MongoDB集群部署 - 带访问控制的分片副本集

1. 前言

  Ceilometer将meter、event等数据保存在MongoDB中,之前将MongoDB部署在控制节点上,使用三副本模式,时间长了发现meter数据爆炸式增长,区区2T的磁盘捉襟见肘,而想删除旧数据,需要执行db.repairDatabase()命令才能真正回收磁盘空间。

  虽然按官方说法,MongoDB 3.2版本以后默认使用的WiredTiger Storage Engine,在执行db.repairDatabase()时不需要额外空间,可实际操作时发现它会重建索引,保存在storage.dbPath/_tmp目录下,剩余的200GB容量完全不够用来创建1.7TB数据的索引,容量用完,进程就卡住了。本机上又没有空闲的磁盘用来补充容量,这个节点上的MongoDB服务基本算是废了。

  幸好Ceilometer不是核心服务,大不了把数据全删了重来。但是考虑到它的数据量太大,很有可能会影响到控制节点的性能,还是把MongoDB单独拎出来部署更为保险。搜了一圈,发现目前MongoDB集群的部署方案都是分片+副本集,我在这之上补充了权限验证的配置步骤,整理成这篇文档。

 

2. 环境

使用了三台服务器,部署三个分片,每个分片三副本。实际上分片数量可以是任意个,试主机性能而定。各个分片之间是完全相互独立的,一个database的数据只会落在一个分片上。

服务器:10.212.36.38、10.212.36.39、10.212.36.40

系统:CentOS Linux release 7.2.1511 (Core)

MongoDB:v4.0.0

部署结构如下表所示:

10.212.36.38

10.212.36.39

10.212.36.40

mongos: 27017

mongos: 27017

mongos: 27017

config: 27018

config: 27018

config: 27018

shard01: 27101

shard01: 27101

shard01: 27101

shard02: 27102

shard02: 27102

shard02: 27102

shard03: 27103

shard03: 27103

shard03: 27103

mongos是对外提供服务的进程,本身不保存数据,而是将请求转发到分片;config保存集群配置数据;shard是实际存储数据的服务,每个shard相互独立,由mongos调度。

 

3. 安装MongoDB

3.1 添加yum源

cat > /etc/yum.repos.d/mongodb-org-4.0.repo << EOF
[mongodb-org-4.0]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/4.0/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-4.0.asc
EOF

3.2 安装

# yum -y install mongodb-org

3.3 删除mongod服务

由于不是通过软件包内置的服务启动mongod进程,删除mongod这个服务避免误启动,也可以保留服务文件作为参照。

# systemctl disable mongod
# rm –f /usr/lib/systemd/system/mongod.service
# systemctl daemon-reload

 

4. 部署高可用MongoDB集群

4.1 准备配置文件

每台服务器上都运行monogs、config、shard01、shard02、shard03服务,分别对应一个配置文件,统一将配置文件存放在/etc/mongodb/目录下。

# mkdir /etc/mongodb/
# chown –R mongod:mongod /etc/mongodb/

将config和shard的数据保存在/data/mongodb/目录下。

# mkdir -p /data/mongodb/{config,shard01,shard02,shard03}/data /data/mongodb/mongos
# chown –R mongod:mongod /data/mongodb/

日志统一存放在/var/log/mongodb/目录下。

# mkdir /var/log/mongodb
# chown –R mongod:mongod /var/log/mongodb/

/etc/mongodb/shard01.conf

# where to write logging data.
systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/shard01.log

# Where and how to store data.
storage:
  dbPath: /data/mongodb/shard01/data
  journal:
    enabled: true
  wiredTiger:
    engineConfig:
       cacheSizeGB: 20

# how the process runs
processManagement:
  fork: true
  pidFilePath: /data/mongodb/shard01/mongodb-shard01.pid
  timeZoneInfo: /usr/share/zoneinfo

# network interfaces
net:
  port: 27101
  bindIp: 0.0.0.0
  unixDomainSocket:
    pathPrefix: /var/run/mongodb

#operationProfiling:
replication:
    replSetName: ussmongo-shard01

sharding:
    clusterRole: shardsvr
View Code

/etc/mongodb/shard02.conf

# where to write logging data.
systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/shard02.log

# Where and how to store data.
storage:
  dbPath: /data/mongodb/shard02/data
  journal:
    enabled: true
  wiredTiger:
    engineConfig:
       cacheSizeGB: 20

# how the process runs
processManagement:
  fork: true
  pidFilePath: /data/mongodb/shard02/mongodb-shard02.pid
  timeZoneInfo: /usr/share/zoneinfo

# network interfaces
net:
  port: 27102
  bindIp: 0.0.0.0
  unixDomainSocket:
    pathPrefix: /var/run/mongodb

#operationProfiling:
replication:
    replSetName: ussmongo-shard02

sharding:
    clusterRole: shardsvr
View Code

/etc/mongodb/shard03.conf

# where to write logging data.
systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/shard03.log

# Where and how to store data.
storage:
  dbPath: /data/mongodb/shard03/data
  journal:
    enabled: true
  wiredTiger:
    engineConfig:
       cacheSizeGB: 20

