CENTRALISED SYSTEMS
Academic Year 2024/2025 - Teacher: FABRIZIO MESSINAExpected Learning Outcomes
The Central Systems course presents the fundamentals of designing processing systems, through the treatment of three main processing models: i) Central systems, or mainframes, ii) systems for distributed processing `` on premise '' iii) Cloud systems and processing.
General objectives of teaching in terms of expected learning outcomes:
- Knowledge and understanding: the primary objective of the course is identified in the acquisition by the students of the basic concepts of the design of a processing system with particular i) reliability, ii) scalability and iii ) sizing. The basic concepts of resource virtualization, the business models of Cloud Computing, the history and architecture of the so-called mainframes will be addressed.
- Applying knowledge and understanding: we intend to provide the tools to achieve the following practical and professional skills: ability to understand and analyze the main requirements for a specific processing system; ability to select model and technologies for a specific processing system; ability to estimate the size of a processing system; implement appropriate design choices to obtain the reliability and scalability of the processing system.
- Making judgments: through the examination of some examples and case studies, the learner will be able, even in a cooperative form, to design a solution that can be considered sub-optimal with respect to the problem to be solved.
- Communication skills: the student will acquire some communication skills aimed at describing the key components of a processing system.
- Learning skills: the course aims to provide the student with some theoretical and practical methodologies to be used in professional contexts. In particular, the ability to understand technological evolution on the one hand, as well as changes in business models related to the use of processing systems.
Course Structure
Required Prerequisites
Attendance of Lessons
Detailed Course Content
Introductory material.
Course objectives
The course plan
Method of examination
Computing models.
Centralized
Client server
Distributed
Cloud computing.
Business Continuity and Scalability
FIRST PART
Three-level architecture
SECOND PART
Business Continuity and Scalability.
High reliability (High Availability)
Clusters
Load balancers and load balancing.
Balancing policies
Horizontal and vertical scalability
Disk redundancy (RAID).
Points of failure (single point of failure).
Backup and recovery
Disaster Recovery
Estimation of system sizing and topology
PART ONE: THE NEED FOR SIZING
Estimation of system sizing and topology
The estimate for the project budget
The purchase of the infrastructure.
Development cycle: required environments.
SECOND PART: SIZING METHODOLOGY.
Requirements of software scalability.
Estimation of CPUs and RAM.
Contingency and think time.
Processor throughput.
The sizing of the database.
The sizing of the file system.
Volume growth and capacity plan.
The stress test.
THIRD PART: TOPOLOGY
Defining the topology
Factors affecting the topology
A heuristic approach
Virtualization
PART ONE: UNDERSTANDING VIRTUALIZATION
The concept of virtualization
The importance of virtualization
Trends and cloud computing
SECOND PART: VIRTUALIZATION OF THE SYSTEM
Hypervisor
Virtual machine (VM)
Resource management in virtual machine. CPU, RAM, storage.
Copy and cloning of virtual machines.
THIRD PART: USING VIRTUALIZATION
Virtualized system availability
IT applications in a virtualized environment
Virtualization software vendors
Containers
Cloud architecture
PART ONE: CHARACTERISTICS OF CLOUD COMPUTING
Cloud service models
Deployment models: advantages and disadvantages
Cloud infrastructure
Cloud networking
Interaction between cloud and on premise environments
Cloud storage
SECOND PART: CLOUD COMPUTING FOR COMPANIES
Cost considerations
IT department
Balance sheet and cash flow
Service Level Agreement (SLA)
Elasticity and scalability
Autoscaling
Cooldown time
Business continuity and DR in cloud
Environments and development cycles of software systems
Automatic updates, P2T and T2T
Central systems
Introduction and History of Central Systems
Introduction to Computer Architecture (z / Architecture)
Course Planning
| Subjects | Text References | |
|---|---|---|
| 1 | Computing models, centralized distributed and Cloud. | Material provided by the teacher. |
| 2 | Processing models. | Material provided by the teacher. |
| 3 | Business continuity and scalability. | Material provided by the teacher. |
| 4 | Estimating the sizing of the system. | Material provided by the teacher. |
| 5 | Virtualization. | Material provided by the teacher. |
| 6 | Cloud architecture. | Material provided by the teacher. |
Learning Assessment
Learning Assessment Procedures
The exam will consist in a test witn multiple predefined answers.
Students can carry out groups project (essay o brief researches) in place of the final exam.
Examples of frequently asked questions and / or exercises
Three layer architecture.
Scalability and vilnerability.
Recovery techniques.
Resource requirement estimation to size the system.
Scalability requirements.
What is the virtualization.
What is an hypervisor.
Container vs virtual machines.
Cloud computing models.
Service Level Agreement
Autoscaling and elasticity
Technique to evaluate / estimate costs.