Mongodb replica set add/delete node method

Replica set multi-server master/slave, add and delete nodes, which are common. The following describes how to add or delete a node in detail.

1. Use rs. reconfig to add and delete nodes

1. Add nodes

The code is as follows:	Copy code
Repmore: PRIMARY> config = {_ id: "repmore", members: [{_ id: 0, host: '2017. 0.0.1: 100', priority: 2}, {_ id: 1, host: '123. 0.0.1: 27018 ', priority: 1}]}; // add a node Repmore: PRIMARY> rs. reconfig (config); // Make the configuration take effect Repmore: PRIMARY> rs. status (); // view node status

Node added successfully.

Note: replSet of the newly added node must be the same as that of other nodes.

2. Delete a node (it is best to close the node to be deleted before deleting the node, and then delete it by running the rs. remove command)

The code is as follows:	Copy code
Repmore: PRIMARY> config = {_ id: "repmore", members: [{_ id: 0, host: '2017. 0.0.1: 27017 ', priority: 2}]}; // delete a node Repmore: PRIMARY> rs. reconfig (config); // Make the configuration take effect Repmore: PRIMARY> rs. status (); // view node status

2. Use rs. add and rs. remove to add and delete nodes.

The code is as follows:	Copy code
Repmore: PRIMARY> rs. add ("127.0.0.1: 27018"); // add a node Repmore: PRIMARY> rs. remove ("127.0.0.1: 27018"); // delete a section

Note: using rs. add and rs. remove does not require rs. reconfig to take effect.

Finally, I will add a standard process for you to delete nodes.

The operations are as follows:
  

The code is as follows:

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-- 1 view the current Replica Set configuration [Mongo @ redhatB mongodb] $ mongo 127.0.0.1: 27018 MongoDB shell version: 2.2.1 Connecting to: 127.0.0.1: 27018/test Rs0: PRIMARY> rs. conf (); { "_ Id": "rs0 ", "Version": 4, "Members ":[                 { "_ Id": 0, "Host": "redhatB.example.com: 27018" },                 { "_ Id": 1, "Host": "redhatB.example.com: 27019" },                 { "_ Id": 2, "Host": "redhatB.example.com: 27020" },                 { "_ Id": 3, "Host": "redhatB.example.com: 27021"                 }         ] }    Note: "_ id": 3. -- 2 close the 27021 Node Service [Mongo @ redhatB data04] $ ps-ef | grep 27021 Mongo 11733 1 0? At 00:00:15, mongod-f/pgdata_xc/mongodb/data04/mongodb_27021.conf Mongo 14422 2953 0 00:00:00 pts/0 mongo 127.0.0.1: 27021 Mongo 14490 4027 0 00:00:00 pts/1 grep 27021 [Mongo @ redhatB data04] $ kill 11733    -- 3 view the status of the replica set Rs0: PRIMARY> rs. status (); { "Set": "rs0 ", "Date": ISODate ("2012-11-22T13: 57: 15Z "), "MyState": 1, "Members ":[                 { "_ Id": 0, "Name": "redhatB.example.com: 27018 ", "Health": 1, "State": 1, "StateStr": "PRIMARY ", "Uptime": 21279, "Optime": Timestamp (1353589624000, 1 ), "OptimeDate": ISODate ("2012-11-22T13: 07: 04Z "), "Self": true },                 { "_ Id": 1, "Name": "redhatB.example.com: 27019 ", "Health": 1, "State": 2, "StateStr": "SECONDARY ", "Uptime": 18908, "Optime": Timestamp (1353589624000, 1 ), "OptimeDate": ISODate ("2012-11-22T13: 07: 04Z "), "LastHeartbeat": ISODate ("2012-11-22T13: 57: 13Z "), "PingMs": 0 },                 { "_ Id": 2, "Name": "redhatB.example.com: 27020 ", "Health": 1, "State": 2, "StateStr": "SECONDARY ", "Uptime": 18900, "Optime": Timestamp (1353589624000, 1 ), "OptimeDate": ISODate ("2012-11-22T13: 07: 04Z "), "LastHeartbeat": ISODate ("2012-11-22T13: 57: 14Z "), "PingMs": 0 },                 { "_ Id": 3, "Name": "redhatB.example.com: 27021 ", "Health": 0, "State": 8, "StateStr": "(not reachable/healthy )", "Uptime": 0, "Optime": Timestamp (1353589624000, 1 ), "OptimeDate": ISODate ("2012-11-22T13: 07: 04Z "), "LastHeartbeat": ISODate ("2012-11-22T13: 55: 20Z "), "PingMs": 0, "Errmsg": "socket exception [CONNECT_ERROR] for redhatB.example.com: 27021"                 } ], "OK": 1 } Note: the status of the last node stateStr is not reachable/healthy ".   -- 4 delete a node Rs0: PRIMARY> rs. remove ("redhatB.example.com: 27021 "); Thu Nov 22 21:58:45 DBClientCursor: init call () failed Thu Nov 22 21:58:45 query failed: admin. $ cmd {replSetReconfig: {_ id: "rs0", version: 5, members: [{_ id: 0, host: "redhatB.example.com: 27018"}, {_ id: 1, host: "redhatB.example.com: 27019"}, {_ id: 2, host: "redhatB.example.com: 27020"}]} to: 127.0.0.1: 27018 Thu Nov 22 21:58:45 Error: error doing query: failed src/mongo/shell/collection. js: 155 Thu Nov 22 21:58:45 trying reconnect to 127.0.0.1: 27018 Thu Nov 22 21:58:45 reconnect 127.0.0.1: 27018 OK Rs0: SECONDARY> Rs0: PRIMARY>    -- 5 view the replica set configuration again Rs0: PRIMARY> rs. conf (); { "_ Id": "rs0 ", "Version": 5, "Members ":[                 { "_ Id": 0, "Host": "redhatB.example.com: 27018" },                 { "_ Id": 1, "Host": "redhatB.example.com: 27019" },                 { "_ Id": 2, "Host": "redhatB.example.com: 27020"                 }         ] }

   
Note: The node "redhatB.example.com: 27021" has been deleted.

-- 6 delete the data directory of the old node

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[Mongo @ redhatB mongodb] $ rm-rf/mongodb/data04