Swap is not utilized

Hello,

We have production memsql cluster with1 master aggregator, 3 aggregator and 30 leaf node. Leaf node memory is 128G. When we try to execute a query it return following error.
685841552204 2019-09-12 05:34:21.785 ERROR: Socket::Send (ssl = 1) failed with Broken pipe (32)
685841552266 2019-09-12 05:34:21.785 ERROR: Socket::Send (ssl = 1) failed with Broken pipe (32)

We have found 2 nodes memory completly exhausted. Upon checking we have found the swap space is not used.

:~$ free -g
total used free shared buff/cache available
Mem: 125 116 2 0 7 5
Swap: 31 0 31

Can someone let me know why memsql is not utilizing the swap memory?

Regards

Can someone give an update on this question?