mongodb副本集，执行 rs.addArb(“172.18.30.110:27019”) 或者rs.add(“172.18.30.110:27019”, true) 添加仲裁节点，客户端卡住，半天没有反应，解决方法

1、可以退出主节点后，重新登录，

# Ctrl + C 或者： exit 退出主节点
myrs:PRIMARY> exit
bye

# 重新登录客户端
root@WIN-20240529BJA:/usr/local/mongodb# ./mongodb-linux-x86_64-ubuntu1804-5.0.28/bin/mongo --host=172.18.30.110 --port=27017

2、执行 以下 命令

myrs:PRIMARY>  db.adminCommand({"setDefaultRWConcern" : 1,"defaultWriteConcern" : {"w" : 2}}) 

3、再次执行添加仲裁节点命令

myrs:PRIMARY>  rs.addArb("172.18.30.110:27019")：

4、演示：

myrs:PRIMARY> db.adminCommand({"setDefaultRWConcern" : 1,"defaultWriteConcern" : {"w" : 2}})
{
        "defaultReadConcern" : {
                "level" : "local"
        },
        "defaultWriteConcern" : {
                "w" : 2,
                "wtimeout" : 0
        },
        "updateOpTime" : Timestamp(1722423661, 1),
        "updateWallClockTime" : ISODate("2024-07-31T11:01:02.859Z"),
        "defaultWriteConcernSource" : "global",
        "defaultReadConcernSource" : "implicit",
        "localUpdateWallClockTime" : ISODate("2024-07-31T11:01:03.141Z"),
        "ok" : 1,
        "$clusterTime" : {
                "clusterTime" : Timestamp(1722423663, 1),
                "signature" : {
                        "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
                        "keyId" : NumberLong(0)
                }
        },
        "operationTime" : Timestamp(1722423663, 1)
}
myrs:PRIMARY> 
myrs:PRIMARY> 
myrs:PRIMARY> rs.addArb("172.18.30.110:27019")
{
        "ok" : 1,
        "$clusterTime" : {
                "clusterTime" : Timestamp(1722423719, 1),
                "signature" : {
                        "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
                        "keyId" : NumberLong(0)
                }
        },
        "operationTime" : Timestamp(1722423719, 1)
}
myrs:PRIMARY>