Exploring Mule 4's WebSocket Connector

This guide will show you how to use Mule 4’s Web Socket connector to make a full client-server app using the Web socket protocol. But first, let’s understand what a web socket is.

A Web Socket is like having a phone conversation where both parties can speak and listen at any time, unlike sending letters where communication is one-way. It stays connected until someone hangs up. Initially, the connection is made through dialing a number (HTTP), and then it switches to a direct line (TCP) for the ongoing conversation.

Integration Capabilities of a Web Socket Connector:

• Enabling Server Push Alerts: It allows for implementing server push alerts, ensuring timely notifications to clients without constant polling.
• Facilitating Full-Duplex Communication: Web Socket connectors support bidirectional communication between servers and clients, allowing data to be sent and received simultaneously.
• Seamless Integration with Existing HTTP Infrastructure: They can work smoothly over existing HTTP setups without requiring significant changes or additional infrastructure.
• Reducing Server Load: By eliminating the need for clients to repeatedly check the server for updates, Web Socket connections help reduce server load and improve efficiency.

 

Scenarios for Utilizing Web Socket Connector:

• Real-Time Customer Support: Websites offering real-time customer support through chat applications can benefit from Web Socket connectors, ensuring instant communication between agents and users.
• Supply Chain Management: In supply chain management systems, Web Socket connections can facilitate real-time tracking of shipments, inventory updates, and order processing.
• Remote Collaboration Tools: Platforms for remote collaboration, such as virtual whiteboards or brainstorming sessions, leverage Web Socket technology to enable seamless real-time collaboration among distributed teams.
• Healthcare Monitoring Systems: Web Socket connections are utilized in healthcare monitoring systems to enable real-time transmission of patient data from medical devices to central monitoring stations, ensuring prompt intervention in case of emergencies.
• Transportation and Logistics: Applications in transportation and logistics, such as vehicle tracking systems, utilize Web Socket connections to provide real-time updates on vehicle locations, routes, and delivery statuses.
• Weather Forecasting: Weather forecasting applications can employ Web Socket connections to deliver real-time weather updates and alerts to users, ensuring timely information about changing weather conditions.
• E-learning Platforms: Platforms offering live online classes or interactive learning experiences utilize Web Socket technology to facilitate real-time interaction between instructors and students, fostering engaging and immersive learning environments.
• Smart Home Automation: Web Socket connections enable smart home devices to communicate with each other and with central control systems in real time, allowing for seamless automation and remote control of home appliances and systems.
• Emergency Response Systems: Emergency response systems use Web Socket connections to transmit real-time alerts, updates, and instructions to first responders and emergency management personnel during crisis situations, ensuring efficient coordination and response.
• Virtual Events and Conferences: Virtual events and conferences utilize Web Socket technology to provide real-time streaming of sessions, interactive Q&A sessions, and networking opportunities for attendees, offering a rich and engaging online experience.

Scenario:

We're setting up a basic system with two clients and a server. Each client will request updates from the server, and since we can't replicate live data, the server will send a simulated update every 10 seconds.

We'll build two Mulesoft applications: one for the client and one for the server.

For this tutorial, we're using insecure WebSocket (ws).

 

Build a Server Application

• Establish a flow for handling new client connections. To do this, the client should access ws://localhost:8081/wsserver/livescore.
• Employ the "On New Inbound Connection" WebSocket connector.
• For instance, if the header provided by the client doesn't meet the specified condition attributes, terminate the connection using the "Close Socket" WebSocket connector.
• Employ the "Send" WebSocket connection to transmit a success response to the client.

• Set Up the Subscription Flow for Live Scores Only subscribed clients will receive live match scores from the server.
• To receive messages from clients, utilize the "On New Inbound Message" WebSocket connector..
• Store the Socket ID sent by the client in the object store. This will be needed later to deliver the feed to the respective client

 

• In this scenario, we'll send static data to all subscribers using their Object store socket IDs.
• To send a message to a subscriber using their socket ID, utilize the "Send" WebSocket connection.

• Once all match score feeds have been delivered to clients, close the socket and clear all data from the object store.
• Close the socket using the "Close Socket" WebSocket connection, specifying the socket ID.

 

Build a Client Application 

• To subscribe for live scores and receive match feeds as soon as the server publishes them, create a client application. 
• Design the flow to establish a new connection (socket) with the server using the "Open outbound socket" WebSocket connector. Save the socket ID in the object store for future use.

 

• Design the following flow to send a match subscription request to the server using the "Send" WebSocket connector.

 

•  Create a flow to listen to the match feed provided by the server using the "On New Outbound Message" trigger.

 

•  Next, run both the Mulesoft applications, "mulesy-websocket-client" and "mulesy-websocket-server", simultaneously.

 

Testing

To initiate the connection, subscription, and receive match feeds, utilize the following HTTP calls in Postman:

For client_name as client5:

http://localhost:8081/connect?client_name=client5

For client_name as client6:

http://localhost:8081/connect?client_name=client6

 

 

To send the subscription request to the server, use the following HTTP call with client_name as client5 and client6:

Make http call in postman collection to trigger the feed from server to all clients

 

In conclusion, our exploration of Mule 4’s WebSocket Connector highlights its crucial role in facilitating smooth real-time communication within applications.

By providing developers with a powerful toolkit for bidirectional data exchange, this connector revolutionizes conventional integration approaches. With its capacity to manage dynamic workflows, facilitate real-time events, and elevate user interactions, Mule 4’s WebSocket Connector stands out as an essential resource for creating modern, responsive, and engaging applications.