Data are not replicated between MongoDB instance (replication in docker compose)

[MalloryLP (Mallory LEHUAULT-PARC)]

Hi, i’m trying to setup a replicat between 3 MongoDB instance in a Docker environnement. All instances of MongoDB seems to works well. I’m able to be connected to thoses instances with Compass. The replicat seems also to works, a primary is elected and nothing in the logs altert me of a potential problem.

Here is the rs.conf() output:

{
  _id: 'rs0',
  version: 1,
  term: 3,
  members: [
    {
      _id: 0,
      host: 'mongo1:30001',
      arbiterOnly: false,
      buildIndexes: true,
      hidden: false,
      priority: 1,
      tags: {},
      secondaryDelaySecs: Long("0"),
      votes: 1
    },
    {
      _id: 1,
      host: 'mongo2:30002',
      arbiterOnly: false,
      buildIndexes: true,
      hidden: false,
      priority: 1,
      tags: {},
      secondaryDelaySecs: Long("0"),
      votes: 1
    },
    {
      _id: 2,
      host: 'mongo3:30003',
      arbiterOnly: false,
      buildIndexes: true,
      hidden: false,
      priority: 1,
      tags: {},
      secondaryDelaySecs: Long("0"),
      votes: 1
    }
  ],
  protocolVersion: Long("1"),
  writeConcernMajorityJournalDefault: true,
  settings: {
    chainingAllowed: true,
    heartbeatIntervalMillis: 2000,
    heartbeatTimeoutSecs: 10,
    electionTimeoutMillis: 10000,
    catchUpTimeoutMillis: -1,
    catchUpTakeoverDelayMillis: 30000,
    getLastErrorModes: {},
    getLastErrorDefaults: { w: 1, wtimeout: 0 },
    replicaSetId: ObjectId("646dd34139abd7f32bb09ea1")
  }
}

And the rs.status():

 {
  set: 'rs0',
  date: 2023-05-24T10:01:40.074Z,
  myState: 2,
  term: Long("3"),
  syncSourceHost: 'mongo2:30002',
  syncSourceId: 1,
  heartbeatIntervalMillis: Long("2000"),
  majorityVoteCount: 2,
  writeMajorityCount: 2,
  votingMembersCount: 3,
  writableVotingMembersCount: 3,
  optimes: {
    lastCommittedOpTime: { ts: Timestamp({ t: 1684922497, i: 1 }), t: Long("3") },
    lastCommittedWallTime: 2023-05-24T10:01:37.139Z,
    readConcernMajorityOpTime: { ts: Timestamp({ t: 1684922497, i: 1 }), t: Long("3") },
    appliedOpTime: { ts: Timestamp({ t: 1684922497, i: 1 }), t: Long("3") },
    durableOpTime: { ts: Timestamp({ t: 1684922497, i: 1 }), t: Long("3") },
    lastAppliedWallTime: 2023-05-24T10:01:37.139Z,
    lastDurableWallTime: 2023-05-24T10:01:37.139Z
  },
  lastStableRecoveryTimestamp: Timestamp({ t: 1684922447, i: 1 }),
  electionParticipantMetrics: {
    votedForCandidate: true,
    electionTerm: Long("3"),
    lastVoteDate: 2023-05-24T09:30:57.058Z,
