## Centralised vs. Distributed Control Systems [block_0] #### Centralised Control Systems [block_1] **Centralised control systems** rely on a **single** **central** **computer** to manage all **processing** and **decision-making**. A control system that relies on a **single** **central** **computer** to manage all **processing** and **decision-making** This architecture offers several advantages: 1. **Simplified Management**: All data and processes are handled in one location, making it easier to monitor and control. 2. **Cost-Effective**: Client devices require minimal hardware since the central system performs all computations. 3. **Enhanced Security**: Data is stored centrally, reducing the risk of unauthorised access across multiple locations. 4. **Efficient Backup**: With all resources in one place, backing up data is straightforward and less resource-intensive. [{"_key":"block_9","_type":"block","asset":null,"children":[{"_key":"b617aa046053","_type":"span","markDefs":[],"marks":[],"text":"Centralised systems are often used in environments where "},{"_key":"cb4d7a077d94","_type":"span","marks":["strong"],"text":"reliability "},{"_key":"ccf13cdc5e74","_type":"span","marks":[],"text":"and "},{"_key":"51f65e6387aa","_type":"span","marks":["strong"],"text":"control "},{"_key":"7b0aad3a6b7e","_type":"span","marks":[],"text":"are "},{"_key":"970043b1813f","_type":"span","marks":["strong"],"text":"paramount"},{"_key":"d64dce0b9875","_type":"span","marks":[],"text":", such as "},{"_key":"fc15b5ce5980","_type":"span","marks":["strong"],"text":"banking "},{"_key":"05dc3e8fb7ac","_type":"span","marks":[],"text":"systems or "},{"_key":"a9eb9be6c0d7","_type":"span","marks":["strong"],"text":"large-scale enterprise networks"},{"_key":"dabf8d2595a3","_type":"span","marks":[],"text":"."}],"markDefs":[],"style":"normal"}] In contrast, the disadvantages are: 1. **Single Point of Failure**: If the central system or its connection fails, the entire network can become inoperative. 2. **Scalability Challenges**: Expanding the system requires a significant investment in the central infrastructure. 3. **Network Dependency**: Client devices must maintain a stable connection to the central system, which can be a bottleneck. [{"_key":"block_16","_type":"block","asset":null,"children":[{"_key":"AJhyQgUp1y5tieuNl4JwW8","_type":"span","markDefs":[],"marks":[],"text":"A common misconception is that centralised systems are always more secure."}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"},{"_key":"da237805c81e","_type":"block","asset":null,"children":[{"_key":"9882ab2e5b2f","_type":"span","markDefs":[],"marks":[],"text":"While data is stored in one location, a breach of the central system can compromise the entire network."}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"}] #### Distributed Control Systems [block_17] A control system that spreads **processing** and **decision-making** across **multiple** **independent** **nodes** Each node can operate autonomously, offering several advantages: 1. **Resilience**: If one node fails, others can continue to function, ensuring system stability. 2. **Scalability**: New nodes can be added without disrupting the existing system. 3. **Reduced Latency**: Processing is done locally, minimising delays caused by network communication. [{"_key":"block_24","_type":"block","asset":null,"children":[{"_key":"cec8904cc5a0","_type":"span","markDefs":[],"marks":[],"text":"Distributed systems are ideal for applications such as "},{"_key":"d2613689b8ed","_type":"span","marks":["strong"],"text":"smart grids "},{"_key":"7585c2419e20","_type":"span","marks":[],"text":"or "},{"_key":"a8464ac97739","_type":"span","marks":["strong"],"text":"autonomous vehicles"},{"_key":"b843f397d1c5","_type":"span","marks":[],"text":", where "},{"_key":"272627051bea","_type":"span","marks":["strong"],"text":"real-time decision-making "},{"_key":"159c883177ee","_type":"span","marks":[],"text":"is "},{"_key":"03bd5841c59c","_type":"span","marks":["strong"],"text":"crucial"},{"_key":"8d2869352d8b","_type":"span","marks":[],"text":"."}],"markDefs":[],"style":"normal"}] And disadvantages such as: 1. **Higher Costs**: Each node requires its own hardware and software, resulting in increased initial expenses. 2. **Complex Management**: Coordinating multiple nodes can be challenging, particularly in terms of maintaining data consistency and ensuring security. 3. **Backup Complexity**: Distributed data requires more resources for synchronisation and backup. [{"_key":"block_31","_type":"block","asset":null,"children":[{"_key":"2v6FBoxifQrTfkudSc4DS2","_type":"span","markDefs":[],"marks":[],"text":"It's a common mistake to assume that distributed systems are always more reliable. "}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"},{"_key":"a67c6833c838","_type":"block","asset":null,"children":[{"_key":"598d7141d2bc","_type":"span","markDefs":[],"marks":[],"text":"While they offer redundancy, poor coordination between nodes can lead to data inconsistencies or system failures."}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"}] #### TL,DR: Comparing Centralised and Distributed Systems [block_32] | Aspect | Centralised Systems | Distributed Systems | | --- | --- | --- | | Architecture | Single central computer | Multiple independent nodes | | Scalability | Limited by central system capacity | Easily expandable by adding nodes | | Resilience | Single point of failure | Redundant, with nodes operating independently | | Cost | Lower initial cost for clients | Higher initial cost due to distributed hardware | | Security | Easier to secure centrally stored data | More challenging to secure multiple nodes | | Latency | Higher, due to network dependency | Lower, with local processing | [{"_key":"block_36","_type":"block","asset":null,"children":[{"_key":"88f3c4142088","_type":"span","markDefs":[],"marks":[],"text":"Imagine a centralised system as a "},{"_key":"502f5acdb8f6","_type":"span","marks":["strong"],"text":"single traffic control tower "},{"_key":"d98e37890277","_type":"span","marks":[],"text":"managing an entire city's traffic lights."