Although I've been playing with App Engine for quite a few weeks now, I only found out yesterday how I can download the logs from App Engine for parsing locally. There's no export option in the dashboard, nor any option in the Windows launcher. However, you can do this yourself with appcfg.py.
If, like me, you've only used the launcher up until now, and never done anything with Python outside of GAE, you might find the thought of running python scripts a little scary. Don't worry, it actually turns out to be very easy. I'm hoping when you installed the Launcher you ticked the "Add to PATH" option... :o)
The command you want to run looks something like this:
You should replace "appname" with the name of your app. This is the folder the contains the app.yaml file for the app you wish to get logs for. That means you need to be in the correct directory (or provide a full path). Output.txt is obviously where the logs should be written.
This command will retrieve everything from the last day. This might not be what you want, so you can increase this with the num_days argument.
Note that you can also specify 0 to get all logs:
And finally, if you want all logs that you haven't already downloaded, you can use --append, which will scan the last line of the existing file, and download anything since:
However, you'll find this doesn't work on Windows, and you'll end up with a load of duplicate entries. This is in the bugtracker, but I don't know if/when it'll be fixed. For now, I'm having to just download everything (and I'm not sure if this is counting towards my bandwidth quota!).
Another option worth noting, is include_vhost, which will include the hostname used, so you can seperate requests for different versions of your app (or different custom domains). You can use this like so:
And that's all there is to it. Now you can create nice pretty charts in Microsoft Excel (since Google Spreadsheets sucks!) showing how well (or badly, in my case) your app is doing!