This post explains how you can quickly start
using such trending tools as Prometheus and
Grafana for monitoring and graphing of MySQL and
system performance.
I will try to keep this blog as short as possible, so you can quickly set things up before getting bored. I plan to cover the details in the next few posts. I am going to go through the installation process here in order to get some really useful and good-looking graphs in the end.
Overview
Prometheus is an open-source service monitoring system and time series database. In short, the quite efficient daemon scrapes metrics from remote machines using HTTP protocol and stores data in the local time-series database. Prometheus provides a simple web interface, a very powerful query language, HTTP API etc. However, the storage is not designed to be durable for the time being.
The remote machines need to run exporters to expose metrics to Prometheus. We will be using the following two:
- node_exporter – for machine metrics.
- mysqld_exporter – for MySQL server metrics
Grafana is an open source, feature-rich metrics dashboard and graph editor for Graphite, Elasticsearch, OpenTSDB, Prometheus and InfluxDB. It is a powerful tool for visualizing large-scale measurement data and designed to work with time-series. Grafana supports different types of graphs, allows for custom representation of individual metrics on the graph and various methods of authentication including LDAP.
Diagram
Here is a diagram of the setup we are going to use:
Prometheus setup
To install on the monitor host.
Get the latest tarball from Github.
wget https://github.com/prometheus/prometheus/releases/download/0.17.0rc2/prometheus-0.17.0rc2.linux-amd64.tar.gz mkdir /opt/prometheus tar zxf prometheus-0.17.0rc2.linux-amd64.tar.gz -C /opt/prometheus --strip-components=1
Create a simple config:
cat << EOF > /opt/prometheus/prometheus.yml
global:
scrape_interval: 5s
evaluation_interval: 5s
scrape_configs:
- job_name: linux
target_groups:
- targets: ['192.168.56.107:9100']
labels:
alias: db1
- job_name: mysql
target_groups:
- targets: ['192.168.56.107:9104']
labels:
alias: db1
EOF
where 192.168.56.107 is the IP address of the db host we are going to monitor and db1 is its short name. Note, the “alias” label is important here because we rely on it in the predefined dashboards below to get per host graphs.
Start Prometheus in foreground:
[root@centos7 ~]# cd /opt/prometheus [root@centos7 prometheus]# ./prometheus prometheus, version 0.17.0rc2 (branch: release-0.17, revision: 667c221) build user: fabianreinartz@macpro build date: 20160205-13:35:53 go version: 1.5.3 INFO[0000] Loading configuration file prometheus.yml source=main.go:201 INFO[0000] Loading series map and head chunks... source=storage.go:297 INFO[0000] 0 series loaded. source=storage.go:302 WARN[0000] No AlertManager configured, not dispatching any alerts source=notification.go:165 INFO[0000] Starting target manager... source=targetmanager.go:114 INFO[0000] Target manager started. source=targetmanager.go:168 INFO[0000] Listening on :9090 source=web.go:239
Now we can access Prometheus’ built-in web interface by http://monitor_host:9090
If you look at the Status page from the top menu, you will see
that our monitoring targets are down so far. Now let’s setup them
– prometheus exporters.
Prometheus exporters setup
Install on the db host. Of course, you can use the same monitor host for the experiment. Obviously, this node must run MySQL.
Download exporters from here and there.
