Recording number of years controlling border line - it’s not at all long (9)
I believe the answer is:
ephemeral
'not at all long' is the definition.
(something ephemeral is short-lived)
'recording number of years controlling border line' is the wordplay.
'recording' becomes 'ep' (extended play vinyl record).
'number of years' becomes 'era'.
'controlling' is an insertion indicator.
'border' becomes 'hem' (I've seen this before).
'line' becomes 'l'.
'ep'+'era'='epera'
'epera' going around 'hem' is 'ephemera'.
'ephemera'+'l'='EPHEMERAL'
'it's' acts as a link.
(Other definitions for ephemeral that I've seen before include "Short-lived, passing quickly" , "short term gain" , "Fugitive" , "staying for a little while" , "just for a day?" .)