1

2011

.

2

:

. 2310 013592

Email: kdiamant@it.teithe.gr

, , :

http://www.it.teithe.gr/~kdiamant/

:

W. Stallings, , 6 ., , 2009

G. Coulouris, J. Dollimore, T. Kindberg, Distributed Systems Concept and Design, 4th ed. Addison Wesley, 2005.

10%

.

3

(middleware)

(Remote Procedure Calls - RPC)

CORBA

JAVA Remote Method Invocation (RMI)

Web

Clusters ( )

: google apps

.

4

: (hardware) (software)

(resources)

,

,

,

,

5

.

.

6

(loosely coupled nodes)

= , , ,

= ,

( )

(. Intel x86, Linux, MAC, ) . . Ethernet, TCP/IP.

, . (. /, , , )

:

: ()

:

: -

.

7

.

8

(Heterogeneity)

(Openness)

(Security)

(Scalability)

(Failure handling)

(Concurrency)

(Transparency)

internet:

intranet

: (internet)

.

9

(backbone)

intranet

intranet

= (server)

= (clients)

=

intranet

intranet

(internet)

.

10

: . - Internet Protocol (IP).

, , , (World Wide Web), email, (ftp), , .

Intranets : / (. )

(intranet)

.

11

, , ,

Web server

Email server

File server

Print server

Email server

File server

Print server

Router

File server

Internet

.

12

(Internet Service Providers ISP) : . (intranet) ISP.

(backbone) : (. ). . internet exchange points.

.

13

(client): / , ( )

(server): , ( )

(Application Programming interface API):

(Middleware): .

.

14

(Networked Operating System). (client server): - (clients) - (servers). . - .

(Distributed Operating System). .

.

15

UNIX, Windows, MacOS

. :

() ( )

. . .

(1)

.

16

, (hardware) .

(middleware)

(hardware)

: (. Email).

: API .

:

(2)

.

17

Interface

1 (, , , )

1 ( )

(, , , )

( )

.........

1

Application Program Interface (API)

(middleware)

.

18

Middleware: . (objects) (processes) .

Middleware:

Remote Procedure Calls (RPC)

CORBA (Common Object Request Broker Architecture) OMG (Open Management Group)

Java RMI (remote method invocation)

web

Distributed Component Object Model (DCOM) Microsoft

.

19

Middleware

RMI, RPC, events

/

-

.

20

:

( TCP/IP)

-

.

21

( GUI)

: Web

.

22

http

http

:

: Mozilla Firefox (Web browser)

Firefox

http://195.251.123.246/

Firefox html, .

:

: Apache (http server)

http

() html

= html

html

: Web

.

23

(, Windows, Linux, Mac OS, )

(, Windows Server, UNIX, Mac OS X Server, )

hyper-text (hyper-text transfer protocol http) : . / .

: Domain Name (DNS)

.

24

DNS

DNS

:

: nslookup (DOS)

nslookup

nslookup www.it.teithe.gr

nslookup IP address .

:

: BIND (DN Server Unix)

IP address = 195.251.123.246

= IP address

IP address

:

.

25

. (queries) () () . .

DBMS

( + )

. .

(GUI)

( + )

/

.

26

(client-based)

(GUI)

DBMS

/

.

27

(server-based)

, graphical user interface (GUI)

(GUI)

DBMS

:

.

28

E-mail client

/ .

:

: Mozilla Thunderbird (email client)

.

:

: Microsoft Exchange Server

: SMTP POP3/IMAP

=

SMTP

POP/IMAP

: (1)

.

29

Web mail

http

:

: Google Chrome (web browser)

( http) ,

http://webmail.teithe.gr

Chrome

(Google):

: Horde (open source webmail server)

html

. html

html

http

: (2)

.

30

Google search

search

:

: Internet Explorer (web browser)

( http) search

www.google.com

IE

(Google):

: google ( )

search

html

= html

html

search