Definition
Centralised Architecture ( Distributed System)
A centralised architecture concentrates service provision or coordination at a central point on which participating clients depend. Clients submit requests to a server, which performs the required operations and returns results.
In a synchronous request–reply interaction, the client waits for the result before continuing the dependent computation. The server receives the request, provides the service, and sends a reply.
Solid segments show computation in this interaction. The client waits during request transmission, server processing and reply transmission; server-side queueing is omitted from the diagram.
Request–Reply Cost
Measured from sending the request to receiving its reply, the client’s waiting time comprises
Asynchronous requests can allow independent work during this interval through latency hiding. They do not remove the server’s processing or communication costs.
Central Dependency
A centralised service can become a capacity bottleneck or a single point of failure unless suitable capacity and recovery mechanisms are provided.
Client and server are interaction roles: using them does not by itself imply a centralised architecture. Requests may instead be handled by several independently responsible servers.