Application architectures define how network applications are structured and how they allocate tasks between servers and clients.
Here are the key architectures:
- Host-Based Architectures
- Client-Based Architectures
- Client-Server Architectures
- Cloud Computing Architectures
- Peer-to-Peer Architectures
1.) Host-Based Architectures
In a Host-Based Architecture, all processing and data management tasks are performed on a central computer or mainframe (the host), while client devices (terminals) only display the output and provide input to the host.
Characteristics:
- Centralized Processing: All applications, data storage, and computations occur on the central server (host).
- Client Dependency: Clients have minimal computing power and rely heavily on the host for processing.
- Simplicity: Clients only need to interact with the host; they do not perform any complex tasks.
- Limited Scalability: The central host can become a bottleneck as the number of users grows.
- Maintenance and Security: Easier to manage and secure since everything is stored in a central location.
2.) Client-Based Architectures
In a Client-Based Architecture, the client devices handle the bulk of the processing, while the server mainly stores and retrieves data.
- This architecture offloads much of the work from the server to the client, reducing the load on the server.
Characteristics:
- Distributed Processing: The client performs tasks like data processing and calculations, while the server mainly provides data storage and retrieval.
- High Client Load: The client device must be capable of handling complex processing.
- Efficient Network Usage: Since clients do the processing, there is less load on the server and more efficient use of network resources.
- Scalability Issues: As the number of users increases, it can become difficult to maintain performance, as the clients need to handle more tasks.
- Data Consistency: Ensuring data consistency between clients and the server can be more challenging in client-based architectures.
3.) Client-Server Architectures
A Client-Server Architecture is a distributed computing model where the client requests services or resources from a server.
- The server is responsible for managing resources, processing data, and delivering results to clients.
- This model is the most common in networked applications today.
Characteristics:
- Separation of Duties: The client handles user interaction, while the server manages the data, business logic, and complex processing.
- Centralized Data Management: The server stores all data and resources, ensuring centralized control and easier management.
- Scalability: The server can be scaled to accommodate more users by increasing its power or resources (horizontal/vertical scaling).
- Fault Tolerance: Servers can be configured to be fault-tolerant, but the system as a whole depends on the reliability of the server.
- Security Concerns: Since the server holds sensitive data, security becomes a top priority, requiring encryption, access control, and firewalls.
4.) Cloud Computing Architectures
Cloud Computing Architecture refers to a distributed model where applications, data, and services are hosted and managed in the cloud rather than on local servers or individual devices.
- Cloud computing resources are provided over the internet on a pay-as-you-go basis.
Characteristics:
- Scalable and Flexible: Cloud architecture allows organizations to easily scale resources up or down depending on their needs, without the need for physical hardware.
- Cost Efficiency: By utilizing cloud infrastructure, businesses can avoid capital expenses related to owning servers, reducing upfront costs.
- Remote Access: Cloud-based applications can be accessed from anywhere with an internet connection, enabling remote work and collaboration.
- Multi-Tenant: Multiple users or organizations share the same resources, allowing efficient use of resources, but with adequate isolation for each tenant.
- Service Models: Includes Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS), and Software-as-a-Service (SaaS), offering different levels of control and flexibility.
- Security: Cloud security includes encryption, data backup, and multi-factor authentication, though it also raises concerns about data privacy and reliance on third-party providers.
5.) Peer-to-Peer Architectures
Peer-to-Peer (P2P) Architecture is a decentralized model where each device (or node) in the network has equal status and can both serve and request data.
- There is no centralized server; instead, all participants share resources directly with each other.
Characteristics:
- Decentralized Network: Each device acts as both a client and a server, capable of sharing and retrieving data.
- Resource Sharing: P2P networks are commonly used for sharing files and other resources (e.g., BitTorrent, blockchain).
- Scalability: As more peers join the network, the system becomes more powerful since each new peer contributes resources.
- Resilient to Failure: If one peer goes offline, other peers can still continue to share resources, making the network fault-tolerant.
- Security Concerns: Without a central authority, managing security, ensuring data integrity, and protecting against malicious activity (such as malware) becomes more challenging.
- Latency and Performance: P2P networks can suffer from inconsistent performance and latency depending on the number and availability of peers.
