I'm trying to perform a full backup of mongodb using the following command:

mongodump --uri="mongodb://mongo.database.svc:27017/?replicaSet=rs0"  --oplog --out=/mnt/k8sMount/mongodb-dump/

Note: Here the uri specified is a mongodb headless service in kubernetes.

But this command after few minutes results in error:

2021-10-08T02:55:19.021+0000    Failed: error counting admin.system.version: not master and slaveOk=false

I have gone through multiple forums regarding this error, but did not find relevant solution. Any suggestions would be helpful.

Note: When i exec to the mongodb primary pod and run the command(here i dont specify the uri parameter), it works fine without any issues.

Mongodb version: 4