The working direction of the IT industry
1. Data storage: disks
1) Three architecture storage methods: SAN, NAS, DAS (specially store data in disk arrays) (shared storage architecture)
2) Distributed storage architecture (HDFS)-is a cluster (application)
HDFS-file distributed system defined by Hadoop
2.Linux operating system
3.Data processing:
1) Map-reduces data processing cluster: It is to modify massive data into key-value relationships (key-value) in a certain way
HDFS + map-reduces = Hadoop cluster (a high-performance running on Linux Cluster)
Algorithm: 2) Through mathematics (statistics) + Python = algorithm
3) Data visualization
4. Cloud computing-big data
1) Operation and maintenance: Linux operating system (Windows–desktop engineer)
(Linux operation and maintenance: web architecture, build your own personal website)
(1)HDFS distributed storage
(2)map-reduces
(3)Hive (SQL)
(4)spark (scala language)
2) Development–computer language
BASIC early mechanical language
C language C++: system development, driver development, embedded development (writing Board)
(Driver: need to convert the instruction set between each manufacturer’s equipment, so that the manufacturer’s equipment can communicate with each other)
Front end: JS php css html
Tool: script language (shell\perl\python)
Introduction to the operating system
1. What does the operating system do?
Platform —- Link from above to below
Top: Application
Bottom: Hardware equipment (resource)
The three major components of hardware equipment platform: CPU, memory, I/O equipment
( Computer controller memory input device output device)
CPU:All calculations
Memory: Provide data to the CPU (cpu can only read data to the memory), restart the system, the data in the memory will be lost:< br>CPU reads the specified (required data) in the memory. This process is called addressing; (physical address, logical address)
IO device: network card (adapter): Ethernet
disk (IDE, SAS, SSD)
Mechanical Disk Solid State Disk
Knowledge extension:
osi seven-layer model———— ——— Four-layer model of TCP/IP
Application layer: QQ ———————– | Presentation layer: Command conversion —————-| Application layer Session layer: Session establishment session ——| Transport layer: Differentiating applications by port—– Transport layer network layer: IP address ——————– network layer data link layer: MAC address (physical address) ——–|Physical Layer: Specific physical device (hardware device)——|Host to host layer Note [The lower layer provides services for the upper layer] Operating system: itself is a software program, but it does not directly provide applications to customers. It is to provide hardware resources for other applications; the operating system is divided into: user space, kernel space