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freedev
Asked: 2013-03-27 17:17:06 +0800 CST

remove a mongodb replica set when into a sharding cluster

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I have this configuration:

mongos> db.adminCommand('getShardMap')
{
"map" : {
    "RS13" : "RS13/mongo09-02:27003,mongo09-01:27001",
    "RS13/mongo09-02:27003,mongo09-01:27001" : "RS13/mongo09-02:27003,mongo09-01:27001",
    "RS26" : "RS26/mongo09-04.de.prod:27008,mongo09-01:27002",
    "RS26/mongo09-04.de.prod:27008,mongo09-01:27002" : "RS26/mongo09-04.de.prod:27008,mongo09-01:27002",
    "RS45" : "RS45/mongo09-02:27004,mongo09-03:27005",
    "RS45/mongo09-02:27004,mongo09-03:27005" : "RS45/mongo09-02:27004,mongo09-03:27005",
    "RS67" : "RS67/mongo09-03:27006,mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",
    "RS67/mongo09-03:27006,mongo09-03.de.prod:27006,mongo09-04.de.prod:27007" : "RS67/mongo09-03:27006,mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",
    "config" : "mongo09-01:27011,mongo09-02:27012,mongo09-03:27013",
    "mongo09-01:27001" : "RS13/mongo09-02:27003,mongo09-01:27001",
    "mongo09-01:27002" : "RS26/mongo09-04.de.prod:27008,mongo09-01:27002",
    "mongo09-02:27003" : "RS13/mongo09-02:27003,mongo09-01:27001",
    "mongo09-02:27004" : "RS45/mongo09-02:27004,mongo09-03:27005",
    "mongo09-03.de.prod:27006" : "RS67/mongo09-03:27006,mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",
    "mongo09-03:27005" : "RS45/mongo09-02:27004,mongo09-03:27005",
    "mongo09-03:27006" : "RS67/mongo09-03:27006,mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",
    "mongo09-04.de.prod:27007" : "RS67/mongo09-03:27006,mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",
    "mongo09-04.de.prod:27008" : "RS26/mongo09-04.de.prod:27008,mongo09-01:27002"
},
"ok" : 1
}

Actually mongo09-03 it seems to be duplicated:

    "mongo09-03.de.prod:27006" : "RS67/mongo09-03:27006,mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",
    "mongo09-03:27006" : "RS67/mongo09-03:27006,mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",

And please consider replica set RS67 is also part of a sharding cluster.

May I remove a mongodb replica set when it is into a sharding cluster ? And if yes, how?

Can I use rs.remove(hostname) ?

cluster

2 Answers

  1. It isn't an easy run one command type thing. See the following on the doc site

    http://docs.mongodb.org/manual/tutorial/remove-shards-from-cluster/

    To remove a replicaset member

     rs.remove("mongo09-03.de.prod:27006")
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  2. We have successfully configured the replica set executing this command:

    db.shards.update({_id: "RS67"} , {$set: {"host" : "RS67/mongo09-03.de.prod:27006,mongo09-04.de.prod:27007"}})

    The shard map now it is correctly configured and extra mongo09-03 has been disappeared.

    mongos> db.adminCommand('getShardMap') 
{
"map" : {
    "RS13" : "RS13/mongo09-02:27003,mongo09-01:27001",
    "RS13/mongo09-02:27003,mongo09-01:27001" : "RS13/mongo09-02:27003,mongo09-01:27001",
    "RS26" : "RS26/mongo09-04.de.prod:27008,mongo09-01:27002",
    "RS26/mongo09-04.de.prod:27008,mongo09-01:27002" : "RS26/mongo09-04.de.prod:27008,mongo09-01:27002",
    "RS45" : "RS45/mongo09-02:27004,mongo09-03:27005",
    "RS45/mongo09-02:27004,mongo09-03:27005" : "RS45/mongo09-02:27004,mongo09-03:27005",
    "RS67" : "RS67/mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",
    "RS67/mongo09-03.de.prod:27006,mongo09-04.de.prod:27007" : "RS67/mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",
    "config" : "mongo09-01:27011,mongo09-02:27012,mongo09-03:27013",
    "mongo09-01:27001" : "RS13/mongo09-02:27003,mongo09-01:27001",
    "mongo09-01:27002" : "RS26/mongo09-04.de.prod:27008,mongo09-01:27002",
    "mongo09-02:27003" : "RS13/mongo09-02:27003,mongo09-01:27001",
    "mongo09-02:27004" : "RS45/mongo09-02:27004,mongo09-03:27005",
    "mongo09-03.de.prod:27006" : "RS67/mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",
    "mongo09-03:27005" : "RS45/mongo09-02:27004,mongo09-03:27005",
    "mongo09-04.de.prod:27007" : "RS67/mongo09-03.de.prod:27006,mongo09-04.de.prod:27007",
    "mongo09-04.de.prod:27008" : "RS26/mongo09-04.de.prod:27008,mongo09-01:27002"
},
"ok" : 1
}

    please also consider that:

    The list of hosts in the collection is only used when mongos first starts up, as a seed list. Once the process starts they auto-discover the rest of the members (just like any other client/driver in replica set mode) and keep track of each member in the replica set.

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