Targets

Targets care about the final handling of metric results, after all measurements have been executed.

They are normally storing the results in a specific format on a specific system. E.g. locally as csv file or as entry on a metric system like Prometheus.

There is no direct link between a metric and a target, as a metric does not need to know, how its result get handled.

Targets get selected by the user during the call of Metric-Farmer, e.g. metricfarmer print, or by using the related Settings: targets_default or targets_always.

Page content

Target types

Predefined targets

Metric-Farmer provides the predefined targets print, print_json, file_text, file_json, file_csv and db_sqlite.

This is the content of the .farm-file, which defines the predefined sources:

{
  "targets": {
    "print": {
      "class": "mf.print",
      "description": "Prints the measurement results on std.out"
    },

    "print_json": {
      "class": "mf.print_json",
      "description": "Prints the measurement results as json on std.out"
    },

    "file_text": {
      "class": "mf.file_text",
      "description": "Stores metric results in a simple text file.",
      "path": "metric_results.txt",
      "override": true
    },

    "file_json": {
      "class": "mf.file_json",
      "description": "Stores metric results in a json file.",
      "path": "metric_results.json",
      "override": true
    },

    "file_csv": {
      "class": "mf.file_csv",
      "description": "Stores metric results in a csv file.",
      "path": "metric_results.csv",
      "override": false,
      "delimiter": ","
    },

    "db_sqlite": {
      "class": "mf.db_sqlite",
      "description": "Stores metric results in a sqlite file.",
      "path": "metric_results.db",
      "table": "metrics"
    }
  }
}

Please take the above file content as reference about what defaults are set/used for each target. For instance the use file path of csv output.

The targets can be simply used as argument in the Metric-Farmer call: metricfarmer db_sqlite.

Own targets

Targets can be defined in each .farm-file. After definition they can directly be selected and used by the user.

Example:

{
  "targets": {
    "file_csv": {
      "class": "mf.file_csv",
      "description": "Stores metric results in a csv file.",
      "path": "metric_results.csv",
      "override": false,
      "delimiter": ","
    }
  }
}

Targets must have an unique name, which is used only once in all loaded .farm-files.

They also need to reference a target class of a loaded extension:

"file_csv": {
  "class": "mf.file_csv"
}

The target class defines what other parameters are needed. So please take a look into the related documentation of target classes.

Run metricfarmer --list to get a list off all extension and their provided target classes.

Target classes

Predefined target classes

This list shows only target classes provided by Metric-Farmer. If you have installed some extensions, this list might be much bigger. Please run metricfarmer --list to see what is really available on your system.

mf.print

Prints the result on the command line.

Does not support any parameters.

mf.print_json

Prints the result as json format on the command line.

Does not support any parameters.

mf.file_text

Writes the results to a text file.

Parameters

Parameter	Description	Default	Required
path	File path to use	metric_results.txt	No
override	If true, existing file gets replace, otherwise an error is thrown	False	No

mf.file_json

Writes the results to a json file.

Same out put as target print_json.

Parameters

Parameter	Description	Default	Required
path	File path to use	metric_results.txt	No
override	If true, existing file gets replace, otherwise an error is thrown	False	No

mf.file_csv

Writes the results to a csv file.

If override is set to false and a csv file already exists, new results with get added.

Parameters

Parameter	Description	Default	Required
path	File path to use	metric_results.txt	No
override	If true, existing file gets replace, otherwise an error is thrown	False	No
delimiter	Character to use as delimiter in csv file	,	No

mf.db_sqlite

Writes results to a local sqlite database file.

File path and table can be configured by the related parameters. But the needed table columns are fixed: metric, timestamp, result

New data is always added and existing data is kept.

The database table may look like this after several executions of metricfarmer db_sqlite.

You can use a sqlite database viewer like sqlitebrowser to analyze the data.

Parameters

Parameter	Description	Default	Required
path	File path to use	metric_results.db	No
table	Name of the table to use for string result data	metrics	No