Prometheus is a leading time series database and monitoring solution that is open source. Prometheus collects metrics from configured targets at given intervals, evaluates rule expressions, displays the results, and can trigger alerts if some condition is observed to be true.
Here we will look at how to configure Prometheus MySQL exporters on database servers, both MySQL MariaDB and visualizing data with Grafana. This will enable you to have a good view of database performance and know where to check whenever you have issues. The configuration of alerting rules is beyond the scope of this guide, but I’ll try to cover it in the next guides.
This guide will have three main steps
Installation and configuration of Prometheus server
Installation and configuration of MySQL Prometheus exporter on database servers
Creating / Importing MySQL Grafana dashboards – We will use readily baked dashboards by Percona.
Step 1: Install and Configure Prometheus server
Step 2: Install and Configure Prometheus MySQL Exporter
Once you have installed Prometheus server, you need to install Prometheus exporter for MySQL server metrics. Note that the supported MySQL versions is 5.5 and up.
Add Prometheus system user and group:
sudo groupadd --system prometheus
sudo useradd -s /sbin/nologin --system -g prometheus prometheus
This user will manage the exporter service.
Download and install Prometheus MySQL Exporter:
This should be done on MySQL / MariaDB servers, both slaves and master servers. You may need to check Prometheus MySQL exporter releases page for the latest release, then export the latest version to VER variable as shown below:
Download latest release of MySQL exporter:
curl -s https://api.github.com/repos/prometheus/mysqld_exporter/releases/latest | grep browser_download_url | grep linux-amd64 | cut -d '"' -f 4 | wget -qi -
tar xvf mysqld_exporter*.tar.gz
sudo mv mysqld_exporter-*.linux-amd64/mysqld_exporter /usr/local/bin/
sudo chmod +x /usr/local/bin/mysqld_exporter
Confirm installation by checking version of mysqld_exporter:
$ mysqld_exporter --version
mysqld_exporter, version 0.14.0 (branch: HEAD, revision: ca1b9af82a471c849c529eb8aadb1aac73e7b68c)
build user: root@401d370ca42e
build date: 20220304-16:25:15
go version: go1.17.8
platform: linux/amd64
Create Prometheus exporter database user
The user should have PROCESS, SELECT, REPLICATION CLIENT grants:
CREATE USER 'mysqld_exporter'@'localhost' IDENTIFIED BY 'StrongPassword' WITH MAX_USER_CONNECTIONS 2;
GRANT PROCESS, REPLICATION CLIENT, SELECT ON *.* TO 'mysqld_exporter'@'localhost';
FLUSH PRIVILEGES;
EXIT
If you have a Master-Slave database architecture, create user on the master servers only.
WITH MAX_USER_CONNECTIONS 2 is used to set a max connection limit for the user to avoid overloading the server with monitoring scrapes under heavy load.
Configure database credentials
Create database credentials file:
sudo vim /etc/.mysqld_exporter.cnf
Add correct username and password for user create
[client]
user=mysqld_exporter
password=StrongPassword
Set ownership permissions:
sudo chown root:prometheus /etc/.mysqld_exporter.cnf
Create systemd unit file ( For Systemd systems )
This is for systemd servers, for SysV init system, use Prometheus MySQL exporter init script for SysV init system
Create a new service file:
sudo vim /etc/systemd/system/mysql_exporter.service
Add the following content
[Unit]
Description=Prometheus MySQL Exporter
After=network.target
User=prometheus
Group=prometheus
[Service]
Type=simple
Restart=always
ExecStart=/usr/local/bin/mysqld_exporter \
--config.my-cnf /etc/.mysqld_exporter.cnf \
--collect.global_status \
--collect.info_schema.innodb_metrics \
--collect.auto_increment.columns \
--collect.info_schema.processlist \
--collect.binlog_size \
--collect.info_schema.tablestats \
--collect.global_variables \
--collect.info_schema.query_response_time \
--collect.info_schema.userstats \
--collect.info_schema.tables \
--collect.perf_schema.tablelocks \
--collect.perf_schema.file_events \
--collect.perf_schema.eventswaits \
--collect.perf_schema.indexiowaits \
--collect.perf_schema.tableiowaits \
--collect.slave_status \
--web.listen-address=0.0.0.0:9104
[Install]
WantedBy=multi-user.target
If your server has a public and private network, you may need to replace 0.0.0.0:9104 with private IP, e.g. 192.168.4.5:9104
When done, reload systemd and start mysql_exporter service.
sudo systemctl daemon-reload
sudo systemctl enable mysql_exporter
sudo systemctl start mysql_exporter
Configure MySQL endpoint to be scraped by Prometheus Server
Login to your Prometheus server and Configure endpoint to scrape. Below is an example for two MySQL database servers.
scrape_configs:
- job_name: server1_db
static_configs:
- targets: ['10.10.1.10:9104']
labels:
alias: db1
- job_name: server2_db
static_configs:
- targets: ['10.10.1.11:9104']
labels:
alias: db2
The first server has the IP address 10.10.1.10 and the second one is 10.10.1.11. Add other targets using the similar format. Job names should be unique for each target.
Note: Prometheus Server should be able to reach the targets over the network. Ensure you have correct network/firewall configurations.
Step 3: Creating / Importing MySQL Grafana dashboards
Now that we have the targets configured and agents to be monitored, we should be good to add Prometheus data source to Grafana so that we can do metrics visualization. If you don’t have a ready Grafana server, use any of the guides below to install Grafana:
Install Grafana and InfluxDB on CentOS 7
How to Install Grafana on Ubuntu and Debian
When installed, login to admin dashboard and add Datasource by navigating to Configuration > Data Sources.
Name: Prometheus
Type: Prometheus
URL: http://localhost:9090
If Prometheus server is not on the same host as Grafana, provide IP address of the server.
Create / Import Grafana Dashboard for MySQL Prometheus exporter
If you don’t have all the golden time to create your own dashboards, you can use one created by Percona, they are Open source.
Let’s download MySQL_Overview dashboard which has a good overview of database performance.
mkdir ~/grafana-dashboards
cd ~/grafana-dashboards
wget https://raw.githubusercontent.com/percona/grafana-dashboards/master/dashboards/MySQL_Overview.json
Upload Prometheus MySQL dashboard(s) to grafana
Go to Dashboards > Import > Upload .json file
Locate the directory with dashboard file and import.
If you wish to import all Percona dashboards for Prometheus, install them on Grafana server.
git clone https://github.com/percona/grafana-dashboards.git
cp -r grafana-dashboards/dashboards /var/lib/grafana/
You need to restart Grafana server to import these dashboards.
sudo systemctl restart grafana-server
sudo service grafana-server restart
You can then start using the dashboards on Grafana.
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