Downloading Logs

App Engine maintains a log of messages that your application emits using the logging module from the Python standard library, as well as other messages printed to the standard error stream. App Engine also records each request in the log. Each log severity level (4 for CRITICAL, 3 for ERROR, 2 for WARNING, 1 for INFO, 0 for DEBUG) has a fixed buffer size that controls the amount of log information you can access. Normally, you use logging features more at lower log levels; thus, the time window is smaller for log events at these levels. Each request logged is assigned a request ID, a globally unique identifier based on the request's start time.

To browse your app's logs of the last 90 days, you can also use the Logs page in the Google Cloud console.

Requesting the logs

The appcfg tool is now shut down. The replacement, Google Cloud CLI, does not support the ability to download logs; however, you can view your logs using the gcloud app log commands.