Fixed messaging buffering issue

api/pkg/messaging/internal/natsb/NATS.go

@@ -33,7 +33,7 @@ func (b *NatsBroker) Subscribe(event model.NotificationEvent) (<-chan me.Envelop
 	b.logger.Info("Subscribing to subject", zap.String("subject", subject))
 
 	// Create a bidirectional channel to send messages to
-	messageChan := make(chan me.Envelope)
+	messageChan := make(chan me.Envelope, b.bufferSize)
 
 	b.mu.Lock()
 	defer b.mu.Unlock()

api/pkg/messaging/internal/natsb/broker.go

@@ -20,11 +20,12 @@ import (
 type natsSubscriotions = map[string]*TopicSubscription
 
 type NatsBroker struct {
-	nc        *nats.Conn
-	js        nats.JetStreamContext
-	logger    *zap.Logger
-	topicSubs natsSubscriotions
-	mu        sync.Mutex
+	nc         *nats.Conn
+	js         nats.JetStreamContext
+	logger     *zap.Logger
+	topicSubs  natsSubscriotions
+	mu         sync.Mutex
+	bufferSize int
 }
 
 type envConfig struct {
@@ -32,6 +33,8 @@ type envConfig struct {
 	Port                 int
 }
 
+const defaultConsumerBufferSize = 1024
+
 // loadEnv gathers and validates connection details from environment variables
 // listed in the Settings struct. Invalid or missing values surface as a typed
 // InvalidArgument error so callers can decide how to handle them.
@@ -83,6 +86,10 @@ func NewNatsBroker(logger mlogger.Logger, settings *nc.Settings) (*NatsBroker, e
 	var err error
 	var cfg *envConfig
 	var natsURL string
+	bufferSize := defaultConsumerBufferSize
+	if settings != nil && settings.BufferSize > 0 {
+		bufferSize = settings.BufferSize
+	}
 	if settings != nil && strings.TrimSpace(settings.URLEnv) != "" {
 		urlVal := strings.TrimSpace(os.Getenv(settings.URLEnv))
 		if urlVal != "" {
@@ -123,8 +130,9 @@ func NewNatsBroker(logger mlogger.Logger, settings *nc.Settings) (*NatsBroker, e
 	}
 
 	res := &NatsBroker{
-		logger:    l.Named("nats"),
-		topicSubs: natsSubscriotions{},
+		logger:     l.Named("nats"),
+		topicSubs:  natsSubscriotions{},
+		bufferSize: bufferSize,
 	}
 
 	if res.nc, err = nats.Connect(natsURL, opts...); err != nil {

api/pkg/messaging/internal/natsb/config/config.go

@@ -9,4 +9,5 @@ type Settings struct {
 	NATSName      string `mapstructure:"broker_name" yaml:"broker_name"`
 	MaxReconnects int    `mapstructure:"max_reconnects" yaml:"max_reconnects"`
 	ReconnectWait int    `mapstructure:"reconnect_wait" yaml:"reconnect_wait"`
+	BufferSize    int    `mapstructure:"buffer_size" yaml:"buffer_size"`
 }