fts exit with status 1 observed in centos longevity

centos longevity - 6.5.0-2647 - following exit observed:

2019-03-21T19:57:22.093-07:00, ns_log:0:info:message(ns_1@172.23.96.253) - Service 'fts' exited with status 1. Restarting. Messages:
2019-03-21T19:57:19.985-07:00 [INFO] main: registered bleve stores
2019-03-21T19:57:19.985-07:00 [INFO] boltdb
2019-03-21T19:57:19.985-07:00 [INFO] metrics
2019-03-21T19:57:19.985-07:00 [INFO] goleveldb
2019-03-21T19:57:19.985-07:00 [INFO] moss
2019-03-21T19:57:19.985-07:00 [INFO] gtreap
2019-03-21T19:57:19.985-07:00 [INFO] main: curr dir: "/opt/couchbase/var/lib/couchbase"
2019-03-21T19:57:19.985-07:00 [INFO] main: data dir: "/data/@fts"
2019-03-21T19:57:19.985-07:00 [INFO] cfg_metakv: RunObserveChildren, err: Get http://127.0.0.1:8091/_metakv/fts/cbgt/cfg/?feed=continuous: CBAuth database is stale: last reason: dial tcp 127.0.0.1:8091: connect: connection refused
2019-03-21T19:57:19.985-07:00 [INFO] app_herder: memQuota: 20093952000, appQuota: 20093952000, indexQuota: 15070464000, queryQuota: 18084556800
2019-03-21T19:57:19.986-07:00 [FATA] Get http://127.0.0.1:8091/_metakv/fts/cbgt/cfg/nodeDefs-known/: CBAuth database is stale: last reason: dial tcp 127.0.0.1:8091: connect: connection refused – main.main() at main.go:223

logs: https://supportal.couchbase.com/snapshot/9ed518550dd44fdf5206a5c40c8f12df::3
cluster: 172.23.108.103:8091
console: http://172.23.109.231/job/centos-systest-launcher/1738/console