Installing MongoDB

This section provides a step-by-step guide to installing MongoDB.

Before you begin

Make sure the following things are in place, before you start installation:

  • Create a mount point on the instance volume (nvme).
  • Attach the additional SSD to the newly created mount point, so that the initial nvme volume size can be expanded.

Procedure

  1. Install MongoDB.
    1. Edit the /etc/yum.repos.d/mongodb-org-6.0.repo with the following content. 
      vi /etc/yum.repos.d/mongodb-org-6.0.repo
[mongodb-org-6.0]
name=MongoDB Repository baseurl= https://repo.mongodb.org/yum/redhat/8/mongodb-org/6.0/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://pgp.mongodb.com/server-6.0.asc
    2. Install the MongoDB. 
      yum install -y mongodb-org
    3. Update the yum.conf with bind IP address, port number, storage db path. 
      echo "exclude=mongodb-org,mongodb-org-database,mongodb-org-server,mongodb-mongosh,mongodb-org-mongos,mongodb-org-tools" >> /etc/yum.conf
sed -i "s|OPTIONS=-f /etc/mongod.conf|OPTIONS=--replSet cdprsg -f /etc/mongod.conf" /usr/lib/systemd/system/mongod.service
 vi /etc/mongod.conf

      Use the following the mongodb.conf file.

      # mongod.conf

# for documentation of all options, see:
#   http://docs.mongodb.org/manual/reference/configuration-options/

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

# Where and how to store data.
storage:
  dbPath: /sdd
  journal:
    enabled: true
#  engine:
#  wiredTiger:

# network interfaces
net:
  port: 51090
  bindIp: mongodbhost1

# how the process runs
processManagement:
  timeZoneInfo: /usr/share/zoneinfo

security:
  authorization: disabled

operationProfiling:
  mode: all
  slowOpThresholdMs: 200

#replication:
#  replSetName: "cdprsg"

#sharding:

## Enterprise-Only Options:

#auditLog:

#snmp:
    4. Now, change the file ownership and reload deamon usng the following commands. 
      chown -R mongod: /sdd
chcon -R --reference=/var/lib/mongo /sdd
semanage port -a -t mongod_port_t -p tcp 51090
systemctl daemon-reload
systemctl restart mongod
systemctl status mongod
    5. Validate the connectivity with other nodes. 
      nc -zv mongodbhost2 5190
nc -zv mongodbhost3 5190
nc -zv mongodbhost4 5190
nc -zv mongodbhost5 5190
    6. Connect the MongoDB cluster with the specified hostname. 
      mongosh --host mongodbhost1 --port 51090
    7. Configure replica set and initiate it. 
      use admin;
conf={ _id: "cdprsg", members: [ { _id: 0, host: "mongodbhost1:51090", tags: {usage: "schedule"} }, { _id: 1, host: "mongodbhost2:51090", tags: {usage: "schedule" }}, { _id: 2, host: "mongodbhost3:51090", tags: {usage: "segloader" }}, { _id: 3, host: "mongodbhost4:51090", tags: {usage: "analytics" }}] }
rs.initiate(conf);
rs.addArb("mongodbhost5:51090");
conf = rs.conf()
conf.members[3].hidden = true
rs.status()
    8. Create three users in the admin database with specific roles and privileges. 
      use admin;
db.createUser( { user: "rtsms", pwd: "<password>", roles: [{ role: "readWrite", db: "segmentation" }, { role: 'dbAdmin', db: 'segmentation' }] });
db.createUser( { user: "segdbconnector", pwd: "<password>", roles: [{ role: "readWrite", db: "segmentation" }] });
db.createUser( { user: "pmm", pwd: "Vism6lUIkw5O6BX7fxJB9w", roles: [ { role: 'backup', db: 'admin' }, { role: 'clusterMonitor', db: 'admin' }, { role: 'read', db: 'local' }, { role: 'readWrite', db: 'admin' }, { role: 'restore', db: 'admin' }] });
  2. Install the Node Exporter.
    1. Download the latest node exporter package, and extract the package. 
      wget https://github.com/prometheus/node_exporter/releases/download/v1.7.0/node_exporter-1.7.0.linux-amd64.tar.gz
tar xfz node_exporter-*.*-amd64.tar.gz
    2. Move the extracted binary from the extracted directory to the local bin location. 
      sudo mv node_exporter-*.*-amd64/node_exporter /usr/local/bin/
    3. Optionally, create a user. 
      sudo useradd -rs /bin/false node_exporter
    4. Update the service file as shown below: 
      vi /etc/systemd/system/node_exporter.service
[Unit]
Description=Node Exporter
After=network.target
[Service]
User=node_exporter
Group=node_exporter
Type=simple
ExecStart=/usr/local/bin/node_exporter
[Install]
WantedBy=multi-user.target
    5. Reload Daemon to ensure the Node Exporter service is properly configured and running. 
      restorecon -Rv /usr/local/bin
systemctl daemon-reload
systemctl start node_exporter
systemctl status node_exporter
systemctl enable node_exporter
curl -kv  http://localhost:9100/metrics
  3. Install the MongoDB Exporter.
    1. Download the MongoDB exporter, a tool for collecting metrics about your MongoDB cluster. 
      wget  https://github.com/percona/mongodb_exporter/releases/download/v0.40.0/mongodb_exporter-0.40.0.linux-64-bit.rpm
    2. Install the MongoDB package. 
      rpm -Uhv mongodb_exporter-0.40.0.linux-64-bit.rpm
    3. Update the MongoDB exporter service file. 
      vi /etc/systemd/system/mongodb_exporter.service
[Unit]
Description=Prometheus MongoDB Exporter
Documentation= https://github.com/percona/mongodb_exporter
After=network.target
[Service]
Type=simple
User=mongodb_exporter
Group=mongodb_exporter
 Environment="OPTIONS=--mongodb.uri=mongodb://pmm:Wrtu9v0UGaqgohsYePtiMQ==@mongodbhost1:51090 --compatible-mode"
EnvironmentFile=-/etc/default/mongodb_exporter
ExecStart=/usr/bin/mongodb_exporter $OPTIONS
SyslogIdentifier=mongodb_exporter
Restart=always
[Install]
WantedBy=multi-user.target
    4. Reload Daemon to ensure the MongoDB exporter service is properly configured and running. 
      systemctl daemon-reload
systemctl start mongodb_exporter
systemctl status mongodb_exporter
systemctl enable mongodb_exporter
curl -kv  http://localhost:9216/metrics