Client–server model

Client–server model

The client–server model is a way that distributed applications are set up, where tasks are divided between servers (providers of a resource or service) and clients (requesters of that service). It's a core concept in computer networking and forms the basis of much of the internet.

Clients typically start communication with servers, which wait for requests. Servers provide resources or services to many clients, often at the same time.

Overview and Purpose

This model distributes tasks and data storage across multiple networked systems.

Its main goals are:

• Centralized Resources: Resources like databases and files are managed on servers, making them accessible to many clients and easier to update.
• Task Division: Clients handle user interfaces, while servers manage data storage, processing, and services.
• Scalability: Servers can be upgraded independently to handle more clients or heavier workloads.
• Simpler Clients: Clients can be basic devices that rely on the server for most tasks and data.

How it Works

The client–server interaction follows a request–response pattern: 1. The client connects to the server over a network. 2. The client sends a request for a service or resource using a specific protocol. 3. The server processes the request (e.g., accesses databases, runs calculations, retrieves files). 4. The server sends a response back to the client with the requested data or a status. 5. The client receives the response and shows the information to the user.

Servers are usually powerful computers handling many requests reliably. Clients can be anything from desktops to smartphones. Communication uses various network protocols like HTTP for web browsing or SFTP for file transfer.

Examples

The client-server model is used in many applications:

• World Wide Web: Web browsers (clients) request pages from web servers.
• Email: Email clients send/receive emails from mail servers.
• File Transfer: FTP/SFTP clients transfer files to/from file servers.
• Online Gaming: Game clients connect to game servers.
• Database Access: Database clients query data on database servers.
• DNS: DNS clients request IP addresses from DNS servers.

Advantages

• Centralized Control: Easier to manage, update, and secure data on a central server.
• Resource Sharing: Clients share resources like printers or storage.
• Data Consistency: Central storage helps ensure data consistency and backups.
• Scalability: Server capacity can be increased for more clients.
• Reliability: A client failure usually doesn't affect the server or other clients.

Disadvantages

• Server Dependence: If the server fails or is overloaded, services become unavailable.
• Network Dependence: Requires a stable network connection.
• Server Bottlenecks: A single server can be overwhelmed by too many requests.
• Initial Server Cost: Setting up server infrastructure can be expensive.

The Client–Server Model at Pulsed Media

Pulsed Media's services, including seedboxes, Virtual Private Servers (VPS), and Dedicated Servers, are built on the client–server model.

• The Servers: Pulsed Media's physical servers in data centers act as the servers.

   * Dedicated servers are allocated entirely to one user.
   * VPS involves powerful physical servers hosting multiple virtual machines, each a VPS for a user.
   * Seedboxes are hosted on physical servers, often shared, where a user's resources are their portion of the server. These servers run the operating system, applications (like torrent clients, web servers), and store user data.

• The Clients: Your local computer, laptop, smartphone, or other device running client applications.

   * Your web browser is the client when accessing web-based control panels or application GUIs (like rTorrent's web UI).
   * SFTP/FTP software on your machine acts as the client for file transfers.
   * An SSH client on your device connects to the SSH server for command-line access.

While a seedbox itself acts as a client for torrent networks, from your perspective, your local machine is the client accessing the remote seedbox server.

In short, Pulsed Media provides the server infrastructure. Users then use client applications on their devices to connect to these servers, send requests (e.g., download/upload files, run commands, access web interfaces), and receive responses, using Pulsed Media's services.

See also

• Server (computing)
• Download
• Upload