backend: calculate max total time for starting

Author: weeco

backend/pkg/api/api.go

@@ -173,7 +173,10 @@ func setDefaultClientProviders(cfg *config.Config, logger *zap.Logger, opts *opt
 
 // Start the API server and block
 func (api *API) Start() {
-	startCtx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
+	// Assume 6s for other initializations and up to max startup time before we cancel
+	// the context and force to return early.
+	maxStartTime := 6*time.Second + api.Cfg.Kafka.Startup.TotalMaxTime()
+	startCtx, cancel := context.WithTimeout(context.Background(), maxStartTime)
 	defer cancel()
 
 	err := api.ConsoleSvc.Start(startCtx)

backend/pkg/config/startup.go

@@ -54,3 +54,25 @@ func (k *ServiceStartupAttemptsOptions) Validate() error {
 
 	return nil
 }
+
+// TotalMaxTime calculates the maximum duration for all retry attempts.
+// It includes a fixed 6-second time for each attempt and the subsequent
+// backoff intervals, which increase by BackoffMultiplier (capped at MaxRetryInterval).
+func (k *ServiceStartupAttemptsOptions) TotalMaxTime() time.Duration {
+	// Assuming each attempt takes 6s before a failure triggers a backoff.
+	totalTime := time.Duration(k.MaxRetries) * 6 * time.Second
+
+	// Calculate cumulative backoff delays for all but the final attempt.
+	backoff := k.RetryInterval
+	for i := 1; i < k.MaxRetries; i++ {
+		totalTime += backoff
+		next := time.Duration(float64(backoff) * k.BackoffMultiplier)
+		if next > k.MaxRetryInterval {
+			backoff = k.MaxRetryInterval
+		} else {
+			backoff = next
+		}
+	}
+
+	return totalTime
+}