Push with its Anatomy, Pros, Cons and Examples

In the context of computer science and technology, “push” refers to a mechanism or method for sending data, information, or updates from a server or sender to a client or recipient without the client explicitly requesting it. It’s often associated with real-time or event-driven communication where the server “pushes” data to the client as it becomes available or changes, rather than the client repeatedly “pulling” or requesting updates from the server.

Here are some key points about push technology:

• Real-Time Updates: Push technology is commonly used for delivering real-time updates, notifications, or changes to clients. Examples include chat messages, live sports scores, stock price updates, and social media notifications.
• Event-Driven: Push communication is typically event-driven, meaning the server sends data to clients in response to specific events or changes. Clients subscribe to events of interest, and when those events occur, the server pushes the relevant data to the subscribed clients.
• Reduced Latency: Push technology helps reduce latency because data is sent to clients as soon as it’s available or relevant. Clients don’t need to poll the server repeatedly to check for updates, which can be inefficient and introduce delay.
• Efficient: Push technology is efficient because it minimizes unnecessary network traffic. In a pull-based approach, clients might frequently request data even when there are no updates, whereas push ensures that data is sent only when needed.
• WebSocket and Server-Sent Events (SSE): WebSocket and Server-Sent Events (SSE) are two common technologies used for implementing push communication in web applications. WebSocket provides full-duplex communication channels over a single TCP connection, allowing bidirectional data transfer. SSE, on the other hand, is a one-way communication channel from server to client over HTTP.
• Use Cases: Push technology is used in various applications, including instant messaging, collaborative tools, online gaming, live streaming, financial trading platforms, and IoT (Internet of Things) systems for real-time sensor data updates.
• Pub/Sub (Publish-Subscribe): Pub/Sub is a common architectural pattern used in push systems. Clients subscribe to specific topics or channels, and servers publish messages or updates to those topics. Subscribed clients receive the messages related to the topics they are interested in.
• Push Notifications: On mobile devices, push notifications are a common use of push technology. Servers send notifications to mobile apps even when the apps are not actively in use, allowing apps to provide timely updates and alerts to users.

In summary, push technology enables the server to proactively send data and updates to clients, improving real-time communication, reducing latency, and increasing efficiency compared to traditional pull-based approaches. It is a fundamental concept in building modern, interactive, and real-time applications.

Anatomy of Push

The anatomy of a push mechanism, which allows data or updates to be sent from a server or sender to a client or recipient without the client explicitly requesting it, involves several components and stages. Here’s a breakdown of the key elements in the anatomy of a push system:

• Server: The server is responsible for generating and sending the data or updates to clients. It acts as the source of information and events that need to be pushed to the clients.
• Client: The client is the recipient of the pushed data or updates. It can be a web browser, a mobile app, a desktop application, or any device or software that can receive and process incoming data.
• Subscription: In many push systems, clients must establish a subscription or connection to the server to indicate their interest in receiving specific types of data or updates. Clients subscribe to channels, topics, or events that are relevant to their needs.
• Push Trigger: Push events or triggers are events that occur on the server, signaling the need to send data or updates to one or more clients. These events can be generated by various factors, such as changes in data, incoming messages, system events, or user interactions.
• Push Channel or Topic: Pushed data is often organized into channels, topics, or event categories. Clients can subscribe to specific channels or topics to receive only the data relevant to their interests. For example, in a chat application, clients may subscribe to individual chat rooms or group conversations.
• Communication Protocol: To establish and maintain a push connection, a specific communication protocol is used. Common protocols for push communication include WebSocket, Server-Sent Events (SSE), and MQTT (Message Queuing Telemetry Transport).
• Push Server or Broker: In some cases, a push server or broker may be used as an intermediary between the server and clients. The push server manages client subscriptions, routes messages, and ensures reliable delivery of pushed data.
• Data Payload: The data payload is the actual content being pushed from the server to the client. It can be in various formats, such as JSON, XML, binary data, or plain text, depending on the application’s requirements.
• Push Notification: In mobile and desktop applications, push notifications are a common form of push communication. These are short messages or alerts sent by servers to mobile apps or desktop clients, typically via push notification services provided by operating systems (e.g., Apple Push Notification Service, Firebase Cloud Messaging).
• Client-Side Handling: On the client side, there are mechanisms to receive and process pushed data. This may involve event listeners, callback functions, or other client-specific handling mechanisms to react to incoming updates.
• Error Handling: Push systems often implement error-handling mechanisms to deal with issues like dropped connections, network errors, or server unavailability. Clients may attempt to reconnect or handle errors gracefully to maintain the push communication.
• Security and Authentication: Secure authentication and authorization mechanisms are crucial to ensure that only authorized clients can subscribe to and receive pushed data. Encryption may also be employed to protect the data in transit.

