Kittiphan Techakittiroj (19/09/58 09:28 น. 19/09/58 09:28 น. 19/09/58 09:28 น.) Operating Systems: OS for Client and Server Kittiphan Techakittiroj [email protected]

Kittiphan Techakittiroj (19 . . 2566เม ย )

Operating Systems:OS for Client and Server

Kittiphan Techakittiroj

[email protected]


• Server

– Job of Server

– What do servers need from OS?

• Client

– Job of Client

– What do clients need from OS?

• Examples

Agenda


• Waits for Client-Initiated Requests: polling or

dedicated session

• Executes many requests at the same time: multi-threaded or multi-process, sharing resource

(e.g. network connections, files)

• Service Priority: VIP clients

Server Characteristics


• Initiates and runs background-task activity: sch

eduling (corn in UNIX)

• Reliability: stable, reliable

• Expanable: bigger, fatter, faster

Server Characteristics cont.


• Base Services

– standard for most OS

– built-in

• Extended Services

– add-on modular software

no definite line between these two

change with time

What do servers need from OS?


• Multi-tasking Environment

• Task Management

• Resource Management

• Process Communication

Base ServicesWhat do servers need from OS?


• Standard Requirement

• Two main categories:

– Process: different programs communicate to each

other.

– Thread: same program run many tasks.

• Faster to Create

• Faster to Context Switch

• Easier to access shared information

Concurrent ProgrammingWhat do servers need from OS?: Base Services


• Task Preemption: allow switch between tasks

• Task Priority

• Intertask Protection: protect tasks from interf

ering with each other

Task ManagementWhat do servers need from OS?: Base Services


• File System

– lock mechanism to protect the integrity

– large number of file handle

• Memory management

– swap mechanism

Resource ManagementWhat do servers need from OS?: Base Services


• Interprocess Communications (IPC): allow proce

sses to talk to each other

• Local/Remote Interprocess Communications: transparent between local and remote

Process CommunicationWhat do servers need from OS?: Base Services


• Easier to

Implement

• Reliable

• Portable

• Expandable

Extended ServicesWhat do servers need from OS?


• Ubiquitous Communications: provide variety of

communications protocol

• Network Operating System Extensions: file and

print services over the network

• Internet Services: web servers, ftp servers

• Global Directories and Network Yellow Pages

NetworkingWhat do servers need from OS?: Extended Services


• Binary Large Objects (BLOBs): keeping larg

e object as one single object

• Network Time: allow time synchronization

• Data and Transaction Services: SQL, Transac

tion Processing Monitor

• Authentication and Authorization Services: mainly for security

• System Management

SupportingWhat do servers need from OS?: Extended Services


• Object-Oriented

Services

• Support of

Multi-processor:

– Asymmetric

Multiprocessing

– Symmetric

Multiprocessing

Supporting cont.

What do servers need from OS?: Extended Services


• Non-GUI: no UI or Text-based UI

• simple GUI-Client (Graphical UI)

• OOUI Client (Object-Oriented UI)

no definite line between them

Client Characteristics


• Do NOT Need Multi-tasking: automatic teller ma

chines (ATMs), barcode readers, cellular phone

• Need Multi-tasking: robots, computer numerical c

ontrol (CNCs)

Non-GUI ClientClient Characteristics


What do clients need from OS?GUI OOUI

MultitaskRequest/Reply Yes Yes Yes YesFile Transfer Yes Yes Yes YesPreemptive Multitasking

No Yes Yes/No Yes

Task Priorities No Yes Yes/No YesInterprocess Communications

No Yes Yes/No Yes

Threads No Yes Yes/No YesOS robustness No Yes Yes/No Yes

Non-GUI


• Client-OS: Windows98, MacOS

• Server-OS: WindowsNT Server, AIX

• Both: Linux

OS Examples


• Windows 3.1

• Windows 95 & 98

• WindowsNT Client

• WindowsNT Server

• Advantage

– User Interface

– Support (Hardware, Technical)

Microsoft OSOS Examples


• Designed mainly to be workstation

MacOSOS Examples


• Old system: VAX/VMS

• Usually not support the connectivity

between computer

• Proprietary Systems

Legacy SystemOS Examples


• Specific Vendors: HP (HP/UX), Sun (Solaris), SGI

(IRIX), IBM (AIX)

• Customized for Specific Machine

• Advantage

– Connectivity

– Stability

– Scalability

– Multi-user

– Multi-tasking

Proprietary UNIXOS Examples


• Freeware

• Advantage

– Low Cost

– Multi-platform: 386-based system, SPARC,

PowerPC, Digital Alpha, etc.

– Advantage of normal UNIX

LinuxOS Examples


OS Comparision

http://www.netshooter.com/linux/oscomp.html


OS Comparision cont.


Guide to Choose OS

• Addresses your current needs

• Interoperability

• Support for different hardware platforms

• Maintainability


Reference Books

Client/server survival guide 3rd edition by Robert Orf

ali, Dan Harkey, Jeri Edwards (John Wiley & Son

s: 1999)

Operating Systems Comparision by Phil Hughes (htt

p://www.netshooter.com/linux/oscomp.html: Jan 1

999)

Documents

Kittiphan Techakittiroj (19/09/58 09:28 น. 19/09/58 09:28 น. 19/09/58 09:28 น.) Operating Systems: OS for Client and Server Kittiphan Techakittiroj [email protected]