Beam.smp 40GB memory usage

Hello dear friends, i actually have installed couchbase server version 4.5.0-2601 in two 2 server nodes, with a memcached bucket and i use it to handle php sessions, but the process beam.smp is taking 40GB memory usage of my actually physycal memory 120GB. It is normal ?

My data Ram quota is 4GB per server node 8GB total
My Node RAM Quota is 1GB per server node 2GB total

Any advice?

I will really appreciate your help.

Kind regards!!!