Logging parameters and metrics in MLOps - Commands & Configuration

Introduction

When you train a machine learning model, you want to keep track of what settings you used and how well the model performed. Logging parameters and metrics helps you remember these details so you can compare different runs and pick the best model.

When you want to save the learning rate and number of training steps used in a model run.

When you want to record the accuracy or loss of a model after training to see how well it did.

When you want to compare different model versions by their performance numbers.

When you want to keep a history of experiments to avoid repeating the same mistakes.

When you want to share your model results with teammates in a clear, organized way.

Commands

This command installs MLflow, a tool that helps you log parameters and metrics easily during machine learning experiments.

Terminal

pip install mlflow

Expected Output

Collecting mlflow

  Downloading mlflow-2.6.0-py3-none-any.whl (18.3 MB)

Installing collected packages: mlflow

Successfully installed mlflow-2.6.0

This runs a Python script that logs parameters and metrics using MLflow. It shows how to save settings and results for a model training run.

Terminal

python log_params_metrics.py

Expected Output

2024/06/01 12:00:00 INFO mlflow.tracking.fluent: Experiment with name 'Default' does not exist. Creating a new experiment.

2024/06/01 12:00:00 INFO mlflow.tracking.fluent: Experiment created with ID '1'

2024/06/01 12:00:01 INFO mlflow.tracking.fluent: Run with ID '1234567890abcdef' started

2024/06/01 12:00:01 INFO mlflow.tracking.fluent: Logged parameter: learning_rate = 0.01

2024/06/01 12:00:01 INFO mlflow.tracking.fluent: Logged parameter: epochs = 10

2024/06/01 12:00:01 INFO mlflow.tracking.fluent: Logged metric: accuracy = 0.85

2024/06/01 12:00:01 INFO mlflow.tracking.fluent: Run with ID '1234567890abcdef' ended

Key Concept

If you remember nothing else from this pattern, remember: logging parameters and metrics lets you track what you tried and how well it worked so you can improve your models.

Code Example

MLOps

import mlflow

with mlflow.start_run():
    mlflow.log_param("learning_rate", 0.01)
    mlflow.log_param("epochs", 10)
    mlflow.log_metric("accuracy", 0.85)
print("Parameters and metrics logged successfully.")

Common Mistakes

Not starting an MLflow run before logging parameters and metrics.

Without starting a run, MLflow does not know where to save the data, so logging calls fail or data is lost.

Always use mlflow.start_run() as a context manager before logging parameters and metrics.

Logging parameters or metrics with wrong data types, like passing a list instead of a number or string.

MLflow expects parameters as strings or numbers and metrics as numbers; wrong types cause errors.

Convert parameters to strings and metrics to floats or ints before logging.

Summary

Install MLflow to enable logging of parameters and metrics.

Use mlflow.start_run() to begin a logging session.

Log parameters with mlflow.log_param() and metrics with mlflow.log_metric() inside the run.

This process helps track experiment settings and results for better model comparison.

Practice

1.

What is the main purpose of logging parameters in machine learning experiments?

easy

A. To record the settings used during model training

B. To measure the model's accuracy on test data

C. To save the final trained model file

D. To visualize the model's predictions

Solution

1. Step 1: Understand what parameters are

   Parameters are the settings or configurations used to train a model, like learning rate or number of layers.

2. Step 2: Identify the purpose of logging parameters

   Logging parameters helps keep track of these settings so you can compare different training runs.

3. Final Answer:

   To record the settings used during model training -> Option A

4. Quick Check:

   Logging parameters = record training settings [OK]

Hint: Parameters = training settings, metrics = performance [OK]

Common Mistakes:

• Confusing parameters with metrics
• Thinking logging saves the model file
• Assuming logging is for visualization

2.

Which of the following is the correct way to log a metric named accuracy with value 0.95 using a typical MLOps logging function log_metric?

easy

A. log_metric('accuracy', 0.95)

B. log_metric(accuracy=0.95)

C. log_metric('accuracy': 0.95)

D. log_metric(0.95, 'accuracy')

Solution

1. Step 1: Understand typical function syntax

   Logging functions usually take the metric name as a string first, then the value as a number.

2. Step 2: Check each option's syntax

   log_metric('accuracy', 0.95) uses correct syntax: function name, string key, numeric value. log_metric(accuracy=0.95) uses keyword argument which may not be supported. log_metric('accuracy': 0.95) uses invalid syntax with colon inside parentheses. log_metric(0.95, 'accuracy') reverses arguments incorrectly.

3. Final Answer:

   log_metric('accuracy', 0.95) -> Option A

4. Quick Check:

   Function(metric_name, value) = correct syntax [OK]

Hint: Metric name first as string, then value [OK]

Common Mistakes:

• Using colon instead of comma in function call
• Passing arguments in wrong order
• Using keyword arguments when not supported

3.

Given the following code snippet, what will be the output logged for the metric loss?

log_metric('loss', 0.25)
log_metric('loss', 0.20)
log_metric('loss', 0.15)

medium

A. Only the last value 0.15 is logged for 'loss'

B. An error occurs because 'loss' is logged multiple times

C. All three values 0.25, 0.20, and 0.15 are logged separately

D. The first value 0.25 overwrites the others

Solution

1. Step 1: Understand metric logging behavior

   Most MLOps tools allow logging multiple values for the same metric over time to track progress.

2. Step 2: Analyze the code snippet

   The code logs 'loss' three times with different values. Each call records a new metric value, not overwriting previous ones.

3. Final Answer:

   All three values 0.25, 0.20, and 0.15 are logged separately -> Option C

4. Quick Check:

   Multiple logs for same metric = multiple entries [OK]

Hint: Repeated metric logs add entries, not overwrite [OK]

Common Mistakes:

• Assuming repeated logs overwrite previous values
• Expecting an error on duplicate metric names
• Thinking only one value per metric is allowed

4.

Identify the error in this code snippet for logging a parameter batch_size with value 32:

log_param(batch_size, '32')

medium

A. Function name should be log_metric instead of log_param

B. Value should be a number, not a string

C. No error, the code is correct

D. Parameter name should be a string, not a variable

Solution

1. Step 1: Check parameter name argument

   The parameter name must be a string literal like 'batch_size', not a bare variable name.

2. Step 2: Check value argument

   Value can be string or number depending on context; '32' as string is acceptable here.

3. Final Answer:

   Parameter name should be a string, not a variable -> Option D

4. Quick Check:

   Parameter name = string literal [OK]

Hint: Parameter names must be quoted strings [OK]

Common Mistakes:

• Passing parameter name without quotes
• Confusing log_param with log_metric
• Thinking value must always be numeric

5.

You want to log both parameters and metrics for a training run using the following code:

log_param('learning_rate', 0.01)
log_param('optimizer', 'adam')
log_metric('accuracy', 0.92)
log_metric('loss', 0.1)

Which of these statements is true about the logged data?

hard

A. Metrics record model settings; parameters record model performance

B. Parameters record model settings; metrics record model performance

C. Both parameters and metrics record model performance

D. Both parameters and metrics record model settings

Solution

1. Step 1: Understand the role of parameters

   Parameters like learning rate and optimizer are settings used to train the model.

2. Step 2: Understand the role of metrics

   Metrics like accuracy and loss measure how well the model performs after training.

3. Final Answer:

   Parameters record model settings; metrics record model performance -> Option B

4. Quick Check:

   Parameters = settings, Metrics = performance [OK]

Hint: Parameters = settings, metrics = results [OK]

Common Mistakes:

• Mixing up parameters and metrics roles
• Thinking metrics are settings
• Assuming parameters measure performance