    electionCandidateMemberId: 1,
    voteReason: '',
    lastAppliedOpTimeAtElection: { ts: Timestamp({ t: 1684920580, i: 1 }), t: Long("2") },
    maxAppliedOpTimeInSet: { ts: Timestamp({ t: 1684920580, i: 1 }), t: Long("2") },
    priorityAtElection: 1,
    newTermStartDate: 2023-05-24T09:30:57.071Z,
    newTermAppliedDate: 2023-05-24T09:30:57.349Z
  },
  members: [
    {
      _id: 0,
      name: 'mongo1:30001',
      health: 1,
      state: 2,
      stateStr: 'SECONDARY',
      uptime: 1846,
      optime: [Object],
      optimeDurable: [Object],
      optimeDate: 2023-05-24T10:01:37.000Z,
      optimeDurableDate: 2023-05-24T10:01:37.000Z,
      lastAppliedWallTime: 2023-05-24T10:01:37.139Z,
      lastDurableWallTime: 2023-05-24T10:01:37.139Z,
      lastHeartbeat: 2023-05-24T10:01:38.263Z,
      lastHeartbeatRecv: 2023-05-24T10:01:38.266Z,
      pingMs: Long("0"),
      lastHeartbeatMessage: '',
      syncSourceHost: 'mongo2:30002',
      syncSourceId: 1,
      infoMessage: '',
      configVersion: 1,
      configTerm: 3
    },
    {
      _id: 1,
      name: 'mongo2:30002',
      health: 1,
      state: 1,
      stateStr: 'PRIMARY',
      uptime: 1846,
      optime: [Object],
      optimeDurable: [Object],
      optimeDate: 2023-05-24T10:01:37.000Z,
      optimeDurableDate: 2023-05-24T10:01:37.000Z,
      lastAppliedWallTime: 2023-05-24T10:01:37.139Z,
      lastDurableWallTime: 2023-05-24T10:01:37.139Z,
      lastHeartbeat: 2023-05-24T10:01:38.263Z,
      lastHeartbeatRecv: 2023-05-24T10:01:39.779Z,
      pingMs: Long("0"),
      lastHeartbeatMessage: '',
      syncSourceHost: '',
      syncSourceId: -1,
      infoMessage: '',
      electionTime: Timestamp({ t: 1684920657, i: 1 }),
      electionDate: 2023-05-24T09:30:57.000Z,
      configVersion: 1,
      configTerm: 3
    },
    {
      _id: 2,
      name: 'mongo3:30003',
      health: 1,
      state: 2,
      stateStr: 'SECONDARY',
      uptime: 1849,
      optime: [Object],
      optimeDate: 2023-05-24T10:01:37.000Z,
      lastAppliedWallTime: 2023-05-24T10:01:37.139Z,
      lastDurableWallTime: 2023-05-24T10:01:37.139Z,
      syncSourceHost: 'mongo2:30002',
      syncSourceId: 1,
      infoMessage: '',
      configVersion: 1,
      configTerm: 3,
      self: true,
      lastHeartbeatMessage: ''
    }
  ],
  ok: 1,
  '$clusterTime': {
    clusterTime: Timestamp({ t: 1684922497, i: 1 }),
    signature: {
      hash: Binary(Buffer.from("71462de63bcd84a20b0fd37f9f8ecbeeeeff4646", "hex"), 0),
      keyId: Long("7236672499625230342")
    }
  },
  operationTime: Timestamp({ t: 1684922497, i: 1 })
}

