mongodb副本集(PSA模式)修改节点信息(priority和votes)

环境:
OS:Centos7
mongodb:4.4.22

 

我们在副本集扩容的情况下,新加入节点一般设置priority和votes都为0,待新节点数据同步完成后再进行修改:
主库上执行新增新的节点:
myrepl:PRIMARY>rs.add({ host: "192.168.1.107:29001", priority: 0, votes: 0 })
待同步完成后查看副本集配置

 

myrepl:PRIMARY> rs.config()
{
        "_id" : "myrepl",
        "version" : 23819,
        "protocolVersion" : NumberLong(1),
        "writeConcernMajorityJournalDefault" : true,
        "members" : [
                {
                        "_id" : 0,
                        "host" : "192.168.1.102:29001",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 1,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                },
                {
                        "_id" : 3,
                        "host" : "192.168.1.105:29001",
                        "arbiterOnly" : true,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 0,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                },
                {
                        "_id" : 4,
                        "host" : "192.168.1.107:29001",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 0,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 0
                }
        ],
        "settings" : {
                "chainingAllowed" : true,
                "heartbeatIntervalMillis" : 2000,
                "heartbeatTimeoutSecs" : 10,
                "electionTimeoutMillis" : 10000,
                "catchUpTimeoutMillis" : -1,
                "catchUpTakeoverDelayMillis" : 30000,
                "getLastErrorModes" : {

                },
                "getLastErrorDefaults" : {
                        "w" : 1,
                        "wtimeout" : 0
                },
                "replicaSetId" : ObjectId("64b0a3f881b811c4931d4d4c")
        }
}

 

可以看到id=4的节点,priority和votes都为0,下面进行修改
members的下标数字对对应数组的序号(这里是0,1,2),我们这里是要修改数组序号为2的member

myrepl:PRIMARY>var cfg = rs.conf()
myrepl:PRIMARY>cfg.members[2].priority = 1
myrepl:PRIMARY>cfg.members[2].votes = 1
myrepl:PRIMARY> rs.reconfig(cfg)
{
        "ok" : 0,
        "errmsg" : "Rejecting reconfig where the new config has a PSA topology and the secondary is electable, but the old config contains only one writable node. Refer to https://docs.mongodb.com/manual/reference/method/rs.reconfigForPSASet/ for next steps on reconfiguring a PSA set.",
        "code" : 103,
        "codeName" : "NewReplicaSetConfigurationIncompatible"
}

这里报错误了,提示说明psa拓扑不能使用这种方式修改,尝试使用如下方式修改

 

myrepl:PRIMARY>cfg = rs.conf();
myrepl:PRIMARY>cfg["members"] = 
[
                {
                        "_id" : 0,
                        "host" : "192.168.1.102:29001",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 1,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                },
                {
                        "_id" : 3,
                        "host" : "192.168.1.105:29001",
                        "arbiterOnly" : true,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 0,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                },
                {
                        "_id" : 4,
                        "host" : "192.168.1.107:29001",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 1,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                }
]

myrepl:PRIMARY> rs.reconfigForPSASet(2, cfg);
Running first reconfig to give member at index 2 { votes: 1, priority: 0 }
Running second reconfig to give member at index 2 { priority: 1 }
{ "ok" : 1 }

 

rs.reconfigForPSASet( memberIndex, config, { options } )的使用方法

memberIndex为member数组的序号

 

查看新配置

myrepl:PRIMARY> rs.conf()
{
        "_id" : "myrepl",
        "version" : 23821,
        "protocolVersion" : NumberLong(1),
        "writeConcernMajorityJournalDefault" : true,
        "members" : [
                {
                        "_id" : 0,
                        "host" : "192.168.1.102:29001",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 1,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                },
                {
                        "_id" : 3,
                        "host" : "192.168.1.105:29001",
                        "arbiterOnly" : true,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 0,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                },
                {
                        "_id" : 4,
                        "host" : "192.168.1.107:29001",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 1,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                }
        ],
        "settings" : {
                "chainingAllowed" : true,
                "heartbeatIntervalMillis" : 2000,
                "heartbeatTimeoutSecs" : 10,
                "electionTimeoutMillis" : 10000,
                "catchUpTimeoutMillis" : -1,
                "catchUpTakeoverDelayMillis" : 30000,
                "getLastErrorModes" : {

                },
                "getLastErrorDefaults" : {
                        "w" : 1,
                        "wtimeout" : 0
                },
                "replicaSetId" : ObjectId("64b0a3f881b811c4931d4d4c")
        }
}