[Samba] Samba AD DC upgrade 4.4.5 to 4.10.4

[Trenta sis]

Hi,

I have an environment with a samba ad with debian 8 and samba 4.4.5, that
is working correctly but we have some issues, a memory leak an some
performance problems, at this moment with only one dc.

After reading wiki doc I'm trying to make uprade and also add a second dc,
my first suggestion will be create a second dc with samba 4.10.4 and join
to our actual dc as secondary, no fsm roles, but my question if this
replication can generate problems on main server, has peaks 80 and 90%,,,
and then test application with new dc and after that upgrade 4.4.5 to 4.10/

Is this right or what can be correct upgrade plan, with minimal or no
downtime and with less risk?

Also I have another dc environment that is working  and working also as
fileserver, I understand that in this case upgrade plan will be tge same,
right?

Thanks

Thanks