sluggish server on Linux

Machine specs:

ubuntu 18.04 LTS

Dual Xeon L5420

16 gigs ram

500 gig storage

106 machines

 Ram usage has absolutely exploded and it now sits at 4.43 GiB.  I have had to restart the entire box 3 times due to the SC services actually chewing up all ram which of course brings the system either to it knees causing horrendously slow performance or the machine just hangs completely.  Killing the process doesn't free the ram like it should so this tells me there's a bad memory leak.  Also when i disconnect from a session..it takes a minimum of one minute for the server to acknowledge the disconnect.  otherwise I cannot connect to another machine(i do have one seat license)..this used to be within a second or two i could switch to another machine.