General Information



Graphs and Logs

GIT and Storage

Also, see Git is not well-supported in Jupyter...

Remote Debugging (Trains PyCharm Plugin)



Trains Configuration

Trains Server Deployment

Trains Server Configuration

Trains Server Troubleshooting

Trains API

General Information

How do I know a new version came out?

Starting with Trains v0.9.3, Trains issues a new version release notification, which appears in the log and is output to the console, if a Python experiment script is run.

For example, when a new Trains Python Client package version is available, the notification is:

TRAINS new package available: UPGRADE to vX.Y.Z is recommended!

When a new Trains Server version is available, the notification is:

TRAINS-SERVER new version available: upgrade to vX.Y is recommended!


How can I sort models by a certain metric?

Trains associates models with the experiments that created them. To sort experiments by a metric, in the Trains Web-App (UI), add a custom column in the experiments table and sort by that metric column.

Can I store more information on the models?

Yes! For example, you can use the Task.set_model_label_enumeration method to store class enumeration:

Task.current_task().set_model_label_enumeration( {"label": int(0), } )

For more information about Task class methods, see the Task Class reference page.

Can I store the model configuration file as well?

Yes! Use the Task.set_model_config method:

Task.current_task().set_model_config("a very long text with the configuration file's content")

I am training multiple models at the same time, but I only see one of them. What happened?

Currently, in the experiment info panel, Trains shows only the last associated model. In Trains Web-App (UI), on the Projects page, the Models tab shows all models.

This will be improved in a future version.

Can I log input and output models manually?

Yes! Use the InputModel.import_model method and Task.connect methods to manually connect an input model. Use the Task.update_weights method to manually connect a model weights file.

input_model = InputModel.import_model(link_to_initial_model_file)


For more information about models, see InputModel and OutputModel classes.


I noticed I keep getting the message "warning: uncommitted code". What does it mean?

This message is only a warning. Trains not only detects your current repository and git commit, but also warns you if you are using uncommitted code. Trains does this because uncommitted code means this experiment will be difficult to reproduce. You can see uncommitted changes in the Trains Web-App (UI), experiment info panel, EXECUTION tab.

I do not use argparse for hyperparameters. Do you have a solution?

Yes! Trains supports connecting hyperparameter dictionaries to experiments using the Task.connect method.

For example, to log the hyperparameters learning_rate, batch_size, display_step, model_path, n_hidden_1, and n_hidden_2:

# Create a dictionary of parameters
parameters_dict = { 'learning_rate': 0.001, 'batch_size': 100, 'display_step': 1, 
    'model_path': "/tmp/model.ckpt", 'n_hidden_1': 256, 'n_hidden_2': 256 }

# Connect the dictionary to your TRAINS Task
parameters_dict = Task.current_task().connect(parameters_dict)

I noticed that all of my experiments appear as "Training" Are there other options?

Yes! When creating experiments and calling Task.init, you can provide an experiment type. Trains supports multiple experiment types. For example:

task = Task.init(project_name, task_name, Task.TaskTypes.testing)

Sometimes I see experiments as running when in fact they are not. What's going on?

Trains monitors your Python process. When the process exits properly, Trains closes the experiment. When the process crashes and terminates abnormally, it sometimes misses the stop signal. In this case, you can safely right click the experiment in the Web-App and abort it.

My code throws an exception, but my experiment status is not "Failed". What happened?

This issue was resolved in v0.9.2. Upgrade Trains by executing the following command:

pip install -U trains

When I run my experiment, I get an SSL Connection error CERTIFICATE_VERIFY_FAILED. Do you have a solution?

Your firewall may be preventing the connection. Try one of the following solutions:

  • Direct python "requests" to use the enterprise certificate file by setting the OS environment variables CURL_CA_BUNDLE or REQUESTS_CA_BUNDLE. For a detailed discussion of this topic, see https://stackoverflow.com/questions/48391750/disable-python-requests-ssl-validation-for-an-imported-module.
  • Disable certificate verification (for security reasons, this is not recommended):

    1. Upgrade Trains to the current version:

      pip install -U trains
    2. Create a new trains.conf configuration file (see a sample trains.conf), containing:

      api { verify_certificate = False }
    3. Copy the new trains.conf file to ~/trains.conf (on Windows: C:\Users\your_username\trains.conf)

How do I modify experiment names once they have been created?

