This document discusses hierarchical software architectures, including master-slave and main-subroutine architectures. It describes how hierarchical architectures organize systems into layers with specific responsibilities that interact with adjacent layers. Master-slave architecture involves a central master that coordinates subordinate slaves to perform tasks and report results back. Main-subroutine architecture similarly breaks programs into a main program and reusable subroutines.

1. Hierarchical Software
Architecture
• Master-Slave
• Main-subroutine
By: Abdullah
(21014198-097)

2. Hierarchical Software Architecture
• Hierarchical software architecture organizes a system into hierarchical layers or
sub-systems.
• Each layer has a specific responsibility and interacts primarily with its immediate
neighboring layers. This model provides a clear structure and promotes
modularity and scalability.
• The top layer represents the overall system, and as you move down the
hierarchy, the components become more specialized and granular.
• Hierarchical Architecture are commonly used in large scale systems to manage
complexity and promote separation of concerns.

3. Master-Slave Architecture Style
• The Master has a number of independent jobs that need to be executed. It sends
separate jobs to all its Slaves.
• The Slave processes the job and send feedback result to Master.
• The Master integrates the results in its database and feeds the Client more data.
Master
Slave Slave Slave

4. Master-Slave Architecture
• The Master-Slave architecture model involves a central control component called
the Master and multiple subordinate components are called Slaves.
• The master coordinates and delegates tasks to the slaves, which perform specific
functions and computations.
• The slaves report back to the master with their results.
• This module is useful in dividing the workload among multiple slaves to achieve
faster and more efficient processing.

5. Master-slave Architecture in database
replication.
• The master-slave Architecture in database replication offers several benefits.
• Firstly, it provides fault tolerance, as even if the master database fails, one of the
slave databases can be promoted to become the new master.
• Secondly, it allows for load balancing, as read requests can be distributed among
the slave databases, reducing the load on the master.
• Lastly, it improves data availability, as client applications can be read from any of
the available slave databases, even if the master is temporarily unavailable.

6. Main/Subroutine Architecture style
• The main/subroutine Architecture also known as the main program and
subroutine Architecture, is a traditional software design pattern used in
procedural programming languages.
• However, with the rise of object-oriented programming and other modern
architectural patterns, the main /subordinate style is less commonly used in
contemporary software development.
• Purpose
• Subordinates reuses and individual subordinates developed independently.
• Using this style, software system is decomposed into subroutines hierarchically
refined according to the desired functionality.

7. Main/Subroutine Architecture Style
• Data is passed as parameters to subroutines from callers.
• Pass by reference
• Pass by value
Caller
Subroutine
Subroutine
Subroutine
Subroutine

8. Thank you