This is a Georgian toasting song. Mravalzhamier means "many years", i.e. "long life to us". There are different versions of this the song - the one I know is known as "Kartluri Mravalzhamier".
I learnt it in the Bangor Community Choir, and also sang it in the Sing for Water choir in London in September 2011.
Sing for Water choir singing this song in London in 2011
Information about this song (includes recording and score)
Recordings of this song