Troubleshooting

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Pipeline edit page freezes browser

The data output of a block contains too much information for the browser to render.

To temporarily fix this, open the /terminal page in Mage. Then type the following command press enter to run it:

rm -rf mage_data/[project_name]/pipelines/[pipeline_name]/.variables

The above command will remove the data output files for each block in your pipeline.

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Can’t connect to local database from within Mage via Docker

If you’re running Mage via Docker and you’re trying to connect to a local database outside of Docker, you must use the following host or IP value when trying to connect to it: host.docker.internal.

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Unpredictable Columns in an Upstream Dataframe

Sometimes, upstream data is out of our contol. If we’re expecting a column in a dataframe and writing SQL against it, we might see a SQL compilation error: invalid identifier.

Thankfully, Mage Community member Josh Pachner has a solution.

Say you have an upstream block that looks like:

SELECT 
  df."col_1",
  df."col_2",
  df."col_3",
FROM {{ df }} df

Where the underlying df might all three columns… or just a subset. For example, col_1 isn’t always present.

For cases where expected columns might not in our dataframe, we can add a transformer block upstream of an exporter:

# headers = [cols we need in our dataframe]
# df = our DataFrame()

for head in headers:
  if head not in df.columns:
       df[head] = None

This is especially helpful in databases like Snowflake, which don’t have an iferror() function to check for missing columns.

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InvalidToken error when accessing data in S3

Accessing data located in S3, you may see an error like this:

An error occurred (InvalidToken) when calling the GetObject operation: 
The provided token is malformed or otherwise invalid.

This Stack Overflow article details the issue. Removing the AWS_SESSION_TOKEN line from the io_config.yaml should resolve the problem.

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Mage doesn’t load properly when running locally

When attempting to connect to Mage with a port other than 6789, the browser may not render the page correctly with localhost:port.

Instead, use 127.0.0.1:port to connect to Mage.

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Using credential files in Docker

If you have files containing secret credentials (e.g. GCP credentials JSON files), you’ll need to mount them as a volume so that those files appear in your running Docker container.

Use the -v command in your docker run command to mount the directory containing your files:

docker run -it -p 6789:6789
    -v /Users/dragon/secrets:/home/secrets \
    -v $(pwd):/home/src mageai/mageai \
    /app/run_app.sh mage start [project_name]

or, using docker compose, add a volume mount to your Mage service. The following is an example of mounting the ~/.aws directory for authenticating via the AWS CLI:

services:
  mage:
    image: mageai/mageai:latest
    ...
    volumes:
      - ~/.aws:/root/.aws