CentOS7安装使用MongoDB 3.4 单节点(for Hygieia)

phphelloword

2019-06-27

安装准备

NUMA Settings
Running MongoDB on a system with Non-Uniform Access Memory (NUMA) can cause a number of operational problems, including slow performance for periods of time and high system process usage.
```
sysctl -w vm.zone_reclaim_mode=0
```
Kernel and File Systems
When running MongoDB in production on Linux, you should use Linux kernel version 2.6.36 or later,
with either the XFS or EXT4 filesystem. If possible, use XFS as it generally performs better with MongoDB.
XFS is the default file system for CentOS7.

DNS settings

cat > /etc/resolv.conf << EOF
nameserver 172.20.224.134
EOF

NTP Settings

Use the Network Time Protocol (NTP) to synchronize time among your hosts. This is especially important in sharded clusters.

yum -y install chrony
#sync time from local time server
sed -i '/^server*/d' /etc/chrony.conf
sed -i -e '/^# Please consider*/a\server ntp01' /etc/chrony.conf
systemctl enable chronyd && systemctl restart chronyd

Turn off Atime
Turn off atime for the storage volume containing the database files.
add mount option "noatime,nodiratime" in /etc/fstab
```
vim /etc/fstab
/dev/mapper/VolGroup-lv_data /data     xfs    defaults,noatime,nodiratime     1 1
```
ulimt settings
Set the file descriptor limit, -n, and the user process limit (ulimit), -u, above 20,000, according to the suggestions in the ulimit reference.
```
#check ulimit
ulimit -a

#set ulimit for mongod
cat >> /etc/security/limits.conf << EOF
 mongod soft nproc 65535
 mongod hard nproc 65535
EOF
```
Disable Transparent Huge Pages
MongoDB performs better with normal (4096 bytes) virtual memory pages.
```
echo never > /sys/kernel/mm/transparent_hugepage/enabled;
echo never > /sys/kernel/mm/transparent_hugepage/defrag;
chmod +x /etc/rc.d/rc.local
```
For CentOS 6 , refer to Disable Transparent Huge Pages
Disable selinux
It's better to set selinux permissive ranther than disabled
```
sed -i s/^SELINUX=.*/SELINUX=permissive/g /etc/selinux/config
```

Disable iptables

service iptables stop && chkconfig iptables off
service ip6tables stop && chkconfig ip6tables off

sshd tunning

disable dns search when connecting to this server;
disable PasswordAuthentication confirm when ssh to other servers.

sed -i 's/^#UseDNS yes/UseDNS no/' /etc/ssh/sshd_config
sed -i 's/^#PasswordAuthentication no/PasswordAuthentication yes/g' /etc/ssh/sshd_config

Set the readahead setting
Setting a higher readahead benefits sequential I/O operations. However, since MongoDB disk access patterns are generally random, setting a higher readahead provides limited benefit or performance degradation.
- For the WiredTiger storage engine, a readahead of 0 or 16 provides optimal MongoDB performance.
- For the MMAPv1 storage enginem, A readahead of 32 (16 kB) often works well.
```
#get the readahead settings of block device
blockdev --report
#change the readahead settings
blockdev --setra <value> <device>
blockdev --setra  256 /dev/xvda
```

安装mongodb

设置安装yum源

国内使用阿里云镜像源

cat > /etc/yum.repos.d/mongodb-org-3.4.repo << EOF
[mongodb-org-3.4]
name=MongoDB Repository
#baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/3.4/x86_64/
baseurl=https://mirrors.aliyun.com/mongodb/yum/redhat/\$releasever/mongodb-org/3.4/x86_64/
gpgcheck=0
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-3.4.asc
EOF

安装mongodb

yum -y install mongodb-org
systemctl enable mongod
systemctl start mongod

修改默认配置（可选）

同时注释掉只监听localhost的设置：

mkdir -pv /data/mongodb/storage
chown -R mongod /data/mongodb/storage

vim /etc/mongod.conf

# Where and how to store data.
storage:
  dbPath: /data/mongodb/storage  #修改为数据存储目录，并确保mongod用户可读写
  journal:
    enabled: true
 

# network interfaces
net:
  port: 27017
#  bindIp: 127.0.0.1  #默认监听本地lo，注释掉interfaces.

systemctl restart mongod

创建数据库

#登录数据库
mongo

#创建数据库dashboarddb
use dashboarddb

#Create db user
db.createUser(
  {
    user: "dashboarduser",
    pwd: "dbpassword",
    roles: [
    {role: "readWrite", db: "dashboarddb"}
    ]
  })

centos6 安装mongodb请参考