Central Systems

Academic Year 2023/2024 - Teacher: FABRIZIO MESSINA

Expected 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:

  1. 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.
  2. 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.
  3. 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.
  4. Communication skills: the student will acquire some communication skills aimed at describing the key components of a processing system.
  5. 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

Frontal lessons

Required Prerequisites

Basic knowledge of computer architectures, computer networks and operating systems.

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

 SubjectsText References
1Computing models, centralized distributed and Cloud. Material provided by the teacher.
2Processing models. Material provided by the teacher.
3Business continuity  and scalability. Material provided by the teacher.
4Estimating the sizing of the system. Material provided by the teacher.
5Virtualization. Material provided by the teacher.
6Cloud 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.