listen=tcp:SIP:RPC_PORT  

SH_MEM=5012
PRIV_MEM=264

System Specification : 24 GB RAM, 12 CPUs

Sometimes kamailio  radomly stop processing the requests or give no response on  new requests recevied on virtual ips and as well it did't show any error in syslog. 

To monitor the kamailio memory I used promethues (https://github.com/florentchauveau/kamailio_exporter)

The moment kamailio stop processing the requests it also stop responding to kamailio exporter and scrap request get timeout.  i.e error log on console 

After getting first timeout occurrence of  kamailio-exporter scrap request, kamailio processed sip messages for almost 30 seconds then completly stop replying to any message.  But it keep replying to option message arrive on different port from keepalived script. 

Stats :

Active dialog: 75 

Shared memory used: 150 MB

Kamailio Installed version :

kamailio -v
version: kamailio 5.4.1 (x86_64/linux) 2ca223
flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLACKLIST, HAVE_RESOLV_RES, TLS_PTHREAD_MUTEX_SHARED
ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB
poll method support: poll, epoll_lt, epoll_et, sigio_rt, select.
id: 2ca223
compiled on 12:51:24 Sep 21 2020 with gcc 6.3.0

M Arqum