该文档默认命名和配置：
- 复制集名称为：ulocation
- 三台mongo实例，192.168.50.222（primary，第一台），192.168.50.223（secondary，第二胎），192.168.50.223（arbiter，第三台）
- mongo数据目录：/var/lib/mongo/，日志目录/var/log/mongodb/,备份目录：/app/mongo/backup,keyfile文件：/app/mongo/mongo.keyfile
mongo centos安装卸载
注： 如下操作是在ip、防火墙、selinux都配置好后进行的。
1.配置yum源
vim /etc/yum.repos.d/mongodb-enterprise.repo
[mongodb-enterprise]
name=MongoDB Enterprise Repository
baseurl=https://repo.mongodb.com/yum/redhat/$releasever/mongodb-enterprise/4.0/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-4.0.asc
2.yum安装
yum install -y mongodb-enterprise-4.0.6 mongodb-enterprise-server-4.0.6 mongodb-enterprise-shell-4.0.6 mongodb-enterprise-mongos-4.0.6 mongodb-enterprise-tools-4.0.6
3.防止yum update更新
vim /etc/yum.conf
exclude=mongodb-enterprise,mongodb-enterprise-server,mongodb-enterprise-shell,mongodb-enterprise-mongos,mongodb-enterprise-tools
4.常用命令
sudo service mongod start
sudo chkconfig mongod on
sudo service mongod stop
sudo service mongod restart
5.mongo centos移除
sudo service mongod stop
sudo yum erase $(rpm -qa | grep mongodb-enterprise)
sudo rm -r /var/log/mongodb
sudo rm -r /var/lib/mongo
以上5部骤参考：https://docs.mongodb.com/manual/tutorial/install-mongodb-enterprise-on-red-hat/
6.Percona Server for MongoDB 4.0 安装
yum install https://repo.percona.com/yum/percona-release-latest.noarch.rpm
percona-release enable psmdb-40 release
yum install percona-server-mongodb
service mongod start
chkconfig mongod on
service mongod stop
mongo开启身份认证（复制集环境）
https://docs.mongodb.com/manual/tutorial/enable-authentication/
创建keyfile
mkdir -p /app/mongo
openssl rand -base64 756 > /app/mongo/mongo.keyfile
chmod 400 /app/mongo/mongo.keyfile
chown mongod:mongod /app/mongo/mongo.keyfile�
创建超级管理员
mongo
use admin
db.createUser(
{
user: "admin",
pwd: "admin@13579*01",
roles: [ { role: "userAdminAnyDatabase", db: "admin" }, { "role" : "clusterAdmin", "db" : "admin" }, "readWriteAnyDatabase","root" ]
}
)
创建ulocation管理员
use ulocation
db.createUser(
{
user: "ulocation",
pwd: "ulocation2019",
roles: [ { role: "readWrite", db: "ulocation" }]
}
)
若为复制集，需将keyfile拷贝到其他节点上。
关闭mongo实例，修改配置文件：
security:
authorization: enabled
keyFile: /app/mongo/mongo.keyfile�
使用创建的用户登录
mongo --port 27017 -u "admin" --authenticationDatabase "admin" -p
mongo --port 27017 -u "ulocation" --authenticationDatabase "ulocation" -p
--authenticationDatabase : 指定用户在哪个库中创建，若不指定，mongo使用连接串中的数据库。
Standalone mongo实例转为复制集
1.关闭第一台实例
mongo
use admin
db.shutdownServer()
2.第一台实例增加复制集启动配置项，并启动
vim /etc/mongod.conf
replication:
replSetName: ulocation
enableMajorityReadConcern: false # PSA架构需关闭此项
service mongod start
3.第一台实例配置复制集信息
mongo
config = {
"_id":"ulocation",
"members":[
{"_id":0,"host":"192.168.50.222:27017"},
]
}
rs.initiate(config)
该节点为primary节点
4.新增secondary mongo
在第二台mongo实例，操作1、2两部
在primary上执行：
rs.add( { host: "192.168.50.223:27017", priority: 0, votes: 0 } )
调用该命令后，会自动执行Initial Sync，进行数据同步
修改priority和vote（原因：When a newly added secondary has its votes and priority settings greater than zero, during its initial sync, the secondary still counts as a voting member even though it cannot serve reads nor become primary because its data is not yet consistent.）
var cfg = rs.conf();
cfg.members[1].priority = 1
cfg.members[1].votes = 1
rs.reconfig(cfg)
5.新增仲裁成员
在第三台mongo实例，操作1、2两部
在primary上执行：
rs.addArb("192.168.50.224:27017")
参考：https://docs.mongodb.com/manual/tutorial/convert-standalone-to-replica-set/
https://docs.mongodb.com/manual/tutorial/expand-replica-set/
https://docs.mongodb.com/manual/tutorial/add-replica-set-arbiter/
Initial Sync数据同步
两种方式：
方式一：在primary上执行：rs.add( { host: "192.168.50.223:27017", priority: 0, votes: 0 } )。注：前提是空的数据目录
方式二：拷贝primary上的数据文件，步骤如下：
1.停掉primary，拷贝数据文件
2.停掉secondary将拷贝的数据文件移到secondary的数据目录
3.rm -rf mongod.lock（不删除会报“Attempted to create a lock file on a read-only directory: /var/lib/mongo”）
chown -R mongod:mongod *
4.启动secondary上的mongo实例
Percona Server热备份
mkdir -p /app/mongo/backup
chown -R mongod:mongod /app/mongo/backup
> use admin
switched to db admin
> db.runCommand({createBackup: 1, backupDir: "/app/mongo/backup"})
{ "ok" : 1 }
mongo shell常用语句
库操作：
show dbs;
use test;
test.dropDatabase();
查询语句：
日期：ISODate("2012-12-19T06:01:17.171Z")
db.inventory.find( {} )
db.inventory.find( { status: "D" } )
db.inventory.find( { status: { $in: [ "A", "D" ] } } )
db.inventory.find( { status: "A", qty: { $lt: 30 } } )
db.inventory.find( { $or: [ { status: "A" }, { qty: { $lt: 30 } } ] } )
赋角色：
db.grantRolesToUser(
"dayunAdmin",
[
{ role: "root", db: "admin" }
]
)
复制集
rs.conf()
rs.status()
db.printReplicationInfo()
rs.printSlaveReplicationInfo()
FAQ
-
(PSA) architecture关闭enableMajorityReadConcern
Read Concern "majority": https://docs.mongodb.com/manual/reference/read-concern-majority/#disable-read-concern-majority
-
主节点db.shutdownServer(),会出现失败
ulocation:PRIMARY> db.shutdownServer() 2019-04-17T12:34:12.606+0800 E QUERY [js] Error: shutdownServer failed: { "operationTime" : Timestamp(1555475638, 1), "ok" : 0, "errmsg" : "No electable secondaries caught up as of 2019-04-17T12:34:12.604+0800Please use the replSetStepDown command with the argument {force: true} to force node to step down.", "code" : 262, "codeName" : "ExceededTimeLimit", "$clusterTime" : { "clusterTime" : Timestamp(1555475638, 1), "signature" : { "hash" : BinData(0,"dHvSJ4hy78YRfqf0hSAotb29wuo="), "keyId" : NumberLong("6680450114256896002") } } } :解决：先降级，db.adminCommand( { replSetStepDown: 120, secondaryCatchUpPeriodSecs: 15, force: true } )，然后，关闭。
-
先正常运行，修改配置后运行不成功，还原回去后还不能正常运行
删除 /tmp/mongodb-27017.sock
