How do I write messages to the output log on AWS Glue?

Question

AWS Glue jobs log output and errors to two different CloudWatch logs, /aws-glue/jobs/error and /aws-glue/jobs/output by default. When I include print() statements in my scripts for debugging, they get written to the error log (/aws-glue/jobs/error).

I have tried using:

log4jLogger = sparkContext._jvm.org.apache.log4j  log = log4jLogger.LogManager.getLogger(__name__)  log.warn("Hello World!") 

but "Hello World!" doesn't show up in either of the logs for the test job I ran.

Does anyone know how to go about writing debug log statements to the output log (/aws-glue/jobs/output)?

TIA!

EDIT:

It turns out the above actually does work. What was happening was that I was running the job in the AWS Glue Script editor window which captures Command-F key combinations and only searches in the current script. So when I tried to search within the page for the logging output it seemed as if it hadn't been logged.

NOTE: I did discover through testing the first responder's suggestion that AWS Glue scripts don't seem to output any log message with a level less than WARN!

Answer 1

Try to use built-in python logger from logging module, by default it writes messages to standard output stream.

import logging  MSG_FORMAT = '%(asctime)s %(levelname)s %(name)s: %(message)s' DATETIME_FORMAT = '%Y-%m-%d %H:%M:%S' logging.basicConfig(format=MSG_FORMAT, datefmt=DATETIME_FORMAT) logger = logging.getLogger(<logger-name-here>)  logger.setLevel(logging.INFO)  ...  logger.info("Test log message") 

Answer 2

I know the article is not new but maybe it could be helpful for someone: For me logging in glue works with the following lines of code:

# create glue context glueContext = GlueContext(sc) # set custom logging on logger = glueContext.get_logger() ... #write into the log file with: logger.info("s3_key:" + your_value)