how to release memory? "memory usage 90 percent is over threshold 90 percent"

HI guys it's me again, well I have this situation, I have HA  Node one of them is over 90 percent of memory (it gone to standby)

 

 

How can I release Memory?

 

DFSA-SBC-NGNC02(configure)# sh he

sub-comand 'sh' not found or ambiguous

DFSA-SBC-NGNC02(configure)# exit
DFSA-SBC-NGNC02# sh health

Media Synchronized true
SIP Synchronized true
BGF Synchronized disabled
MGCP Synchronized disabled
H248 Synchronized disabled
XSERV Synchronized true
Config Synchronized true
Collect Synchronized disabled
Radius CDR Synchronized true
Rotated CDRs Synchronized true
IPSEC Synchronized disabled
Iked Synchronized disabled
Active Peer Address 169.254.1.1

Redundancy Protocol Process (v3):
State Standby
Health 25
Lowest Local Address 169.254.1.2:9090
1 peer(s) on 2 socket(s):