Getting Started with Telegraf

Getting Started with Telegraf

Telegraf is an agent written in Go for collecting metrics and writing them into InfluxDB or other possible outputs. This guide will get you up and running with Telegraf. It walks you through the download, installation, and configuration processes, and it shows how to use Telegraf to get data into InfluxDB.

Download and Install Telegraf

Follow the instructions in the Telegraf section on the Downloads page.

Configuration

Configuration file location by installation type

• macOS Homebrew: /usr/local/etc/telegraf.conf
• Linux debian and RPM packages: /etc/opt/telegraf/telegraf.conf
• Standalone Binary: see the next section for how to create a configuration file

Creating and Editing the Configuration File

Before starting the Telegraf server you need to edit and/or create an initial configuration that specifies your desired plugins (where the metrics come from) and outputs (where the metrics go). There are several ways to create and edit the configuration file. Here, we’ll generate a configuration file and simultaneously specify the desired plugins with the -filter flag and the desired output with the -outputfilter flag.

In the example below, we create a configuration file called telegraf.conf with two plugins: one that reads metrics about the system’s cpu usage (cpu) and one that reads metrics about the system’s memory usage (mem). telegraf.conf specifies InfluxDB as the desired ouput.

telegraf -sample-config -filter cpu:mem -outputfilter influxdb > telegraf.conf

Start the Telegraf Server

Start the Telegraf server and direct it to the relevant configuration file:

macOS Homebrew

telegraf -config telegraf.conf

Linux debian and RPM packages

sudo service telegraf start

Ubuntu 15+

systemctl start telegraf

Results

Once Telegraf is up and running it’ll start collecting data and writing them to the desired output.

Returning to our sample configuration, we show what the cpu and mem data look like in InfluxDB below. Note that we used the default plugin and output configuration settings to get these data.

• List all measurements in the telegraf database:

  > SHOW MEASUREMENTS
  name: measurements
  ------------------
  name
  cpu_usage_guest
  cpu_usage_guest_nice
  cpu_usage_idle
  cpu_usage_iowait
  cpu_usage_irq
  cpu_usage_nice
  cpu_usage_softirq
  cpu_usage_steal
  cpu_usage_system
  cpu_usage_user
  mem_available
  mem_available_percent
  mem_buffered
  mem_cached
  mem_free
  mem_total
  mem_used
  mem_used_percent

Notice that each measurement has the name of the plugin prepended to it.

• Select a sample of the data in the measurement cpu_usage_idle:

  > SELECT value FROM cpu_usage_idle WHERE cpu='cpu-total' LIMIT 5
  name: cpu_usage_idle
  --------------------
  time			                value
  2015-12-08T21:39:20Z	  98.04902451225612
  2015-12-08T21:39:30Z	  97.70028746406699
  2015-12-08T21:39:40Z	  98.37520309961255
  2015-12-08T21:39:50Z	  98.17522809648794
  2015-12-08T21:40:00Z	  96.84881830686507

Notice that the timestamps occur at rounded ten second intervals (that is, :00, :10, :20, and so on) - this is a configurable setting.

That’s it! You now have the foundation for using Telegraf to collect metrics and write them to your output of choice.