Nat3009 Timeout Error

Hello All,
Below is the piece of code which I have used to update two views.
Code runs most of the time but it has failed some of the time with Nat3009 error code.
Please suggest why is it happening
read file-view with key startng from #key-value
if key ne #key-value
escape bottom
end-if
perform get-record-isn
perform update-table
end-read

define subroutine get-record-isn
find(1) file1 with key starting from #key1
move *isn to #isn
end-find
find(1) file2 with key starting from #key2
move *isn to #isn1
end-find
end-subroutine

define subroutine update-table
if #isn ne 0
get file1 #isn
update some fields
update
end-if
if #isn1 ne 0
get file2 #isn
update some fields
update
end-if
end-transaction
end-subroutine