Why i can't connect to my server?

I can't connect to my minecraft server, ,when i trying to connect, minecraft says "Connection refused: no further information"

Server status in minecraft say "Can't connect to server"

My server status (in linode) says "active" i tried to restart server, i did that many times, one time i turned off server for ~5 minutes and after ~5 minues i turned it on.

Also i created my server yesterday and i was able to join.

I have imported my minecraft world (from singleplayer) to that server, but it was working yesterday.