App Engine Java log messages missing

[John Pallister]

Hello list,

After finally getting my "Hello World" web app working in the App Engine development server I've uploaded it to the cloud and immediately struck problems.

The main problem is that I'm not seeing my java.util.logging.Logger log messages (from either my Java or Lisp code) in the App Engine console. I've set ".level=FINER" in my logging.properties file but I don't see any of the messages I see using the development server, apart from a single INFO-level message saying "Startup completed in -0.001 seconds.", sent to stdout.

The other message I do see is an exception from my code, which suggests that either the servlet's init method hasn't been called or it couldn't read the context-param values from the web.xml file (via GenericServlet.getInitParameter()). I wondered whether I should've used system-properties in my appengine-web.xml file instead of context-param elements in web.xml; I'm now checking both, to no apparent effect. But I could debug this if I had my log messages.

In the same log message as the exception there is also the text "javax.servlet.ServletContext log: unavailable" which must be a clue, but Google doesn't throw up any obvious leads for it.

I have added a dirt-simple "Hello World" servlet to my application that calls log.severe() and log.info() to try and get any log messages to appear in the Google Cloud Platform Console Log Viewer (or the legacy AppEngine Log Viewer). On running this I don't get the "log: unavailable" message but I don't get any log messages either.

I can't help the feeling I'm missing something obvious; as I said, this all works fine in the development server (I'm using Java 7 on OS X 10.9). Where do people go to see their Java log messages in the Google Cloud Platform Console?

Cheers,

John :^P

[John Pallister]

OK, I've figured out my logging problem. The Oracle Java 7 docs say[1] to use Logger.getGlobal() but the Google java-docs-samples code uses Logger.getLogger(ClassName.class.getName()). I was using the former which fails silently. It would be nice if this was documented somewhere, or if any of the code snippets in the documentation actually used log messages. Cheers, John :^P [1] https://docs.oracle.com/javase/7/docs/api/java/util/logging/Logger.html#global

[Nicholas (Google Cloud Support)]

Thank you for noting that the use of Logger.getGlobal() fails silently and for posting your findings publicly. I would also suggest that you click the 'Send feedback' link in the top right corner of the documentation you are referring to mentioning how this differs from Oracle's documentation or requesting that our code snippets include examples using Logger.getLogger(...).

Cheers,