An experiment's name is a user-controlled property which can be accessed via the Task.name variable. This allows you to use meaningful naming schemes for easily filtering and comparing of experiments.

For example, to distinguish between different experiments, you can append the task ID to the task name:

task = Task.init('examples', 'train')
task.name += ' {}'.format(task.id)

Or, append the Task ID post-execution:

tasks = Task.get_tasks(project_name='examples', task_name='train')
for t in tasks:
    t.name += ' {}'.format(task.id)

Another example is to append a specific hyperparameter and its value to each task's name:

tasks = Task.get_tasks(project_name='examples', task_name='my_automl_experiment')
for t in tasks:
    params = t.get_parameters()
    if 'my_secret_parameter' in params:
        t.name += ' my_secret_parameter={}'.format(params['my_secret_parameter'])

Use this experiment naming when creating automation pipelines with a naming convention.

Using Conda and the "typing" package, I get the error "AttributeError: type object 'Callable' has no attribute '_abc_registry'". How do I fix this?

Conda and the typing package may have some compatibility issues.

However, since Python 3.5, the typing package is part of the standard library.

To resolve the error, uninstall typing and rerun you script. If this does not fix the issue, create a new Trains issue, including the full error, and your environment details.

My Trains Server disk space usage is too high. What can I do about this?

We designed the Trains open source suite, including Trains Server, to ensure experiment traceability. For this reason, the Trains Web-App (UI) does not include a feature to delete experiments. The Trains Web-App (UI) does allow you to archive experiments so that they appear only in the Archive area.

In rare instances, however, such as high disk usage for a self-hosted Trains Server because Elasticsearch is indexing unwanted experiments, you may choose to delete an experiment.

You can use the APIClient provided by Trains Agent and client.tasks.delete() to delete an experiment.

You cannot restore a deleted experiment.

You cannot undo the deletion of an experiment.

For example, the following script deletes an experiment whose Task ID is 123456789.

from trains_agent import APIClient

client = APIClient()

Can I change the random seed my experiment uses?

Yes! By default, Trains initializes Tasks with a default seed. You change that seed by calling the make_deterministic method.

In the Web UI, I can't access files that my experiment stored. Why not?

Trains stores file locations. The machine running your browser must have access to the location where the machine which ran the Task stored the file. This applies to debug samples and artifacts. If, for example, the machine running the browser does not have access, you may see "Unable to load image", instead of the image.

I get the message "TRAINS Monitor: Could not detect iteration reporting, falling back to iterations as seconds-from-start". What does it mean?

If metrics reporting begins within the first three minutes, Trains reports resource monitoring by iteration. Otherwise, it reports resource monitoring by seconds from start, and logs a message, "TRAINS Monitor: Could not detect iteration reporting, falling back to iterations as seconds-from-start".

However, if metrics reporting begins after three minutes and anytime up to thirty minutes, resource monitoring reverts to by iteration, and Trains logs a message "TRAINS Monitor: Reporting detected, reverting back to iteration based reporting". After thirty minutes, it remains unchanged.

Graphs and Logs

The first log lines are missing from the experiment log tab. Where did they go?

Due to speed/optimization issues, we opted to display only the last several hundred log lines.

You can always downloaded the full log as a file using the Trains Web-App (UI). In Trains Web-App (UI), the experiment info panel, RESULTS tab, LOG sub-tab, use the download full log feature.

Can I create a graph comparing hyperparameters vs model accuracy?

Yes! You can manually create a plot with a single point X-axis for the hyperparameter value, and Y-Axis for the accuracy. For example:

number_layers = 10
accuracy = 0.95
    "performance", "accuracy", iteration=0, 
    mode='markers', scatter=[(number_layers, accuracy)])

Assuming the hyperparameter is number_layers with current value 10, and the accuracy for the trained model is 0.95. Then, the experiment comparison graph shows:


Another option is a histogram chart:

number_layers = 10
accuracy = 0.95
    "performance", "accuracy", iteration=0, labels=['accuracy'],
    values=[accuracy], xlabels=['number_layers %d' % number_layers])


I want to add more graphs, not just with TensorBoard. Is this supported?

