self doubt

Question

when we say http is stateless and ftp is statefull. what does it realy mean. what does statefull and stateles means.

Comments

Hope you've watched 'Ghajini' movie.There the 'sanjay singhania' before being hit by iron rod is kind of stateful protocol and the 'sanjay singhania' after being hit by iron rod is kind of stateless protocol.

now let me explain in more detain ,how. The sanjay singhania after being hit got memory loss and he remembers nothing about past. whenever you talk with him , you have to tell him each and every thing . like your identity , your reason of talking and other details and after you disconnect with him , he will forget you completely so when you want to talk him again , you have to again start from beginning , like your identity. so i mean to say , he maintain no state in his mind about you. every time you're a new person to him.This is HTTP protocol , every request is treated by server as  a new request. he remembers nothing about you after you got disconnect. the basic reason is to lesser the burden. there would be a lots of request and saving some metadata about each request would kill the performance of http server drastically.

now come to sajay singhania before being hit by rod. He is smart person , who remembers everything about , what  you have talked with him last day. and when you wish to talk with him again , it would just welcome you because now you're a known person to him and you can direct talk point to point rather starting everything from beginning because he remembers nothing of last time.

FTP is stateful protocol , ftp servers stores metadata about sources and with the help of this data , when you send request next time , server can acknowledge easily as you're in kind of active connection.

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thank u u explained very well.

Answer 1

HTTP is a stateless protocol, in other word the server will forget everything related to client/browser state. 

the FTP protocol is stateful: the client establishes a Control Connection for the duration of an FTP session that typically spans multiple data transfers.

Answer 2

Stateful means the computer or program keeps track of the state of interaction, usually by setting values in a storage field designated for that purpose.

Stateless means there is no record of previous interactions and each interaction request has to be handled based entirely on information that comes with it.

http is stateless because it doesn't maintain any information regarding user, where as, ftp is stateful,