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mongodb adds an example of an arbiter node method

  • 2020-06-15 10:27:56
  • OfStack

preface

When replica set of mongodb was created, it was made 1 master and 2 slave, not 1 master and 1 slave. Here we delete one point from replica set and add it to replica set as a mediation node:

1. Initial state: 


shard1ReplSet:PRIMARY> rs.status();rs.status();
{
  "set" : "shard1ReplSet",
  "date" : ISODate("2017-02-21T07:48:03.058Z"),
  "myState" : 1,
  "term" : NumberLong(1),
  "heartbeatIntervalMillis" : NumberLong(2000),
  "optimes" : {
    "lastCommittedOpTime" : {
      "ts" : Timestamp(0, 0),
      "t" : NumberLong(-1)
    },
    "appliedOpTime" : {
      "ts" : Timestamp(1487663274, 1),
      "t" : NumberLong(1)
    },
    "durableOpTime" : {
      "ts" : Timestamp(1487587982, 1),
      "t" : NumberLong(-1)
    }
  },
  "members" : [
    {
      "_id" : 0,
      "name" : "10.13.0.130:22001",
      "health" : 1,
      "state" : 1,
      "stateStr" : "PRIMARY",
      "uptime" : 76672,
      "optime" : {
        "ts" : Timestamp(1487663274, 1),
        "t" : NumberLong(1)
      },
      "optimeDate" : ISODate("2017-02-21T07:47:54Z"),
      "electionTime" : Timestamp(1487587993, 1),
      "electionDate" : ISODate("2017-02-20T10:53:13Z"),
      "configVersion" : 1,
      "self" : true
    },
    {
      "_id" : 1,
      "name" : "10.13.0.131:22001",
      "health" : 1,
      "state" : 2,
      "stateStr" : "SECONDARY",
      "uptime" : 75300,
      "optime" : {
        "ts" : Timestamp(1487663274, 1),
        "t" : NumberLong(1)
      },
      "optimeDurable" : {
        "ts" : Timestamp(1487587982, 1),
        "t" : NumberLong(-1)
      },
      "optimeDate" : ISODate("2017-02-21T07:47:54Z"),
      "optimeDurableDate" : ISODate("2017-02-20T10:53:02Z"),
      "lastHeartbeat" : ISODate("2017-02-21T07:48:02.150Z"),
      "lastHeartbeatRecv" : ISODate("2017-02-21T07:48:02.215Z"),
      "pingMs" : NumberLong(0),
      "syncingTo" : "10.13.0.132:22001",
      "configVersion" : 1
    },
    {
      "_id" : 2,
      "name" : "10.13.0.132:22001",
      "health" : 1,
      "state" : 2,
      "stateStr" : "SECONDARY",
      "uptime" : 75300,
      "optime" : {
        "ts" : Timestamp(1487663274, 1),
        "t" : NumberLong(1)
      },
      "optimeDurable" : {
        "ts" : Timestamp(1487587982, 1),
        "t" : NumberLong(-1)
      },
      "optimeDate" : ISODate("2017-02-21T07:47:54Z"),
      "optimeDurableDate" : ISODate("2017-02-20T10:53:02Z"),
      "lastHeartbeat" : ISODate("2017-02-21T07:48:02.889Z"),
      "lastHeartbeatRecv" : ISODate("2017-02-21T07:48:01.503Z"),
      "pingMs" : NumberLong(0),
      "syncingTo" : "10.13.0.130:22001",
      "configVersion" : 1
    }
  ],
  "ok" : 1
}
shard1ReplSet:PRIMARY> 
shard1ReplSet:PRIMARY> 
shard1ReplSet:PRIMARY> 
shard1ReplSet:PRIMARY>

2. Delete nodes: 


shard1ReplSet:PRIMARY> rs.remove("10.13.0.132:22001"); rs.remove("10.13.0.132:22001"); 
{ "ok" : 1 }
shard1ReplSet:PRIMARY> rs.status();rs.status();
{
  "set" : "shard1ReplSet",
  "date" : ISODate("2017-02-21T07:50:52.934Z"),
  "myState" : 1,
  "term" : NumberLong(1),
  "heartbeatIntervalMillis" : NumberLong(2000),
  "optimes" : {
    "lastCommittedOpTime" : {
      "ts" : Timestamp(0, 0),
      "t" : NumberLong(-1)
    },
    "appliedOpTime" : {
      "ts" : Timestamp(1487663447, 1),
      "t" : NumberLong(1)
    },
    "durableOpTime" : {
      "ts" : Timestamp(1487587982, 1),
      "t" : NumberLong(-1)
    }
  },
  "members" : [
    {
      "_id" : 0,
      "name" : "10.13.0.130:22001",
      "health" : 1,
      "state" : 1,
      "stateStr" : "PRIMARY",
      "uptime" : 76841,
      "optime" : {
        "ts" : Timestamp(1487663447, 1),
        "t" : NumberLong(1)
      },
      "optimeDate" : ISODate("2017-02-21T07:50:47Z"),
      "electionTime" : Timestamp(1487587993, 1),
      "electionDate" : ISODate("2017-02-20T10:53:13Z"),
      "configVersion" : 2,
      "self" : true
    },
    {
      "_id" : 1,
      "name" : "10.13.0.131:22001",
      "health" : 1,
      "state" : 2,
      "stateStr" : "SECONDARY",
      "uptime" : 75470,
      "optime" : {
        "ts" : Timestamp(1487663447, 1),
        "t" : NumberLong(1)
      },
      "optimeDurable" : {
        "ts" : Timestamp(1487587982, 1),
        "t" : NumberLong(-1)
      },
      "optimeDate" : ISODate("2017-02-21T07:50:47Z"),
      "optimeDurableDate" : ISODate("2017-02-20T10:53:02Z"),
      "lastHeartbeat" : ISODate("2017-02-21T07:50:51.182Z"),
      "lastHeartbeatRecv" : ISODate("2017-02-21T07:50:52.212Z"),
      "pingMs" : NumberLong(0),
      "configVersion" : 2
    }
  ],
  "ok" : 1
}
shard1ReplSet:PRIMARY> 
shard1ReplSet:PRIMARY> 
shard1ReplSet:PRIMARY>

