arch

Design of any system should be considered in two different levels:
▫Architecture design
▫Detailed design

•Hide secrets
▫Representation of data
▫Properties of device (other than required properties)
▫Mechanisms that support policies
•Localize future changes
▫Hide system details likely to change
▫Separate parts that are likely to have a different rate of change

Edsger Dijkstra ja David Parnas olid esimesed teadlased, kes näitasid, kui suur on arhitektuuri mõju lõpptulemusele

Peer-to-peer
• Generalization of client/
server style
• Each subsystem can be a
client and a server
• Two examples from history
Usenet and FidoNet
• Recent application Napster
• Often used in malware,
DDOS attacks and viruses

John von Neumann model
•Neumanni mudelis on riistvara jaotatud 5 gruppi:
▫CPU
▫Input
▫Output
▫Working storage
▫Permanent storage