mongodb 3.4 学习 (一) 安装

https://www.mongodb.com/blog/post/capacity-planning-and-hardware-provisioning-mongodb-ten-minutes

安装

yum -y install mongodb-org*
systemctl enable mongod && systemctl restart mongod

mongo命令行客户端登录有警告，用以下方法消除

#1. 数据目录需要用xfs
 ** WARNING: Using the XFS filesystem is strongly recommended with the WiredTiger storage engine
 **          See http://dochub.mongodb.org/core/prodnotes-filesystem

opt分区格式化为xfs，将数据目录/var/lib/mongo迁移到/opt，并建立软链接
cd /var/lib && mv mongo /opt && ln -s /opt/mongo mongo

#2. mongodb默认是无密码登录，有风险 
 ** WARNING: Access control is not enabled for the database.
 **          Read and write access to data and configuration is unrestricted.
 
建立管理员admin，对所有数据库有userAdmin权限
db.createUser({user: 'admin', pwd: '@admin', roles: [{role: 'userAdminAnyDatabase', db: 'admin'}]})

建立用户test，仅对test数据库有读写权限
use test
db.createUser({user: 'test', pwd: '@test', roles: [{role: 'readWrite', db: 'test'}]})

重新启动mongo服务，启动权限认证功能
echo -e "\nsecurity:\n  authorization: enabled" >> /etc/mongod.conf
systemctl restart mongod

用户认证
db.auth('admin', '@admin')

#3. linux的cpu各核内存共享的机制，在bios或者内核禁用
 ** WARNING: You are running on a NUMA machine.
 **          We suggest launching mongod like this to avoid performance problems:
 **              numactl --interleave=all mongod [other options]

vim /etc/default/grub
GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet numa=off"

grub2-mkconfig -o /boot/grub2/grub.cfg

#4. transparent_hugepage机制，在内核中禁用
 ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
 **        We suggest setting it to 'never'
 
 ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
 **        We suggest setting it to 'never'

cat > /lib/systemd/system/disable_transparent_hugepage.service << EOF
[Unit]
Description="Disable Transparent Hugepage before MongoDB boots"
Before=mongodb.service 

[Service]
Type=oneshot
ExecStart=/bin/bash -c 'echo never > /sys/kernel/mm/transparent_hugepage/enabled'
ExecStart=/bin/bash -c 'echo never > /sys/kernel/mm/transparent_hugepage/defrag'

[Install]
RequiredBy=mongod.service
EOF

systemctl enable disable_transparent_hugepage && systemctl start disable_transparent_hugepage
systemctl restart mongod