3. Add to arbiter node: 


shard1ReplSet:PRIMARY> rs.addArb("10.13.0.132:22001");rs.addArb("10.13.0.132:22001");
{ "ok" : 1 }
shard1ReplSet:PRIMARY> 
shard1ReplSet:PRIMARY> rs.status();rs.status();
{
  "set" : "shard1ReplSet",
  "date" : ISODate("2017-02-21T07:54:05.161Z"),
  "myState" : 1,
  "term" : NumberLong(1),
  "heartbeatIntervalMillis" : NumberLong(2000),
  "optimes" : {
    "lastCommittedOpTime" : {
      "ts" : Timestamp(0, 0),
      "t" : NumberLong(-1)
    },
    "appliedOpTime" : {
      "ts" : Timestamp(1487663637, 1),
      "t" : NumberLong(1)
    },
    "durableOpTime" : {
      "ts" : Timestamp(1487587982, 1),
      "t" : NumberLong(-1)
    }
  },
  "members" : [
    {
      "_id" : 0,
      "name" : "10.13.0.130:22001",
      "health" : 1,
      "state" : 1,
      "stateStr" : "PRIMARY",
      "uptime" : 77034,
      "optime" : {
        "ts" : Timestamp(1487663637, 1),
        "t" : NumberLong(1)
      },
      "optimeDate" : ISODate("2017-02-21T07:53:57Z"),
      "electionTime" : Timestamp(1487587993, 1),
      "electionDate" : ISODate("2017-02-20T10:53:13Z"),
      "configVersion" : 3,
      "self" : true
    },
    {
      "_id" : 1,
      "name" : "10.13.0.131:22001",
      "health" : 1,
      "state" : 2,
      "stateStr" : "SECONDARY",
      "uptime" : 75662,
      "optime" : {
        "ts" : Timestamp(1487663637, 1),
        "t" : NumberLong(1)
      },
      "optimeDurable" : {
        "ts" : Timestamp(1487587982, 1),
        "t" : NumberLong(-1)
      },
      "optimeDate" : ISODate("2017-02-21T07:53:57Z"),
      "optimeDurableDate" : ISODate("2017-02-20T10:53:02Z"),
      "lastHeartbeat" : ISODate("2017-02-21T07:54:03.210Z"),
      "lastHeartbeatRecv" : ISODate("2017-02-21T07:54:02.211Z"),
      "pingMs" : NumberLong(0),
      "configVersion" : 3
    },
    {
      "_id" : 2,
      "name" : "10.13.0.132:22001",
      "health" : 1,
      "state" : 7,
      "stateStr" : "ARBITER",
      "uptime" : 5,
      "lastHeartbeat" : ISODate("2017-02-21T07:54:03.214Z"),
      "lastHeartbeatRecv" : ISODate("2017-02-21T07:54:02.274Z"),
      "pingMs" : NumberLong(0),
      "configVersion" : 3
    }
  ],
  "ok" : 1
}
shard1ReplSet:PRIMARY>

Note 1 After mongodb 3.4, arbiter is not supported, although config server is required to be replica set.

When added, an error will be reported: 


cfgReplSet:PRIMARY> rs.addArb("10.13.0.132:21000");rs.addArb("10.13.0.132:21000");
{
  "ok" : 0,
  "errmsg" : "Arbiters are not allowed in replica set configurations being used for config servers",
  "code" : 103,
  "codeName" : "NewReplicaSetConfigurationIncompatible"
}
cfgReplSet:PRIMARY>

Note 2: rs. reconfig() can also be operated with a similar effect to re. remove+ rs. addArb

conclusion

The above is all about mongodb add arbiter node, I hope the content of this article can bring you a certain help in your study or work, if you have any questions, you can leave a message to communicate.

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