---
title: Event Logging
sidebar_position: 9
version: 1
---

# Logging

## Event Logging

Superset by default logs special action events in its internal database (DBEventLogger). These logs can be accessed
on the UI by navigating to **Security > Action Log**. You can freely customize these logs by
implementing your own event log class.
**When custom log class is enabled DBEventLogger is disabled and logs
stop being populated in UI logs view.**
To achieve both, custom log class should extend built-in DBEventLogger log class.

Here's an example of a simple JSON-to-stdout class:

```python
    def log(self, user_id, action, *args, **kwargs):
        records = kwargs.get('records', list())
        dashboard_id = kwargs.get('dashboard_id')
        slice_id = kwargs.get('slice_id')
        duration_ms = kwargs.get('duration_ms')
        referrer = kwargs.get('referrer')

        for record in records:
            log = dict(
                action=action,
                json=record,
                dashboard_id=dashboard_id,
                slice_id=slice_id,
                duration_ms=duration_ms,
                referrer=referrer,
                user_id=user_id
            )
            print(json.dumps(log))
```

End by updating your config to pass in an instance of the logger you want to use:

```
EVENT_LOGGER = JSONStdOutEventLogger()
```

## StatsD Logging

Superset can be configured to log events to [StatsD](https://github.com/statsd/statsd)
if desired. Most endpoints hit are logged as
well as key events like query start and end in SQL Lab.

Superset can also collect gunicorn [metrics](https://gunicorn.org/instrumentation/).
To enable these, the following environment variables should be set:

```bash
SERVER_STATSD_HOST=localhost
SERVER_STATSD_PORT=8125
SERVER_STATSD_PREFIX=superset
```

To setup StatsD logging for Superset, it’s a matter of configuring the logger in your `superset_config.py`.

```python
import os
from superset.stats_logger import StatsdStatsLogger

try:
    STATSD_PORT = int(os.environ.get("SERVER_STATSD_PORT", "8125"))
except ValueError:
    STATSD_PORT = 8125

STATS_LOGGER = StatsdStatsLogger(
    host=os.environ.get("SERVER_STATSD_HOST", "localhost"),
    port=STATSD_PORT,
    prefix=os.environ.get("SERVER_STATSD_PREFIX", "superset"),
)
```

[statsd](https://pypi.org/project/statsd/) in version ~3.3.0 must be installed.

Note that it’s also possible to implement your own logger by deriving
`superset.stats_logger.BaseStatsLogger`.