime := time.Now()
+		attempts := 0
+		err := admin.retryOnError(
+			func(error) bool { return true },
+			func() error {
+				attempts++
+				return errors.New("mock error")
+			})
+		if err == nil {
+			t.Errorf("expected error but was nil")
+		}
+		if attempts != 3 {
+			t.Errorf("expected 3 attempts to have been made but was %d", attempts)
+		}
+		if time.Since(startTime) >= 3*testBackoffTime {
+			t.Errorf("attempt+sleep+attempt+sleep+attempt should take less than 3 * backoff time")
+		}
+	})
+}

client.go

@@ -979,9 +979,10 @@ func (client *client) tryRefreshMetadata(topics []string, attemptsRemaining int,
 			if time.Since(time.Unix(t/1e3, 0)) < backoff {
 				return err
 			}
+			attemptsRemaining--
 			Logger.Printf("client/metadata retrying after %dms... (%d attempts remaining)\n", backoff/time.Millisecond, attemptsRemaining)
 
-			return client.tryRefreshMetadata(topics, attemptsRemaining-1, deadline)
+			return client.tryRefreshMetadata(topics, attemptsRemaining, deadline)
 		}
 		return err
 	}
@@ -1160,9 +1161,10 @@ func (client *client) findCoordinator(coordinatorKey string, coordinatorType Coo
 	retry := func(err error) (*FindCoordinatorResponse, error) {
 		if attemptsRemaining > 0 {
 			backoff := client.computeBackoff(attemptsRemaining)
+			attemptsRemaining--
 			Logger.Printf("client/coordinator retrying after %dms... (%d attempts remaining)\n", backoff/time.Millisecond, attemptsRemaining)
 			time.Sleep(backoff)
-			return client.findCoordinator(coordinatorKey, coordinatorType, attemptsRemaining-1)
+			return client.findCoordinator(coordinatorKey, coordinatorType, attemptsRemaining)
 		}
 		return nil, err
 	}