Google App Engine - Can not find my logging messages

Question

I can not find the results of my logging calls. To log messages I tried both:

System.out.println(\"some message\"); 

and

Answer 1

Problem has shrunk into more concrete form - App Engine "eats" info-messages, but shows others, such as error and warning messages.

After this call I have eventually seen my info messages:

log.setLevel(Level.INFO);

But it is still not clearly - why info-messages weren't being shown. Google's manual states:

Everything the servlet writes to the standard output stream (System.out) and standard error stream (System.err) is captured by App Engine and recorded in the application logs. Lines written to the standard output stream are logged at the "INFO" level, and lines written to the standard error stream are logged at the "WARNING" level.