Here is the error log

2020-12-21T19:01:44.384+0000 I ASIO [NetworkInterfaceASIO-Replication-0] Failed to connect to mongodb-0.mongodb.default.svc.cluster.local

:27017 - HostUnreachable: Connection refused

2020-12-21T19:01:44.384+0000 I ASIO [NetworkInterfaceASIO-Replication-0] Dropping all pooled connections to mongodb-0.mongodb.default.svc

.cluster.local:27017 due to failed operation on a connection

2020-12-21T19:01:44.384+0000 I REPL [ReplicationExecutor] Error in heartbeat request to mongodb-0.mongodb.default.svc.cluster.local:27017

; HostUnreachable: Connection refused

Here is my yaml

ansible@sq-kube-01:~$ kubectl edit statefulset mongodb

• -v
• --replSet
• abacus
• --dbpath
• /data/db
• --logpath
• /var/log/mongodb/server.log
• --logRotate
• reopen
• --logappend
  command:
• mongod
  image: library/mongo:3.4.4
  imagePullPolicy: IfNotPresent
  name: mongodb
  ports:
• containerPort: 27017
  protocol: TCP
  resources:
  limits:
  cpu: "3"
  memory: 21Gi
  requests:
  cpu: 100m
  memory: 100Mi
  terminationMessagePath: /dev/termination-log
  terminationMessagePolicy: File
  volumeMounts:
• mountPath: /data/db
  name: mongodb
• mountPath: /var/log/mongodb
  name: logs
• env:
• name: MONGO_SIDECAR_POD_LABELS
  value: role=mongodb,environment=stage
• name: KUBERNETES_MONGO_SERVICE_NAME
  value: mongodb
• name: KUBE_NAMESPACE
  value: default
  image: cvallance/mongo-k8s-sidecar
  imagePullPolicy: IfNotPresent
  name: mongo-sidecar
  resources:
  limits:
  cpu: 300m
  memory: 500Mi

requests:
cpu: 100m
memory: 100Mi
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File

• args:
• proxy
• sidecar
• -v
• "2"
• --configPath
• /etc/istio/proxy
• --binaryPath
• /usr/local/bin/envoy
• --serviceCluster
• istio-proxy
• --drainDuration
• 45s
• --parentShutdownDuration
• 1m0s
• --discoveryAddress
• istio-pilot.istio-system:8080
• --discoveryRefreshDelay
• 1s
• --zipkinAddress
• zipkin.istio-system:9411
• --connectTimeout
• 10s
• --statsdUdpAddress
• istio-mixer.istio-system:9125
• --proxyAdminPort
• "15000"
  env:
• name: POD_NAME
  valueFrom:
  fieldRef:
  apiVersion: v1
  fieldPath: metadata.name
• name: POD_NAMESPACE
  valueFrom:
  fieldRef:
  apiVersion: v1

fieldPath: metadata.namespace

• name: INSTANCE_IP
  valueFrom:
  fieldRef:
  apiVersion: v1
  fieldPath: status.podIP
  image: docker.io/istio/proxy:0.2.6
  imagePullPolicy: IfNotPresent
  name: istio-proxy
  resources: {}
  securityContext:
  privileged: false
  readOnlyRootFilesystem: true
  runAsUser: 1337
  terminationMessagePath: /dev/termination-log
  terminationMessagePolicy: File
  volumeMounts:
• mountPath: /etc/istio/proxy
  name: istio-envoy
• mountPath: /etc/certs/
  name: istio-certs
  readOnly: true
  dnsPolicy: ClusterFirst
  imagePullSecrets:
• name: juniperregistrykey
  initContainers:
• args:
• -p
• "15001"
• -u
• "1337"
  image: docker.io/istio/proxy_init:0.2.6
  imagePullPolicy: IfNotPresent
  name: istio-init
  resources: {}
  securityContext:
  capabilities:
  add:
• NET_ADMIN
  privileged: true
  terminationMessagePath: /dev/termination-log
  terminationMessagePolicy: File
  nodeSelector:
  node: mongodb
  restartPolicy: Always

schedulerName: default-scheduler
securityContext: {}
serviceAccount: mongodb-serviceaccount
serviceAccountName: mongodb-serviceaccount
terminationGracePeriodSeconds: 10
volumes:

• emptyDir: {}
  name: configdir
• hostPath:
  path: /var/log/mongodb
  type: ""
  name: logs
• hostPath:
  path: /data/mongodb/data/db
  type: ""
  name: mongodb
• emptyDir:
  medium: Memory
  name: istio-envoy
• name: istio-certs
  secret:
  defaultMode: 420
  optional: true
  secretName: istio.mongodb-serviceaccount
  updateStrategy:
  rollingUpdate:
  partition: 0
  type: RollingUpdate
  status:
  collisionCount: 0
  currentReplicas: 3
  currentRevision: mongodb-86559f6fd5
  observedGeneration: 71
  readyReplicas: 3
  replicas: 3
  updateRevision: mongodb-86559f6fd5