Yes! The Logger module includes methods for explicit reporting. For examples of explicit reporting, see our Explicit Reporting tutorial, which includes a list of methods for explicit reporting.

How can I report more than one scatter 2D series on the same plot?

The Logger.report_scatter2d() method reports all series with the same title and iteration parameter values on the same plot.

For example, the following two scatter2D series are reported on the same plot, because both have a title of example_scatter and an iteration of 1:

scatter2d_1 = np.hstack((np.atleast_2d(np.arange(0, 10)).T, np.random.randint(10, size=(10, 1))))
logger.report_scatter2d("example_scatter", "series_1", iteration=1, scatter=scatter2d_1,
                        xaxis="title x", yaxis="title y")

scatter2d_2 = np.hstack((np.atleast_2d(np.arange(0, 10)).T, np.random.randint(10, size=(10, 1))))
logger.report_scatter2d("example_scatter", "series_2", iteration=1, scatter=scatter2d_2,
                        xaxis="title x", yaxis="title y")

GIT and Storage

Is there something Trains can do about uncommitted code running?

Yes! Trains stores the git diff as part of the experiment's information. You can view the git diff in the Trains Web-App (UI), experiment info panel, EXECUTION tab.

I read there is a feature for centralized model storage. How do I use it?

When calling Task.init, providing the output_uri parameter allows you to specify the location in which model checkpoints (snapshots) will be stored.

For example, to store model checkpoints (snapshots) in /mnt/shared/folder:

task = Task.init(project_name, task_name, output_uri="/mnt/shared/folder")

Trains will copy all stored snapshots into a subfolder under /mnt/shared/folder. The subfolder's name will contain the experiment's ID. If the experiment's ID is 6ea4f0b56d994320a713aeaf13a86d9d, the following folder will be used:


Trains supports other storage types for output_uri, including:

# AWS S3 bucket
task = Task.init(project_name, task_name, output_uri="s3://bucket-name/folder")

# Google Cloud Storage bucket
task = Task.init(project_name, task_name, output_uri="gs://bucket-name/folder")

To use Cloud storage with Trains, configure the storage credentials in your ~/trains.conf. For detailed information, see Trains Configuration Reference.

When using PyCharm to remotely debug a machine, the Git repo is not detected. Do you have a solution?

Yes! Since this is such a common occurrence, we created a PyCharm plugin that allows a remote debugger to grab your local repository / commit ID. For detailed information about using our plugin, see the Trains PyCharm Plugin on the "Trains Plugins" page.


I am using Jupyter Notebook. Is this supported?

Yes! You can run Trains in Jupyter Notebooks using either of the following:

  • Option 1: Install Trains on your Jupyter Notebook host machine
  • Option 2: Install Trains in your Jupyter Notebook and connect using Trains credentials

Option 1: Install Trains on your Jupyter host machine

  1. Connect to your Jupyter host machine.
  2. Install the Trains Python Client package.

    pip install trains
  3. Run the Trains initialize wizard.

  4. In your Jupyter Notebook, you can now use Trains.

Option 2: Install Trains in your Jupyter Notebook

  1. In the Trains Web-App (UI), Profile page, create credentials and copy your access key and secret key. These are required in the Step 3.

  2. Install the Trains Python Client package.

    pip install trains
  3. Use the Task.set_credentials method to specify the host, port, access key and secret key (see step 1).

    # Set your credentials using the trains apiserver URI and port, access_key, and secret_key.
    Task.set_credentials(host='http://localhost:8008',key='<access_key>', secret='<secret_key>')

    Host is the API server

    host is the API server (default port 8008), not the web server (default port 8080).

  4. You can now use Trains.

    # create a task and start training
    task = Task.init('juptyer project', 'my notebook')

Git is not well-supported in Jupyter, so we just gave up on committing our code. Do you have a solution?

Yes! Use our Trains Jupyter Plugin. This plugin allows you to commit your notebook directly from Jupyter. It also saves the Python version of your code and creates an updated requirements.txt, so you know which packages you were using.

Remote Debugging (Trains PyCharm Plugin)

I am using your Trains PyCharm Plugin for remote debugging. I get the message "trains.Task - INFO - Repository and package analysis timed out (10.0 sec), giving up". What should I do?