I think i’m missing somethings in the initiatial parameters but i d’ont know what.
Any help will be useful.

Thanks,
Mallory LP.

[Kobe_W]

What happens if you make a majority write?

[MalloryLP (Mallory LEHUAULT-PARC)]

I have added w=majority in the URI but nothing new.
I think I have misunderstood the way to connect to the replica via MongoDBCompass, I’m using this URI :

mongodb://******:******@XX.XX.XX.XX:30001/?replicaSet=rs0&directConnection=true&authMechanism=DEFAULT&authSource=admin&w=majority

But shouldn’t I use this URI with the 3 MongoDB instances ?

mongodb://******:******@XX.XX.XX.XX:30001,XX.XX.XX.XX:30002,XX.XX.XX.XX:30003/?replicaSet=rs0&authMechanism=DEFAULT&authSource=admin&w=majority

When i try this URI, I have this error :

getaddrinfo ENOTFOUND mongo1

Here are the logs :

mongo2                        | {"t":{"$date":"2023-05-25T07:25:54.887+00:00"},"s":"I",  "c":"NETWORK",  "id":22943,   "ctx":"listener","msg":"Connection accepted","attr":{"remote":"YY.YY.YY.YY:59230","uuid":"fcdd2403-e65a-4572-a505-90a5865b0650","connectionId":70,"connectionCount":13}}
mongo3                        | {"t":{"$date":"2023-05-25T07:25:54.887+00:00"},"s":"I",  "c":"NETWORK",  "id":22943,   "ctx":"listener","msg":"Connection accepted","attr":{"remote":"YY.YY.YY.YY:52958","uuid":"5be994ac-1641-4b4f-a6c2-d172dd90125a","connectionId":38,"connectionCount":9}}
mongo1                        | {"t":{"$date":"2023-05-25T07:25:54.886+00:00"},"s":"I",  "c":"NETWORK",  "id":22943,   "ctx":"listener","msg":"Connection accepted","attr":{"remote":"YY.YY.YY.YY:36398","uuid":"3403d40f-9766-4897-80e6-7ee9b10cf35d","connectionId":50,"connectionCount":7}}
mongo2                        | {"t":{"$date":"2023-05-25T07:25:54.890+00:00"},"s":"I",  "c":"NETWORK",  "id":51800,   "ctx":"conn70","msg":"client metadata","attr":{"remote":"YY.YY.YY.YY:59230","client":"conn70","doc":{"driver":{"name":"nodejs","version":"5.1.0"},"os":{"type":"Windows_NT","name":"win32","architecture":"x64","version":"10.0.22621"},"platform":"Node.js v16.17.1, LE (unified)|Node.js v16.17.1, LE (unified)","application":{"name":"MongoDB
Compass"}}}}
mongo3                        | {"t":{"$date":"2023-05-25T07:25:54.890+00:00"},"s":"I",  "c":"NETWORK",  "id":51800,   "ctx":"conn38","msg":"client metadata","attr":{"remote":"YY.YY.YY.YY:52958","client":"conn38","doc":{"driver":{"name":"nodejs","version":"5.1.0"},"os":{"type":"Windows_NT","name":"win32","architecture":"x64","version":"10.0.22621"},"platform":"Node.js v16.17.1, LE (unified)|Node.js v16.17.1, LE (unified)","application":{"name":"MongoDB
Compass"}}}}
mongo1                        | {"t":{"$date":"2023-05-25T07:25:54.891+00:00"},"s":"I",  "c":"NETWORK",  "id":51800,   "ctx":"conn50","msg":"client metadata","attr":{"remote":"YY.YY.YY.YY:36398","client":"conn50","doc":{"driver":{"name":"nodejs","version":"5.1.0"},"os":{"type":"Windows_NT","name":"win32","architecture":"x64","version":"10.0.22621"},"platform":"Node.js v16.17.1, LE (unified)|Node.js v16.17.1, LE (unified)","application":{"name":"MongoDB
Compass"}}}}
mongo2                        | {"t":{"$date":"2023-05-25T07:25:54.946+00:00"},"s":"I",  "c":"NETWORK",  "id":22944,   "ctx":"conn70","msg":"Connection ended","attr":{"remote":"YY.YY.YY.YY:59230","uuid":"fcdd2403-e65a-4572-a505-90a5865b0650","connectionId":70,"connectionCount":12}}
mongo1                        | {"t":{"$date":"2023-05-25T07:25:54.946+00:00"},"s":"I",  "c":"NETWORK",  "id":22944,   "ctx":"conn50","msg":"Connection ended","attr":{"remote":"YY.YY.YY.YY:36398","uuid":"3403d40f-9766-4897-80e6-7ee9b10cf35d","connectionId":50,"connectionCount":6}}
mongo3                        | {"t":{"$date":"2023-05-25T07:25:54.947+00:00"},"s":"I",  "c":"NETWORK",  "id":22944,   "ctx":"conn38","msg":"Connection ended","attr":{"remote":"YY.YY.YY.YY:52958","uuid":"5be994ac-1641-4b4f-a6c2-d172dd90125a","connectionId":38,"connectionCount":8}}

Thanks for your reply,
MalloryLP.

[steevej (Steeve Juneau)]

Using

@MalloryLP

directConnection=true

is probably wrong when your mongod is running on docker unless your client is connecting from the same docker instance.

@MalloryLP

But shouldn’t I use this URI with the 3 MongoDB instances ?

You do not really have to use all of them. When you connect with rs0, the driver get the replica set info from the node/nodes it connects, then try to reconnect to all members.

The fact that you get ENOTFOUND on mongo1 seems to indicate that some docker config is missing or not accessible from where you try to connect.

[MalloryLP (Mallory LEHUAULT-PARC)]

I have tried serval connections string and i can connect to all mongodb instance in the replica with directConnection=true form external client but when I don’t use this parameter I can’t. As you can see in the logs, the connection is detected.
I will investigate in Docker configuration.

[chris (Chris Dellaway)]

Getting error "getaddrinfo ENOTFOUND mongo1" when trying to reach replication cluster on Docker through MongoDB Compass on Windows 10

Really this comes down to the docker networking namespace and being able to resolve the hostnames. It also relates to the replicaset discovery when a client connects, the hostnames and ports returned by db.hello() is what the client will try and connect to. This would work if it wasn’t for docker. If you had multiple mongod on your local environment for example. This is how I have have run a replset in docker and be able to connect from a local application.