Configuration YAML File

This file is mandatory and it is crucial. It is used to specify the main configuration of the simulation.

The file is a dictionary with the following keys:

  • engine (str), optional:

    The simulation engine to use. Only “simpy” is supported at the moment. Defaults to “simpy”.

  • global_params (dict), optional:

    A dictionary with global parameters to be used in the simulation. Defaults to an empty dictionary. These parameters can be accessed by any entity in the simulation using the get_global_param() function.

  • log_level (int or str), optional:

    The log level for the simulation. See set_log_level(). Defaults to “info”.

  • metrics (list of dict), optional:

    The list of metrics to collect. Defaults to an empty list. Each metric is a dictionary with the following keys:

    • “name” (str): The name of the metric.

    • “type” (str): The type of the metric. It can be “number”, “str”, or “dict”. “number” is a scalar metric, “str” is a string metric, and “dict” is a dictionary metric with custom columns.

    • “collect” (list). What to collect. It can contain “mean”, “std”, “var”, “min”, “max”, “percentiles”, “vector”. The most common type is “vector”, which collects all samples in the dedicated “./{output_dir}/{metric name}_vector.csv”. All other values are scalar aggregates, all stored in “./{output_dir}/{metric name}.csv”. The percentiles are 0, 25, 50, 75, 100. The format of these output files is described below in the output_dir parameter.

    • “columns” (list). The columns to collect for the metric. Only used for “dict” metrics. Every time a sample is collected, the values in this list are collected as columns in the output file. Every sample must be a dictionary with all these columns as keys. The value “timestamp” is reserved and will be automatically added to the columns and managed by the system.

  • num_processes (int), optional:

    The number of Python parallel processes to use to run the simulations. Defaults to 1. Different repetitions will be run in parallel processes.

  • num_rngs (int), optional:

    The number of independent random number generators (RNGs) to use in the simulation. Defaults to 1. A different seed will be used for each RNG at every repetition.

  • output_dir (str or None), optional:

    The output directory for the simulation, relative to the configuration file directory. Defaults to None, in which case no data will be stored.

    Aggregated metric data is stored (for each metric) in a csv files named “./{output_dir}/{metric name}.csv”. This file contains the metric values for each repetition (one repetition per row), where the columns are the metric values for each repetition. For example:

    mean, std, var, min, max
0.1, 0.01, 0.001, 0.05, 0.15
0.2, 0.02, 0.004, 0.1, 0.5
[...]

    In case the metric “collected” field also contains “vector”, then all samples (and their collection timestamp) are stored in a separate file named “./{output_dir}/{metric name}_vector.csv”. Samples from all repetitions are stored in this file, with a dedicated column for the repetition number. For example:

    sample, timestamp, repetition
0.1, 100, 0
0.2, 200, 0
0.15, 100, 1
[...]

    or, in case of a “dict” metric with custom columns:

    column1, column2, column3, timestamp, repetition
0.1, 0.01, 0.001, 100, 0
0.2, 0.02, 0.004, 200, 0
0.15, 0.015, 0.00225, 100, 1
[...]

    While the simulations are running, some temporary csv files will also be stored in the output directory.

  • repetitions (int), optional:

    The number of independent repetitions to run. Defaults to 1.

  • simulate_until (float or None), optional:

    The time until which the simulation will run. If None, simulation runs as long as there are events. Defaults to None.

  • time_unit (str), optional:

    The time unit for the simulation. Defaults to “us” (microseconds). Other options are “ms” (milliseconds), “ns” (nanoseconds), “s” (seconds).

  • yaml_directory (str), optional:

    The path to the directory containing all other yaml files to set the simulation (see the YAML files documentation). The path is relative to this configuration file directory. Defaults to “./” .