Pros & Cons

Push communication mechanisms, where data or updates are sent from a server or sender to a client or recipient without the client explicitly requesting it, have both advantages (pros) and disadvantages (cons). Here’s a breakdown of the pros and cons of push communication:

Pros of Push Communication:

• Real-Time Updates: Push allows for real-time or near-real-time updates, ensuring that clients receive information as soon as it becomes available or changes. This is valuable for applications that require timely data delivery, such as instant messaging, live sports scores, and stock market updates.
• Reduced Latency: Push reduces latency because data is sent proactively to clients when it’s ready, eliminating the need for clients to poll or request updates at regular intervals. This leads to faster data delivery and a more responsive user experience.
• Efficient Use of Resources: Push communication is more efficient than pull-based approaches because it minimizes unnecessary network traffic. Clients only receive data when it’s relevant, reducing bandwidth consumption and server load.
• Event-Driven: Push is inherently event-driven, allowing applications to respond to specific events or triggers, making it suitable for scenarios where actions are based on changes or events, such as IoT sensor data or collaborative tools.
• Scalability: Push systems are often more scalable because they can handle a large number of concurrent clients without overloading the server. Clients can receive updates in parallel without queuing or waiting.
• Push Notifications: Push is commonly used for sending notifications to mobile and desktop applications, ensuring that users receive important alerts even when the app is not actively in use.
• Streamlined User Experience: Push enhances the user experience by providing continuous updates without the need for user-initiated actions. This is particularly beneficial for social media, news, and live content applications.

Cons of Push Communication:

• Complex Implementation: Building and maintaining push systems can be complex due to the need to manage asynchronous events, concurrency, and potential race conditions. This complexity can lead to more challenging development and debugging.
• Resource Intensive: While push reduces latency, it can be resource-intensive for servers and clients. Servers need to manage multiple connections, and clients may need to handle a significant amount of incoming data, which can strain system resources.
• Error Handling: Handling errors in push systems, such as dropped connections or missed updates, can be challenging. Implementing robust error-handling mechanisms is necessary to ensure reliability.
• Security Concerns: Push systems must implement secure authentication and authorization mechanisms to prevent unauthorized access to data. Encryption may also be needed to protect data in transit.
• Potential Overload: In cases of sudden surges in events or high-frequency updates, push systems may experience overload, leading to performance issues or dropped events. Proper load balancing and throttling mechanisms are essential to manage this.
• Compatibility: Compatibility with older browsers and devices can be an issue, as some older technologies may not support modern push protocols like WebSocket or Server-Sent Events (SSE).
• Privacy Concerns: Push notifications can be intrusive, and users may be concerned about their privacy. Striking the right balance between timely notifications and respecting user preferences is crucial.

In summary, push communication offers significant advantages in terms of real-time updates, reduced latency, and efficient data delivery. However, it also comes with complexities and challenges related to implementation, resource management, and error handling. Careful consideration of the pros and cons is essential when deciding whether to implement push communication in a particular application or system.

Here i am creating a web socket messaging system using push.

const http = require("http");
const WebSocketServer = require("websocket").server;
let connections = [];

const httpserver = http.createServer();

const websocket = new WebSocketServer({"httpServer": httpserver});

httpserver.listen(3000, ()=> console.log("My server is listening on port 3000"));

websocket.on("request", request => {
    const connection = request.accept(null, request.origin);
    connection.on("message", message => {
        connections.forEach(c => c.connected ? c.send(`User${connection.socket.remotePort} says ${message.utf8Data}`) : null);
    });

    connections.push(connection);
    connections.forEach(c=> c.send(`User${connection.socket.remotePort} just connected`));
})

Client side configuration: We can test this code by openning two browser window with the same code. We will the the real time push

let ws = new WebSocket("ws://localhost:3000);
ws.onmessage = message => console.log(message.data);
ws.send("hello");