###### Pipelines -> IPythonHandler -> Tornado.log -> lib/logging
##### When to add log messages Use INFO level for routines(functions), like when handling requests or state changes and DEBUG for troubleshooting and diagnostics.
``` def foo (arg): self.debug.info(f"doing something with this {arg}") do something with arg self.log.info(f"Result of arg is ... {result}") ``` Use WARNING level when it is important, but not an error, for example, when a user attempts to login with an incorrect password
``` def authenticate(username, password): if username and password doesn't work: self.log.warn(f"Failed login attempt from {username} : {password}") ``` Use ERROR level when something is actually wrong, like when an exception is thrown, IO operation failure or connectivity issue (e.g. Minio client cant connect to endpoint)
``` try: if not minio_client.bucket_exists(bucket_name): minio_client.make_bucket(bucket_name) except ResponseError: self.log.error("Minio error", exc_info=True) ``` ##### Adding log messages Add log messages by inserting statements as follows:
`self.log.debug("insert debug message", *args, *kwargs)`
Use the appropriate logging levels when inserting specific messages e.g. log.debug, log.warn etc.
The log output will be color coded, legend as follows:
| Log Level | Color |
|-----------|-------|
| DEBUG | Blue |
| INFO | Green |
| WARNING | Yellow |
| ERROR | Red |
| CRITICAL | Magenta |
##### Setting the Log Level
The default Log Level is set to INFO. If you need to increase log verbosity, you can start Jupyterlab with
the `--debug` option for example:
```
jupyter lab --debug