UNIT 6 - – Embedded System
Embedded System
A computer system that performs a specific function for controlling a machine or other systems requiring control, and an electronic system in the device.
it is a system with a built-in microprocessor and a program that drives the microprocessor to perform a specific function
Embedded hardware
consists of a microprocessor/microcontroller, equivalent to a CPU, memory, input/output device, network device, sensor, driver, etc
Embedded software
consists of an operating system (OS) that directly controls hardware and manages the software, system software, and application software.
EMBEDDED SYSTEM CONFIGURATION
Low cost
Low performance
Resource constraints
Stability
Resilience
Characteristics of embedded system
Embedded system development process
Early microprocessor units (MPUs)
____were made in a single chip, in which registers data processing, arithmetic logic unit (ALU) for mathematical operation, and flags for storing result values were integrated into a chip.
Embedded software
___ refers to software installed in embedded systems
Characteristics of embedded software
Embedded OS structure
Technologies applied to embedded
Real-time OS (RTOS):
Mainly focuses on controlling application programs or hardware affected by a limited amount of time. The leading operating systems include VxWorks, VRTX, QNX, and pSOS
Non real-time OS:
Mainly focuses on development convenience, scalability, and diverse operating environments. The leading operating systems include Linux series, embedded Window XP. and Windows CE
Linux
___is installed in about 65% of all embedded devices and is still growing very fast, at an annual average of 17%
UNIT 7: Information System Implementation
Information system
uses information technology (IT) to perform business procedures, such as providing necessary information, or business processing required by enterprise
creates a system that enables IT personnel to provide IT services by using IT components, such as hardware and software, to perform organizational business procedures.
web system architecture
client-server system architecture
types of structures for an information system:
WEB SYSTEM ARCHITECTURE
server
A ___is the most fundamental component required when implementing an information system.
A__ is a hardware platform that runs server application programs and is classified in various ways, according to performance and type as follows.
Storage
___is classified into enterprise or mid-range storage, according to processing capacity, It provides large storage space, high performance, and high availability, compared to general disk arrays.
OS
An__ is defined as system software that operates and manages an application platform and that provides an interface between an application program and the platform.
webserver
A __ provides media content, such as HTML and text, images, and video, to web clients, like web browsers. It provides data through the HTTP protocol to enable a web browser to present information. Leading webserver products include Apache, Nginx, and IS (see [Figure 78}).
Web application server (WAS)
A ___ is a middleware that enables the stable transaction processing of web client requests and helps develop the distributed systems.
Transaction processing (TP) monitor
A___ is transaction management middleware that supports the distributed transaction processing and monitors transactions, which are the minimum processing units between active sessions and systems in various protocols, in order to maintain them consistently
DB server (Database management system, DBMS):
A ___ server provides the database type, database management technology, and query language for the access to and modification of structural data.
Concept of size calculation
System sizing is to estimate or calculate a system's size using a mathematical methodology, based on actual work and applications.
. Concept of size calculation
Sizing is a matter of prediction, and the calculation method significantly affects the accuracy of the calculation. Hardware size calculation methods are generally classified into the mathematical calculation,
. Size calculation targets
the target for sizing includes not only hardware, but also software or network. As shown in [Figure 83], the size calculation target in the capacity calculation guidelines is hardware, which is defined as servers, not PCs or other peripherals.
3 tier Architetcture
validate basic data and task analysis
reference model
hyper converged infrastructure (HCI)
__ is a concept that overcomes the limitations of Cl by eliminating the expensive external storage
UNIT 8: Fault Response Technology
High Availability (HA)
___refers to an uninterrupted service. However, it is not easy to make a system, that consists of numerous parts and software, 100% availabl
Availability Calculation Formula
Hot standby (Active-standby)
Mutual takeover (Active-active)
Concurrent access
HA configuration type
Hot standby (Active-standby)
the simplest structure of HA clustering implementation. It consists of an active server and a standby server that are normally in a standby state. The standby server is powered on, and the operating system is running.
Mutual takeover (Active-active)
is the case of two or more systems operating with separate servers. When a server fails, its services are switched to the designated server (takeover) to continue the services
Concurrent access
a structure in which multiple systems process tasks in parallel in order to provide availability. Al servers operate in an active state. Even if a server fails, the service continuity can be guaranteed without a fail-over.
fault-tolerant system
A ___can continuously perform the functions specified in the design, even if a system part fails.
it cannot use certain functions when a component fails
When components continue to fail, the unavailable functions gradually increase, and the system shuts down when a critical failure occurs.
Disaster Recovery System
an overall plan and system to minimize the impact of a disaster on a business, by locating al or part of the information system infrastructure in a location different from the disaster point, then quickly recovering from a disaster when it occurs.
Recovery Time Objective (RTO)
Recovery Point Objective (RPO).
The most important factors to consider when implementing a Disaster Recovery (DR) system are __ and _