我正在参加「掘金·启航计划」

mongo故障模拟-权重调整

1.测试副本集是否是高可用

1.1.停掉mongodb-1:29017节点

[root@mongodb-1 /data1/mongodb_cluster]# ./mongodb/bin/mongod -f /data1/mongodb_cluster/mongodb_29017/conf/mongo_29017.conf --shutdown 
killing process with pid: 57659

查看是否可用查看，插入，删除

故障自动转移成功

1.2.开启mongodb-1:29017节点，查看是否转为primary

1.3.停掉mongodb-1:29018、mongodb-1:29017节点，查看29019节点是否成为primary

发现29019节点没有成为primary，其他节点也都是不正常的，这个架构就不可用了

[root@mongodb-1 /data1/mongodb_cluster]# ./mongodb/bin/mongo mongodb-1:29019
MongoDB shell version v4.0.14
connecting to: mongodb://mongodb-1:29019/test?gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("8332f408-753a-4008-bd83-d8283f324fcb") }
MongoDB server version: 4.0.14
Server has startup warnings:
2022-09-15T14:40:10.842+0800 I CONTROL  [initandlisten]
2022-09-15T14:40:10.842+0800 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
2022-09-15T14:40:10.842+0800 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
2022-09-15T14:40:10.842+0800 I CONTROL  [initandlisten] ** WARNING: You are running this process as the root user, which is not recommended.
2022-09-15T14:40:10.842+0800 I CONTROL  [initandlisten]
dba01:SECONDARY>
dba01:SECONDARY>
dba01:SECONDARY>
dba01:SECONDARY>
dba01:SECONDARY>
dba01:SECONDARY>
dba01:SECONDARY> rs.status();
{
        "set" : "dba01",
        "date" : ISODate("2022-09-15T06:41:10.443Z"),
        "myState" : 2,
        "term" : NumberLong(6),
        "syncingTo" : "",
        "syncSourceHost" : "",
        "syncSourceId" : -1,
        "heartbeatIntervalMillis" : NumberLong(2000),
        "optimes" : {
                "lastCommittedOpTime" : {
                        "ts" : Timestamp(0, 0),
                        "t" : NumberLong(-1)
                },
                "appliedOpTime" : {
                        "ts" : Timestamp(1663223977, 1),
                        "t" : NumberLong(5)
                },
                "durableOpTime" : {
                        "ts" : Timestamp(1663223977, 1),
                        "t" : NumberLong(5)
                }
        },
        "lastStableCheckpointTimestamp" : Timestamp(1663223977, 1),
        "members" : [
                {
                        "_id" : 0,
                        "name" : "mongodb-1:29017",
                        "health" : 0,
                        "state" : 8,
                        "stateStr" : "(not reachable/healthy)",
                        "uptime" : 0,
                        "optime" : {
                                "ts" : Timestamp(0, 0),
                                "t" : NumberLong(-1)
                        },
                        "optimeDurable" : {
                                "ts" : Timestamp(0, 0),
                                "t" : NumberLong(-1)
                        },
                        "optimeDate" : ISODate("1970-01-01T00:00:00Z"),
                        "optimeDurableDate" : ISODate("1970-01-01T00:00:00Z"),
                        "lastHeartbeat" : ISODate("2022-09-15T06:41:09.681Z"),
                        "lastHeartbeatRecv" : ISODate("1970-01-01T00:00:00Z"),
                        "pingMs" : NumberLong(0),
                        "lastHeartbeatMessage" : "Error connecting to mongodb-1:29017 (192.168.146.138:29017) :: caused by :: Connection refused",
                        "syncingTo" : "",
                        "syncSourceHost" : "",
                        "syncSourceId" : -1,
                        "infoMessage" : "",
                        "configVersion" : -1
                },
                {
                        "_id" : 1,
                        "name" : "mongodb-1:29018",
                        "health" : 0,
                        "state" : 8,
                        "stateStr" : "(not reachable/healthy)",
                        "uptime" : 0,
                        "optime" : {
                                "ts" : Timestamp(0, 0),
                                "t" : NumberLong(-1)
                        },
                        "optimeDurable" : {
                                "ts" : Timestamp(0, 0),
                                "t" : NumberLong(-1)
                        },
                        "optimeDate" : ISODate("1970-01-01T00:00:00Z"),
                        "optimeDurableDate" : ISODate("1970-01-01T00:00:00Z"),
                        "lastHeartbeat" : ISODate("2022-09-15T06:41:10.388Z"),
                        "lastHeartbeatRecv" : ISODate("2022-09-15T06:41:07.764Z"),
                        "pingMs" : NumberLong(0),
                        "lastHeartbeatMessage" : "Error connecting to mongodb-1:29018 (192.168.146.138:29018) :: caused by :: Connection refused",
                        "syncingTo" : "",
                        "syncSourceHost" : "",
                        "syncSourceId" : -1,
                        "infoMessage" : "",
                        "configVersion" : -1
                },
                {
                        "_id" : 2,
                        "name" : "mongodb-1:29019",
                        "health" : 1,
                        "state" : 2,
                        "stateStr" : "SECONDARY",
                        "uptime" : 60,
                        "optime" : {
                                "ts" : Timestamp(1663223977, 1),
                                "t" : NumberLong(5)
                        },
                        "optimeDate" : ISODate("2022-09-15T06:39:37Z"),
                        "syncingTo" : "",
                        "syncSourceHost" : "",
                        "syncSourceId" : -1,
                        "infoMessage" : "could not find member to sync from",
                        "configVersion" : 1,
                        "self" : true,
                        "lastHeartbeatMessage" : ""
                }
        ],
        "ok" : 1,
        "operationTime" : Timestamp(1663223977, 1),
        "$clusterTime" : {
                "clusterTime" : Timestamp(1663223977, 1),
                "signature" : {
                        "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
                        "keyId" : NumberLong(0)
                }
        }
}
dba01:SECONDARY>

1.3.1.修复这个故障

1.启动29018
[root@mongodb-1 /data1/mongodb_cluster]# ./mongodb/bin/mongod -f /data1/mongodb_cluster/mongodb_29018/conf/mongo_29018.conf
about to fork child process, waiting until server is ready for connections.
forked process: 103563
child process started successfully, parent exiting

2.登录29019
[root@mongodb-1 /data1/mongodb_cluster]# ./mongodb/bin/mongo mongodb-1:29019

2.权重调整

2.1.查看集群配置信息

[root@mongodb-1 /data1/mongodb_cluster]# ./mongodb/bin/mongo mongodb-1:29017 
dba01:PRIMARY> rs.conf() 
#目前权重都是一样的

2.2.调整权重,将29019调为primary

[root@mongodb-1 /data1/mongodb_cluster]# ./mongodb/bin/mongo mongodb-1:29017
dba01:PRIMARY> config = rs.conf()
dba01:PRIMARY> config.members[2].priority=100
100
dba01:PRIMARY> rs.reconfig(config)
{
        "ok" : 1,
        "operationTime" : Timestamp(1663227028, 1),
        "$clusterTime" : {
                "clusterTime" : Timestamp(1663227028, 1),
                "signature" : {
                        "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
                        "keyId" : NumberLong(0)
                }
        }
}
dba01:PRIMARY> rs.conf()

解释说明：
config = rs.conf()  导入数据
config.members[2].priority=100：将[2]也就是29019节点的权重调整为100；如果想把29018调整为primary,将2改为1---config.members[1].priority=100
rs.reconfig(config)   重新加载生效

查看已变为secondary节点

2.3.调低权重,重新选举

dba01:PRIMARY> rs.stepDown()