}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"},{"_key":"4a3e1f514754","_type":"block","asset":null,"children":[{"_key":"57a690ce1a20","_type":"span","marks":[],"text":"If the tower fails, chaos ensues. "}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"},{"_key":"795fef9996ad","_type":"block","asset":null,"children":[{"_key":"f3818563d5d7","_type":"span","marks":[],"text":"In contrast, a distributed system is like "},{"_key":"29553ff23df0","_type":"span","marks":["strong"],"text":"each intersection "},{"_key":"1f4632387901","_type":"span","marks":[],"text":"having its own "},{"_key":"b0d465a99b59","_type":"span","markDefs":[],"marks":["strong"],"text":"controller"},{"_key":"8b8909403a0d","_type":"span","markDefs":[],"marks":[],"text":", ensuring traffic flows smoothly even if one controller malfunctions."}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"}] [{"_key":"ac4f5d3d914a","_type":"block","asset":null,"children":[{"_key":"d3239e534f99","_type":"span","markDefs":[],"marks":[],"text":"Imagine, in the case of smart grids, a single control centre manages power distribution, optimising efficiency but risking widespread outages if the centre fails. "}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"},{"_key":"d975f139806c","_type":"block","asset":null,"children":[{"_key":"352a56d78e94","_type":"span","markDefs":[],"marks":[],"text":"In contrast, in the case of a distributed system, local nodes adjust power distribution based on real-time data, enhancing resilience and reducing downtime."}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"}] #### Ethical and Practical Considerations [block_49] 1. **Data Privacy**: Centralised systems may offer better data protection, but a breach can have widespread consequences. Distributed systems require robust encryption and access controls across all nodes. 2. **Resource Allocation**: Distributed systems can be more energy-efficient by processing data locally, reducing the need for constant communication with a central server. 3. **Scalability vs. Cost**: Organisations must balance the scalability of distributed systems with the higher initial costs of hardware and software. [{"_key":"c0c58caa4ca7","_type":"block","asset":null,"children":[{"_key":"c967a882b59e","_type":"span","markDefs":[],"marks":[],"text":"Understanding the differences between centralised and distributed control systems is crucial for designing efficient, resilient, and scalable solutions. As you explore these architectures, consider the following:"}],"markDefs":[],"style":"normal"},{"_key":"48e50fa5d4d6","_type":"block","asset":null,"children":[{"_key":"a01c12dd47af","_type":"span","markDefs":[],"marks":["strong"],"text":"Context Matters"},{"_key":"e56876c5eca3","_type":"span","markDefs":[],"marks":[],"text":": The choice between centralised and distributed systems depends on the specific requirements of the application, such as scalability, resilience, and cost."}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"},{"_key":"3c02a6b3aeb9","_type":"block","asset":null,"children":[{"_key":"e8d9d761e18e","_type":"span","markDefs":[],"marks":["strong"],"text":"Balance Trade-Offs"},{"_key":"90fc9ea3c1ac","_type":"span","markDefs":[],"marks":[],"text":": Each architecture has its strengths and weaknesses. Effective system design involves striking a balance between these trade-offs to meet the needs of both users and the environment."}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"},{"_key":"4a430c81c276","_type":"block","asset":null,"children":[{"_key":"5eafc2bec251","_type":"span","markDefs":[],"marks":["strong"],"text":"Think Critically"},{"_key":"6a059a6f32ed","_type":"span","markDefs":[],"marks":[],"text":": When evaluating control systems, consider not only their technical capabilities but also their ethical and social implications."}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"}] [{"_key":"block_48","_type":"block","asset":null,"children":[{"_key":"64ded64ccd93","_type":"span","markDefs":[],"marks":[],"text":"What are the key differences between centralised and distributed control systems? "}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"},{"_key":"67a19f8f8e90","_type":"block","asset":null,"children":[{"_key":"d3defa1b5636","_type":"span","markDefs":[],"marks":[],"text":"How do distributed systems handle failures compared to centralised systems? "}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"},{"_key":"ecf51daa0f4c","_type":"block","asset":null,"children":[{"_key":"079d7a465813","_type":"span","markDefs":[],"marks":[],"text":"Can you think of a scenario where a centralised system might be more appropriate than a distributed one?"}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"}] [{"_key":"block_55","_type":"block","asset":null,"children":[{"_key":"5955196f3a70","_type":"span","markDefs":[],"marks":[],"text":"How do centralised and distributed systems reflect different approaches to problem-solving in computer science?"}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"},{"_key":"fe143ad95003","_type":"block","asset":null,"children":[{"_key":"e06a7784b314","_type":"span","markDefs":[],"marks":[],"text":"What ethical considerations arise when choosing one architecture over the other?"}],"level":1,"listItem":"bullet","markDefs":[],"style":"normal"}]