Trains uses a background thread to analyze the script. This includes package requirements. At the end of the execution of the script, if the background thread is still running, Trains allows the thread another 10 seconds to complete. If the thread does not complete, it times out.

This can occur for scripts that do not import any packages, for example short test scripts.

To fix this issue, you could import the time package and add a time.sleep(20) statement to the end of your script.


Can I use Trains with scikit-learn?

Yes! scikit-learn is supported. Everything you do is logged. Trains automatically logs models which are stored using joblib. See the scikit-learn examples.

Trains Configuration

How do I explicitly specify the Trains configuration file to be used?

To override the default configuration file location, set the TRAINS_CONFIG_FILE OS environment variable.

For example:

export TRAINS_CONFIG_FILE="/home/user/mytrains.conf"

How can I override Trains credentials from the OS environment?

To override your configuration file / defaults, set the following OS environment variables:

export TRAINS_API_ACCESS_KEY="key_here"
export TRAINS_API_SECRET_KEY="secret_here"
export TRAINS_API_HOST="http://localhost:8008"

How can I track OS environment variables with experiments?

Set the OS environment variable TRAINS_LOG_ENVIRONMENT with the variables you need track, either:

  • All environment variables:

  • Specific environment variables, for example, log PWD and PYTHONPATH:

  • No environment variables:


Trains Server Deployment

How do I deploy Trains Server on stand-alone Linux Ubuntu or macOS systems?

For detailed instructions, see Deploying Trains Server: Linux or macOS in the "Deploying Trains" section.

How do I deploy Trains Server on Windows 10?

For detailed instructions, see Deploying Trains Server: Windows 10 in the "Deploying Trains" section.

How do I deploy Trains Server on AWS EC2 AMIs?

For detailed instructions, see Deploying Trains Server: AWS EC2 AMIs in the "Deploying Trains" section.

How do I deploy Trains Server on the Google Cloud Platform?

For detailed instructions, see Deploying Trains Server: Google Cloud Platform in the "Deploying Trains" section.

How do I restart Trains Server?

For detailed instructions, see the "Restarting" section of our documentation page for your deployment format. For example, if you deployed to Linux, see Restarting on the "Deploying Trains Server: Linux or macOS" page.

Can I deploy Trains Server on Kubernetes clusters?

Yes! Trains Server supports Kubernetes. For detailed instructions, see Deploying Trains Server: Kubernetes in the "Deploying Trains" section.

Can I create a Helm Chart for Trains Server Kubernetes deployment?

Yes! You can create a Helm Chart of Trains Server Kubernetes deployment.

For detailed instructions, see Deploying Trains Server: Kubernetes using Helm in the "Deploying Trains" section.

My Docker cannot load a local host directory on SELinux?

If you are using SELinux, run the following command (see this discussion):

chcon -Rt svirt_sandbox_file_t /opt/trains

Trains Server Configuration

How do I configure Trains Server for sub-domains and load balancers?

For detailed instructions, see Configuring Sub-domains and load balancers on the "Configuring Trains Server" page.

Can I add web login authentication to Trains Server?

By default, anyone can login to the Trains Server Web-App. You can configure the Trains Server to allow only a specific set of users to access the system.

For detailed instructions, see Configuring Web Login Authentication on the "Configuring Trains Server" page in the "Deploying Trains" section.

Can I modify a non-responsive task settings?

The non-responsive experiment watchdog monitors experiments that were not updated for a specified time interval and marks them as aborted. The watchdog is always active.

You can modify the following settings for the watchdog:

  • The time threshold (in seconds) of task inactivity (default value is 7200 seconds which is 2 hours).
  • The time interval (in seconds) between watchdog cycles.

For detailed instructions, see Modifying non-responsive Task watchdog settings on the "Configuring Trains Server" page.

Trains Server Troubleshooting

How do I fix Docker upgrade errors?

To resolve the Docker error:

... The container name "/trains-???" is already in use by ...

try removing deprecated images:

$ docker rm -f $(docker ps -a -q)

Why is web login authentication not working?

A port conflict between the Trains Server MongoDB and / or Elastic instances, and other instances running on your system may prevent web login authentication from working correctly.

