The default timeout value for the Web Admin Console of GlassFish v2 is set to 60 minutes by default.
If you want to change this (some people find it annoying to be disconnect too often and other find one hour to be too long), you can either emit this
% asadmin set server.admin-service.das-config.admin-session-timeout-in-minutes= ...
…or modify the value of
<das-config admin-session-timeout-in-minutes="60" ... in the
domain.xml config file (editing XML by hand isn’t a really good idea).
Make sure you restart your browser for this to take effect (thanks Kedar).
The documentation for this feature is here.
Previous GlassFish tips are here.