The local metrics plugin stores the values on memory.
Parameters
default_labels
Specifies the default labels for the metrics. (default: {agent: "Fluentd", hostname: "#{Socket.gethostname}"})
labels
Specifies other custom labels for the metrics. (default: {})
Example
With this configuration:
<system>
<metrics>
@type local
</metrics>
</system>
The above configuration will save the internal metrics for plugins on memory. As a result, you can retrive metrics from memory and also you can replace with your custom metrics plugin.
Actually, @type local metrics plugin has equivalent functionality for previous single value based Ruby instance variables. This behavior will be changed by other 3rd party plugins.