Exporter doesnt work with arbiter

[superset1]

Describe the bug
MongoDB Exporter 0.44.0 doesn't work wit arbiter in mongodb replicaset cluster.
Last worked version with arbiter 0.11.2!

To Reproduce

1. Setup mongodb exporter on arbiter node
2. Create systemd unit /etc/systemd/system/mongodb-exporter.service;

# Ansible managed

[Unit]
Description=Prometheus exporter for MongoDB (https://github.com/percona/mongodb_exporter)
After=network.target mongod.service
Wants=network.target

[Service]
Type=simple
RestartSec=5s
Restart=on-failure
User=mongodb-exporter
Group=mongodb
ExecStart=/usr/local/bin/mongodb-exporter --collect-all --discovering-mode --compatible-mode --mongodb.direct-connect --mongodb.uri="mongodb://mongodbexporter:djskrbbksbdf234vK@127.0.0.1:27017/admin?tls=true&tlsCertificateKeyFile=/etc/ssl/mongodb.pem&tlsCAFile=/etc/ssl/mongodb-ca.pem"
ExecStop=/bin/kill -s SIGINT $MAINPID

[Install]
WantedBy=multi-user.target

3. systemctl start mongodb-exporter.service

Expected behavior
Work like in version 0.11.2

Logs

Jun 05 19:50:53 test-mongo-cl1-3 systemd[1]: Started Prometheus exporter for MongoDB (https://github.com/percona/mongodb_exporter).
Jun 05 19:50:53 test-mongo-cl1-3 mongodb-exporter[48357]: time="2025-06-05T19:50:53+03:00" level=error msg="Cannot connect to MongoDB: cannot connect to MongoDB: connection() error occurred during connection handshake: auth error: sasl conversation error: unable to authenticate using mechanism \"SCRAM-SHA-1\": (AuthenticationFailed) Authentication failed."
Jun 05 19:51:02 test-mongo-cl1-3 mongodb-exporter[48357]: time="2025-06-05T19:51:02+03:00" level=error msg="Cannot connect to MongoDB: cannot connect to MongoDB: connection() error occurred during connection handshake: auth error: sasl conversation error: unable to authenticate using mechanism \"SCRAM-SHA-1\": (AuthenticationFailed) Authentication failed."

Environment

• Operating System: Debian GNU/Linux 11 (bullseye)
• Kernel: Linux 6.1.0-0.deb11.21-amd64,
• environment (VM)
• MongoDB version 7.0.18

Additional context
I tried:

• ExecStart=/usr/local/bin/mongodb-exporter --collect-all --discovering-mode --compatible-mode --mongodb.direct-connect --mongodb.uri="mongodb://mongodbexporter:djskrbbksbdf234vK@127.0.0.1:27017/admin?tls=true&tlsCertificateKeyFile=/etc/ssl/mongodb.pem&tlsCAFile=/etc/ssl/mongodb-ca.pem"
• ExecStart=/usr/local/bin/mongodb-exporter --collect-all --discovering-mode --compatible-mode --mongodb.direct-connect --mongodb.uri="mongodb://mongodbexporter:djskrbbksbdf234vK@127.0.0.1:27017/admin"
• ExecStart=/usr/local/bin/mongodb-exporter --mongodb.direct-connect --mongodb.uri="mongodb://mongodbexporter:djskrbbksbdf234vK@127.0.0.1:27017/admin"

Not worked.

cat /etc/mongod.conf

# Ansible managed

net:
  bindIp: 0.0.0.0
  ipv6: false
  maxIncomingConnections: 65536
  port: 27017
  tls:
    mode: requireTLS
    certificateKeyFile: /etc/ssl/mongodb.pem
    CAFile: /etc/ssl/mongodb-ca.pem
    allowConnectionsWithoutCertificates: true

processManagement:
  fork: false

replication:
  oplogSizeMB: 4096
  replSetName: rs01

security:
  authorization: enabled
  keyFile: /etc/mongodb-keyfile
  javascriptEnabled: false

storage:
  dbPath: /data/db
  directoryPerDB: false
  engine: wiredTiger
  journal:
    commitIntervalMs: 100
  wiredTiger:
    engineConfig:
      directoryForIndexes: false

systemLog:
  destination: file
  logAppend: true
  logRotate: rename
  path: /var/log/mongodb/mongod.log
  verbosity: 0

operationProfiling:
  slowOpThresholdMs: 100
  mode: off

[idoqo]

• Does the same working version (0.11.2) works for MongoDB v7.0.18?
• can you try to pass in just the host and port to mongodb.uri (i.e., without the username and password part)? As far as I remember, arbiters do not store data and might fail authentication attempts.

[superset1]

Yes, 0.11.2 works with all versions of mongodb, but my question is different. Why doesn't MongoDB Exporter 0.44.0 work with arbiter?