Memory metrics

The Memory (mem) input plugin gathers information about the memory and swap usage of the running system every certain interval of time and reports the total amount of memory and the amount of free available.

Get started

To get memory and swap usage from your system, you can run the plugin from the command line or through the configuration file:

Command line

Run the following command from the command line, noting this is for a Linux machine:

fluent-bit -i mem -t memory -o stdout -m '*'

Which outputs information similar to:

...
[0] memory: [[1751381087.225589224, {}], {"Mem.total"=>3986708, "Mem.used"=>560708, "Mem.free"=>3426000, "Swap.total"=>0, "Swap.used"=>0, "Swap.free"=>0}]
[0] memory: [[1751381088.228411537, {}], {"Mem.total"=>3986708, "Mem.used"=>560708, "Mem.free"=>3426000, "Swap.total"=>0, "Swap.used"=>0, "Swap.free"=>0}]
[0] memory: [[1751381089.225600084, {}], {"Mem.total"=>3986708, "Mem.used"=>561480, "Mem.free"=>3425228, "Swap.total"=>0, "Swap.used"=>0, "Swap.free"=>0}]
[0] memory: [[1751381090.228345064, {}], {"Mem.total"=>3986708, "Mem.used"=>561480, "Mem.free"=>3425228, "Swap.total"=>0, "Swap.used"=>0, "Swap.free"=>0}]
...

Threading

You can enable the threaded setting to run this input in its own thread.

Configuration file

In your main configuration file append the following:

fluent-bit.yaml

pipeline:
  inputs:
    - name: mem
      tag: memory

  outputs:
    - name: stdout
      match: '*'

fluent-bit.conf