wget https://github.com/prometheus/node_exporter/releases/download/0.12.0rc3/node_exporter-0.12.0rc3.linux-amd64.tar.gz wget https://github.com/prometheus/mysqld_exporter/releases/download/0.7.1/mysqld_exporter-0.7.1.linux-amd64.tar.gz mkdir /opt/prometheus_exporters tar zxf node_exporter-0.12.0rc3.linux-amd64.tar.gz -C /opt/prometheus_exporters tar zxf mysqld_exporter-0.7.1.linux-amd64.tar.gz -C /opt/prometheus_exporters
Start node_exporter in foreground:
[root@centos7 ~]# cd /opt/prometheus_exporters [root@centos7 prometheus_exporters]# ./node_exporter INFO[0000] No directory specified, see --collector.textfile.directory source=textfile.go:57 INFO[0000] Enabled collectors: source=node_exporter.go:146 INFO[0000] - filesystem source=node_exporter.go:148 INFO[0000] - loadavg source=node_exporter.go:148 INFO[0000] - time source=node_exporter.go:148 INFO[0000] - vmstat source=node_exporter.go:148 INFO[0000] - diskstats source=node_exporter.go:148 INFO[0000] - filefd source=node_exporter.go:148 INFO[0000] - mdadm source=node_exporter.go:148 INFO[0000] - meminfo source=node_exporter.go:148 INFO[0000] - netdev source=node_exporter.go:148 INFO[0000] - textfile source=node_exporter.go:148 INFO[0000] - entropy source=node_exporter.go:148 INFO[0000] - stat source=node_exporter.go:148 INFO[0000] - uname source=node_exporter.go:148 INFO[0000] - conntrack source=node_exporter.go:148 INFO[0000] - netstat source=node_exporter.go:148 INFO[0000] - sockstat source=node_exporter.go:148 INFO[0000] - version source=node_exporter.go:148 INFO[0000] Starting node_exporter v0.12.0rc3 at :9100 source=node_exporter.go:167
Unlike node_exporter, mysqld_exporter wants MySQL credentials. Those privileges should be sufficient:
mysql> GRANT REPLICATION CLIENT, PROCESS ON *.* TO 'prom'@'localhost' identified by 'abc123'; mysql> GRANT SELECT ON performance_schema.* TO 'prom'@'localhost';
Create .my.cnf and start mysqld_exporter in foreground:
[root@centos7 ~]# cd /opt/prometheus_exporters [root@centos7 prometheus_exporters]# cat << EOF > .my.cnf [client] user=prom password=abc123 EOF [root@centos7 prometheus_exporters]# [root@centos7 prometheus_exporters]# ./mysqld_exporter -config.my-cnf=".my.cnf" INFO[0000] Starting Server: :9104 file=mysqld_exporter.go line=1997
At this point we should see our endpoints are up and running on
the Prometheus Status page:
Grafana setup
Install on the monitor host.
Grafana has RPM and DEB packages. The installation is as simple as
installing one package.
RPM-based system:
yum install https://grafanarel.s3.amazonaws.com/builds/grafana-2.6.0-1.x86_64.rpm
or APT-based one:
wget https://grafanarel.s3.amazonaws.com/builds/grafana_2.6.0_amd64.deb apt-get install -y adduser libfontconfig dpkg -i grafana_2.6.0_amd64.deb
Open and edit the last section of /etc/grafana/grafana.ini resulting in the following ending:
[dashboards.json] enabled = true path = /var/lib/grafana/dashboards
Percona has built the predefined dashboards for Grafana with Prometheus for you.
Let’s get them deployed:
git clone https://github.com/percona/grafana-dashboards.git cp -r grafana-dashboards/dashboards /var/lib/grafana
Finally, start Grafana:
service grafana-server start
At this point, we are one step before being done. Login into Grafana web interface http://monitor_host:3000 (admin/admin).
Go to Data Sources and add one for Prometheus:
Now check out the dashboards and graphs. Say choose “System
Overview” and period “Last 5 minutes” on top-right. You should
see something similar:
If your graphs are not populating ensure the system time is
correct on the monitor host.
Samples
Here are some real-world samples (images are clickable and
scrollable):
Enjoy!
Conclusion
Prometheus and Grafana is a great tandem for enabling monitoring and graphing capabilities for MySQL. The tools are pretty easy to deploy, they are designed for time series with high efficiency in mind. In the next blog posts I will talk more about technical aspects, problems and related stuff.