MongoDB副本集如何添加和删除仲裁节点

2024-04-02 19:55

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小编给大家分享一下MongoDB副本集如何添加和删除仲裁节点，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！

MongoDB仲裁者（Arbiter）是复制集中的一个mongodb实例，它并不保存数据。
仲裁节点使用最小的资源并且不要求硬件设备，最好不要将Arbiter部署在同一个数据集节点中，可以部署在其他服务器中，也可部署在单独的虚拟机中。

当节点数目为奇数时，可以不需要仲裁节点。
当节点数目为偶数个时，需要部署一个仲裁节点，否则偶数个节点，当主节点挂了后，其他节点会变为只读。

副本集添加仲裁节点步骤(本例中MongoDB副本集是一主两从):
添加仲裁节点:
在仲裁节点编辑mongodb.conf
# vi /etc/mongodb.conf
logpath=/home/mongodb/logs/arbiter.log
logappend=false
port=27019
fork=true
dbpath=/home/mongodb/arbiter
#auth=true
replSet=test (应和副本集其他节点的集群名字保持一致)

启动arbiter上的mongodb实例:
#/data/mongodb-3.4.13/bin/mongod -f /etc/mongodb.conf
about to fork child process, waiting until server is ready for connections.
forked process: 23331
child process started successfully, parent exiting

登陆到副本集上的主节点，进行如下操作:
test:PRIMARY> rs.addArb("192.168.0.3:27019");
{ "ok" : 1 }

查看状态:
test:PRIMARY> rs.status()
{
        "set" : "test",
        "date" : ISODate("2018-02-27T08:24:28.866Z"),
        "myState" : 1,
        "term" : NumberLong(6),
        "heartbeatIntervalMillis" : NumberLong(2000),
        "optimes" : {
                "lastCommittedOpTime" : {
                        "ts" : Timestamp(1519719858, 1),
                        "t" : NumberLong(6)
                },
                "appliedOpTime" : {
                        "ts" : Timestamp(1519719858, 1),
                        "t" : NumberLong(6)
                },
                "durableOpTime" : {
                        "ts" : Timestamp(1519719858, 1),
                        "t" : NumberLong(6)
                }
        },
        "members" : [
                {
                        "_id" : 0,
                        "name" : "192.168.0.51:27017",
                        "health" : 1,
                        "state" : 1,
                        "stateStr" : "PRIMARY",
                        "uptime" : 4429,
                        "optime" : {
                                "ts" : Timestamp(1519719858, 1),
                                "t" : NumberLong(6)
                        },
                        "optimeDate" : ISODate("2018-02-27T08:24:18Z"),
                        "electionTime" : Timestamp(1519716787, 1),
                        "electionDate" : ISODate("2018-02-27T07:33:07Z"),
                        "configVersion" : 4,
                        "self" : true
                },
                {
                        "_id" : 1,
                        "name" : "192.168.0.52:27017",
                        "health" : 1,
                        "state" : 2,
                        "stateStr" : "SECONDARY",
                        "uptime" : 4369,
                        "optime" : {
                                "ts" : Timestamp(1519719858, 1),
                                "t" : NumberLong(6)
                        },
                        "optimeDurable" : {
                                "ts" : Timestamp(1519719858, 1),
                                "t" : NumberLong(6)
                        },
                        "optimeDate" : ISODate("2018-02-27T08:24:18Z"),
                        "optimeDurableDate" : ISODate("2018-02-27T08:24:18Z"),
                        "lastHeartbeat" : ISODate("2018-02-27T08:24:27.265Z"),
                        "lastHeartbeatRecv" : ISODate("2018-02-27T08:24:28.224Z"),
                        "pingMs" : NumberLong(0),
                        "syncingTo" : "192.168.0.51:27017",
                        "configVersion" : 4
                },
                {
                        "_id" : 2,
                        "name" : "192.168.0.61:27017",
                        "health" : 1,
                        "state" : 2,
                        "stateStr" : "SECONDARY",
                        "uptime" : 2501,
                        "optime" : {
                                "ts" : Timestamp(1519719858, 1),
                                "t" : NumberLong(6)
                        },
                        "optimeDurable" : {
                                "ts" : Timestamp(1519719858, 1),
                                "t" : NumberLong(6)
                        },
                        "optimeDate" : ISODate("2018-02-27T08:24:18Z"),
                        "optimeDurableDate" : ISODate("2018-02-27T08:24:18Z"),
                        "lastHeartbeat" : ISODate("2018-02-27T08:24:27.099Z"),
                        "lastHeartbeatRecv" : ISODate("2018-02-27T08:24:28.024Z"),
                        "pingMs" : NumberLong(0),
                        "syncingTo" : "192.168.0.51:27017",
                        "configVersion" : 4
                },
                {
                        "_id" : 3,
                        "name" : "192.168.0.3:27019",
                        "health" : 1,
                        "state" : 7,
                        "stateStr" : "ARBITER",
                        "uptime" : 96,
                        "lastHeartbeat" : ISODate("2018-02-27T08:24:28.443Z"),
                        "lastHeartbeatRecv" : ISODate("2018-02-27T08:24:27.449Z"),
                        "pingMs" : NumberLong(1),
                        "configVersion" : 4
                }
        ],
        "ok" : 1
}
test:PRIMARY>

test:PRIMARY> db.isMaster()
{
        "hosts" : [
                "192.168.0.51:27017",
                "192.168.0.52:27017",
                "192.168.0.61:27017"
        ],
        "arbiters" : [
                "192.168.0.3:27019"
        ],
        "setName" : "test",
        "setVersion" : 4,
        "ismaster" : true,
        "secondary" : false,
        "primary" : "192.168.0.51:27017",
        "me" : "192.168.0.51:27017",
        "electionId" : ObjectId("7fffffff0000000000000006"),
        "lastWrite" : {
                "opTime" : {
                        "ts" : Timestamp(1519719928, 1),
                        "t" : NumberLong(6)
                },
                "lastWriteDate" : ISODate("2018-02-27T08:25:28Z")
        },
        "maxBsonObjectSize" : 16777216,
        "maxMessageSizeBytes" : 48000000,
        "maxWriteBatchSize" : 1000,
        "localTime" : ISODate("2018-02-27T08:25:33.660Z"),
        "maxWireVersion" : 5,
        "minWireVersion" : 0,
        "readOnly" : false,
        "ok" : 1
}

删除仲裁节点方法:
test:PRIMARY> rs.remove("192.168.0.3:27019");