Symptom:
Note the running times of vpfa and vpp - vpp just restarted, while vpfa is running for about 2 hours.
VPFA did not reconfigure VPP.


systemctl status vpfa
● vpfa.service - vector packet forwarding agent
   Loaded: loaded (/usr/lib/systemd/system/vpfa.service; enabled; vendor preset: disabled)
   Active: active (running) since Wed 2018-01-31 13:25:23 PST; 1h 59min ago
 Main PID: 40730 (python)
   CGroup: /system.slice/vpfa.service
           └─40730 /opt/cisco/package/sr/vpfa/bin/python -u -m vsocrc.vpfa.vpfa_restconf_server

systemctl status vpp
● vpp.service - Vector Packet Processing Process
   Loaded: loaded (/usr/lib/systemd/system/vpp.service; enabled; vendor preset: disabled)
   Active: active (running) since Wed 2018-01-31 15:12:14 PST; 12min ago
  Process: 43824 ExecStartPre=/sbin/modprobe uio_pci_generic (code=exited, status=0/SUCCESS)
  Process: 43821 ExecStartPre=/bin/rm -f /dev/shm/db /dev/shm/global_vm /dev/shm/vpe-api (code=exited, status=0/SUCCESS)

Conditions:
If VPP crashes or restarts abnormally