Chapter 7: System Architecture Flashcards
Client-based systems
execute all core functions on the user’s device and don’t require network connectivity
Server-based systems
require a client make requests from a server across a network connection
Transactions
sequences of actions required to properly change the state of a database
Properties of Database transactions
atomic, consistent, isolated, durable (ACID)
Aggregation
combining info from separate sources; security problem when it allows unauthorized individuals to piece together sensitive info
Inference
deducing a whole set of info from a subset of its aggregated components; security problem when it allows unauthorized individuals to infer sensitive info
HPC
High-performance computing; aggregation of computing power which exceed capabilities of general-purpose computers for the specific purpose of solving large problems
ICS
Industrial control systems; IT specifically designed to control physical devices in industrial processes
Embedded system
cyber-physical system; computers and physical devices collaborate via the exchange of inputs and outputs to accomplish a task or objective
Two main types of ICS
DCS and SCADA
DCS
distributed control systems; use PLC; control devices within fairly close proximity
SCADA
supervisory control and data acquisition system; uses RTUs or PLCs; control large-scale physical processes involving nodes separated by significant distances
Difference between DCS and SCADA
DCS controls local processes; SCADA used to control things remotely
ICS connectivity
should always be logically or physically isolated from public networks
Virtualized system
exist in software-simulated environments
VM
virtual machine; computing hardware has been virtualized for the operating systems running in them
Containers
systems in which the operating systems have been virtualized for the applications running in them; very common for containers and microservices to be used together; houst microservices; run in sandboxes
Microservices
software architectures; features are divided into multiple separate components which work together in a distributed manner across a network
serverless architecture
services offered to end user can be performed without a requirement to set up any dedicated server infrastructure
Cloud computing
use of shared, remote computing devices for the purpose of providing improved efficiencies, performance, reliability, scalability, and security
SaaS
Software as a Service; cloud computing model which provides users access to specific application that executes in the service provider’s environment
PaaS
Platform as a Service; cloud computing model which provides users access to a computing platform but not to the operating system or to the virtual machine on which it runs
IaaS
Infrastructure as a Service; cloud computing model which provides users unfettered access to a cloud device, like an instance of a server, which includes both the operating system and virtual machine on which it runs
Embedded system
self-contained, ruggedized, computer system with its own processor, memory, and input/output devices designed for a very specific purpose
IoT
Internet of Things; global network of connected embedded systems
distributed system
system in which multiple computing nodes, interconnected by a network, exchange info for the accomplishment of collective tasks
Edge computing
a distributed system in which some computational and data storage assets are deployed close to where they are needed in order to reduce latency and network traffic
PLC
programmable logic controller
RTU
remote terminal unit
Hypervisors
used to virtualize the hardware on which virtual machines run; provide visibility and logging as a secondary function
Virtualizing the operating system
Containers
Issues when securing embedded systems
use of proprietary code, devices that “phone home”, ability to update and patch them securely
Microcontrollers
specialized devices with CPU, memory, and peripheral control interfaces; used to build embedded systems
Three layers of edge computing
End devices, edge devices, and cloud infrastructure