# how the process runs
processManagement:
  fork: true
  pidFilePath: /data/mongodb/shard03/mongodb-shard03.pid
  timeZoneInfo: /usr/share/zoneinfo

# network interfaces
net:
  port: 27103
  bindIp: 0.0.0.0
  unixDomainSocket:
    pathPrefix: /var/run/mongodb

#operationProfiling:
replication:
    replSetName: ussmongo-shard03

sharding:
    clusterRole: shardsvr
View Code

/etc/mongodb/config.conf

# where to write logging data.
systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/config.log

# Where and how to store data.
storage:
  dbPath: /data/mongodb/config/data
  journal:
    enabled: true

# how the process runs
processManagement:
  fork: true
  pidFilePath: /data/mongodb/config/mongodb-config.pid
  timeZoneInfo: /usr/share/zoneinfo

# network interfaces
net:
  port: 27018
  bindIp: 0.0.0.0
  unixDomainSocket:
    pathPrefix: /var/run/mongodb

#operationProfiling:
replication:
    replSetName: ussmongo-config

sharding:
    clusterRole: configsvr
View Code

/etc/mongodb/mongos.conf

systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/mongos.log

processManagement:
  fork: true
#  pidFilePath: /data/mongodb/mongos.pid

# network interfaces
net:
  port: 27017
  bindIp: 0.0.0.0
  unixDomainSocket:
    pathPrefix: /var/run/mongodb

sharding:
   configDB: ussmongo-config/10.212.36.38:27018,10.212.36.39:27018,10.212.36.40:27018

setParameter:
  diagnosticDataCollectionDirectoryPath: /data/mongodb/mongos/diagnostic.data/
View Code

4.2 准备服务文件

使用下面的命令可以启动MongoDB进程:

# mongod --quiet -f /etc/mongodb/shard01.conf

但是每个节点上都要启动五个进程,相当麻烦,也不便于后续维护。为了一劳永逸,以服务的方式运行MongoDB,使用systemctl管理MongoDB服务。

/usr/lib/systemd/system/mongo-shard@.service

[Unit]
Description=MongoDB Database Shard Service
After=network.target
Documentation=https://docs.mongodb.org/manual
PartOf=mongo-shard.target

[Service]
User=mongod
Group=mongod
Environment="OPTIONS=--quiet -f /etc/mongodb/shard%i.conf"
EnvironmentFile=-/etc/sysconfig/mongod
ExecStart=/usr/bin/mongod $OPTIONS
PermissionsStartOnly=true
Type=forking
TasksMax=infinity
TasksAccounting=false

[Install]
WantedBy=mongo-shard.target

/usr/lib/systemd/system/mongo-config.service

[Unit]
Description=MongoDB Database Config Service
After=network.target
Documentation=https://docs.mongodb.org/manual
PartOf=mongo.target

[Service]
User=mongod
Group=mongod
Environment="OPTIONS=--quiet -f /etc/mongodb/config.conf"
EnvironmentFile=-/etc/sysconfig/mongod
ExecStart=/usr/bin/mongod $OPTIONS
PermissionsStartOnly=true
Type=forking
TasksMax=infinity
TasksAccounting=false

[Install]
WantedBy=mongo.target

/usr/lib/systemd/system/mongos.service

[Unit]
Description=MongoDB Database Service
After=syslog.target network.target
PartOf=mongo.target

[Service]
User=mongod
Group=mongod
Environment="OPTIONS=--quiet -f /etc/mongodb/mongos.conf"
ExecStart=/usr/bin/mongos $OPTIONS
Type=forking
PrivateTmp=true
LimitNOFILE=64000
TimeoutStartSec=180

[Install]
WantedBy=mongo.target

为了便于批量管理,创建target文件:

/usr/lib/systemd/system/mongo-shard.target

[Unit]
Description=mongo shard target allowing to start/stop all mongo-shard@.service instances at once
PartOf=mongo.target

[Install]
WantedBy=mongo.target

/usr/lib/systemd/system/mongo.target

[Unit]
Description=mongo target allowing to start/stop all mongo*.service instances at once

[Install]
WantedBy=multi-user.target

载入服务:

# systemctl daemon-reload
# systemctl enable mongo-shard@01
# systemctl enable mongo-shard@02
# systemctl enable mongo-shard@03
# systemctl enable mongo-config
# systemctl enable mongos
# systemctl enable mongo-shard.target
# systemctl enable mongo.target

现在就可以方便地管理MongoDB服务了:

# systemctl start mongo-shard.target    # 启动所有shard服务
# systemctl start mongo.target          # 启动所有shard、config、mongos服务

4.3 配置副本集

config和shard服务本质上都是mongod进程,将他们都配置为三副本模式。下面的操作可以在三个节点中的任意一个上执行,只需要执行一遍。

config副本集:

# mongo --port 27018
> use admin
> config = {
...    _id : "ussmongo-config",
...     members : [
...         {_id : 0, host : "10.212.36.38:27018" },
...         {_id : 1, host : "10.212.36.39:27018" },
...         {_id : 2, host : "10.212.36.40:27018" }
...     ]
... }
> rs.initiate(config);

shard01副本集:

# mongo --port 27101
> use admin
> config = {
...    _id : "ussmongo-shard03",
...     members : [
...         {_id : 0, host : "10.212.36.38:27101" },
...         {_id : 1, host : "10.212.36.39:27101" },
...         {_id : 2, host : "10.212.36.40:27101" }
...     ]
... }
> rs.initiate(config);

shard02副本集:

# mongo --port 27102
> use admin
> config = {
...    _id : "ussmongo-shard02",
...     members : [
...         {_id : 0, host : "10.212.36.39:27102" },
...         {_id : 1, host : "10.212.36.40:27102" },
...         {_id : 2, host : "10.212.36.38:27102" }
...     ]
... }
> rs.initiate(config);

shard03副本集:

# mongo --port 27103
> use admin
> config = {
...    _id : "ussmongo-shard03",
...     members : [
...         {_id : 0, host : "10.212.36.40:27103" },
...         {_id : 1, host : "10.212.36.38:27103" },
...         {_id : 2, host : "10.212.36.39:27103" }
...     ]
... }
> rs.initiate(config);

4.4 配置分片路由

mongos对外提供服务,是集群的入口。需要先将分片添加到mongos配置中:

# mongo --port 27017
> use admin
> sh.addShard("ussmongo-shard01/10.212.36.38:27101,10.212.36.39:27101,10.212.36.40:27101")
> sh.addShard("ussmongo-shard02/10.212.36.39:27102,10.212.36.40:27102,10.212.36.38:27102")
> sh.addShard("ussmongo-shard03/10.212.36.40:27103,10.212.36.38:27103,10.212.36.39:27103")
> sh.status();

到这里集群已经能够提供服务了。mongos是无状态的,在三个mongos之上配置负载均衡,就完成了MongoDB高可用集群的部署。

 

5. 启用访问控制

线上环境集群不可能使用免认证的方式,都要开启安全认证。MongoDB在开启了访问控制后,只有一次添加用户的机会,此后的操作都需要先认证通过。为了方便,我们先添加用户,然后再开启访问控制。

5.1 添加用户

连接上mongos添加的用户会保存在config副本集中,但是不会保存到shard副本集,因此添加用户的操作需要分别在config、shard01、shard02、shard03上执行。

config副本集:

# mongo --port 27018
> use admin
> db.createUser(
...   {
...     user: "admin",
...     pwd: "admin",
...     roles: ["userAdminAnyDatabase", "dbAdminAnyDatabase", "readWriteAnyDatabase", "clusterAdmin"]
...   }
... )

shard01副本集:

# mongo --port 27101
> use admin
> db.createUser(
...   {
...     user: "admin",
...     pwd: "admin",
...     roles: ["userAdminAnyDatabase", "dbAdminAnyDatabase", "readWriteAnyDatabase", "clusterAdmin"]
...   }
... )

shard02副本集:

# mongo --port 27102
> use admin
> db.createUser(
...   {
...     user: "admin",
...     pwd: "admin",
...     roles: ["userAdminAnyDatabase", "dbAdminAnyDatabase", "readWriteAnyDatabase", "clusterAdmin"]
...   }
... )

shard03副本集:

# mongo --port 27103
> use admin
> db.createUser(
...   {
...     user: "admin",
...     pwd: "admin",
...     roles: ["userAdminAnyDatabase", "dbAdminAnyDatabase", "readWriteAnyDatabase", "clusterAdmin"]
...   }
... )

5.2 启用访问控制

1) 创建秘钥文件

启用访问控制之后,外部访问MongoDB服务需要进行身份验证,而mongos访问config和shard服务则是通过配置的秘钥文件。

# openssl rand -base64 756 >/data/mongodb/ussmongo.key
# chmod 0600 /data/mongodb/ussmongo.key
# chown mongod:mongod /data/mongodb/ussmongo.key

将密钥文件复制到所有节点上。

2) 添加security配置

mongos的配置文件添加如下配置:

security:
  keyFile: /data/mongodb/ussmongo.key

config和shard的配置文件添加如下配置:

security:
  authorization: enabled
  keyFile: /data/mongodb/ussmongo.key

3) 重启服务

在所有节点上重启所有MongoDB服务:

# systemctl restart mongo.target

 

至此带访问控制的MongoDB高可用集群就部署完成了。

 

参考资料

mongodb 3.4 集群搭建升级版 五台集群

Configuration File Options — MongoDB Manual

 

posted @ 2018-08-16 16:27 Sai18 阅读(...) 评论(...) 编辑 收藏