better error handling

Author: asim

broker/http_broker.go

@@ -533,7 +533,7 @@ func (h *httpBroker) Publish(topic string, msg *Message, opts ...PublishOption)
 	}
 	h.RUnlock()
 
-	pub := func(node *registry.Node, t string, b []byte) {
+	pub := func(node *registry.Node, t string, b []byte) error {
 		scheme := "http"
 
 		// check if secure is added in metadata
@@ -547,14 +547,13 @@ func (h *httpBroker) Publish(topic string, msg *Message, opts ...PublishOption)
 		uri := fmt.Sprintf("%s://%s:%d%s?%s", scheme, node.Address, node.Port, DefaultSubPath, vals.Encode())
 		r, err := h.c.Post(uri, "application/json", bytes.NewReader(b))
 		if err != nil {
-			// save on error
-			h.saveMessage(t, b)
-			return
+			return err
 		}
 
 		// discard response body
 		io.Copy(ioutil.Discard, r.Body)
 		r.Body.Close()
+		return nil
 	}
 
 	srv := func(s []*registry.Service, b []byte) {
@@ -567,16 +566,29 @@ func (h *httpBroker) Publish(topic string, msg *Message, opts ...PublishOption)
 			switch service.Version {
 			// broadcast version means broadcast to all nodes
 			case broadcastVersion:
+				var success bool
+
+				// publish to all nodes
 				for _, node := range service.Nodes {
 					// publish async
-					pub(node, topic, b)
+					if err := pub(node, topic, b); err == nil {
+						success = true
+					}
+				}
+
+				// save if it failed to publish at least once
+				if !success {
+					h.saveMessage(topic, b)
 				}
 			default:
 				// select node to publish to
 				node := service.Nodes[rand.Int()%len(service.Nodes)]
 
-				// publish async
-				pub(node, topic, b)
+				// publish async to one node
+				if err := pub(node, topic, b); err != nil {
+					// if failed save it
+					h.saveMessage(topic, b)
+				}
 			}
 		}
 	}