Trains Server uses the following default ports which may be in conflict with other instances:

  • MongoDB port 27017
  • Elastic port 9200

You can check for port conflicts in the logs in /opt/trains/log.

If a port conflict occurs, change the MongoDB and / or Elastic ports in the docker-compose.yml, and then run the Docker compose commands to restart the Trains Server instance.

To change the MongoDB and / or Elastic ports for your Trains Server, do the following:

  1. Edit the docker-compose.yml file.
  2. In the services/trainsserver/environment section, add the following environment variable(s):

    • For MongoDB:

      MONGODB_SERVICE_PORT: <new-mongodb-port>
    • For Elastic:

      ELASTIC_SERVICE_PORT: <new-elasticsearch-port>

      For example:

  3. For MongoDB, in the services/mongo/ports section, expose the new MongoDB port:

    For example:
  4. For Elastic, in the services/elasticsearch/ports section, expose the new Elastic port:


    For example:

  5. Restart Trains Server, see Restarting Trains Server.\

How do I bypass a proxy configuration to access my local Trains Server?

A proxy server may block access to Trains Server configured for localhost.

To fix this, you may allow bypassing of your proxy server to localhost using a system environment variable, and configure Trains for Trains Server using it.

Do the following:

  1. Allow bypassing of your proxy server to localhost using a system environment variable, for example:

    NO_PROXY = localhost
  2. If a Trains configuration file (trains.conf) exists, delete it.

  3. Open a terminal session.
  4. In the terminal session, set the system environment variable to, for example:

    • Linux:

    • Windows:

      set no_proxy=
      set NO_PROXY=
  5. Run the Trains wizard trains-init to configure Trains for Trains Server, which will prompt you to open the Trains Web-App (UI) at,, and create new Trains credentials.

    The wizard completes with:

    Verifying credentials ...
    Credentials verified!
    New configuration stored in /home/<username>/trains.conf
    TRAINS setup completed successfully.

Trains is failing to update Trains Server. I get an error 500 (or 400). How do I fix this?

A failure to update Trains Server (error 500, or possibly error 400) can indicate low free disk space, and the Elasticsearch service used by your server may have gone into read-only mode. This can happen if the percentage of disk space used reaches an Elasticsearch watermark (by default, the Elasticsearch low watermark is 85% disk space used, and the high watermark is 90% disk space used).

You may fix this by either freeing up space on the disk, or if it is an AWS EC2 instance (or similar alternative), increase the allocated disk space.

The Trains error or warning message

The message logged by Trains may include "[FORBIDDEN/12/index read-only / allow delete (api)]".

Trains API

How can I use the Trains API to fetch data?

To fetch data using the Trains API, create an authenticated session and send requests for data using the Trains API services and methods. The responses to the requests contain your data.

For example, to get the metrics for an experiment and print metrics as a histogram:

  1. Start an authenticated session.
  2. Send a request for all projects named examples using the projects service GetAllRequest method.
  3. From the response, get the Ids of all those projects named examples.
  4. Send a request for all experiments (tasks) with those project Ids using the tasks service GetAllRequest method.
  5. From the response, get the data for the experiment (task) ID 11 and print the experiment name.
  6. Send a request for a metrics histogram for experiment (task) ID 11 using the events service ScalarMetricsIterHistogramRequest method and print the histogram.
    # Import Session from the trains backend_api
    from trains.backend_api import Session
    # Import the services for tasks, events, and projects
    from trains.backend_api.services import tasks, events, projects
    # Create an authenticated session
    session = Session()
    # Get projects matching the project name 'examples'
    res = session.send(projects.GetAllRequest(name='examples'))
    # Get all the project Ids matching the project name 'examples"
    projects_id = [p.id for p in res.response.projects]
    print('project ids: {}'.format(projects_id))
    # Get all the experiments/tasks
    res = session.send(tasks.GetAllRequest(project=projects_id))
    # Do your work
    # For example, get the experiment whose ID is '11'
    task = res.response.tasks[11]
    print('task name: {}'.format(task.name))
    # For example, for experiment ID '11', get the experiment metric values
    res = session.send(events.ScalarMetricsIterHistogramRequest(
    scalars = res.response_data
    print('scalars {}'.format(scalars))