How does a distributed system's architecture support scalability?

A distributed system's architecture supports scalability by allowing for the addition of more nodes to handle increased workload.

In a distributed system, the workload is divided among multiple nodes, each of which operates independently of the others. This decentralised approach allows for greater scalability because as the workload increases, more nodes can be added to the system to handle it. This is in contrast to a centralised system, where the workload is handled by a single node and increasing the system's capacity often involves upgrading the hardware of that single node, which can be costly and complex.

Scalability in a distributed system is achieved through two main strategies: horizontal scaling and vertical scaling. Horizontal scaling involves adding more nodes to the system to increase its capacity. This is often the preferred method of scaling because it allows for a more flexible and cost-effective approach to managing increased workload. For example, if a system is experiencing a temporary spike in demand, additional nodes can be added to handle the increased workload and then removed once the demand subsides.

Vertical scaling, on the other hand, involves increasing the capacity of existing nodes in the system. This can be achieved by adding more powerful hardware to the nodes, such as more powerful processors or more memory. While vertical scaling can also increase the system's capacity, it is often more costly and less flexible than horizontal scaling because it involves upgrading the hardware of existing nodes.

Furthermore, distributed systems are designed to be fault-tolerant, meaning they can continue to operate even if one or more nodes fail. This is achieved through redundancy, where each piece of data is stored on multiple nodes. If one node fails, the system can still access the data from another node. This not only increases the reliability of the system, but also its scalability, as the system can continue to operate effectively even as more nodes are added.

In conclusion, the architecture of a distributed system supports scalability by allowing for the addition of more nodes to handle increased workload, and through strategies such as horizontal and vertical scaling. The system's fault-tolerance also contributes to its scalability, as it allows the system to continue to operate effectively even as more nodes are added.