in reply to memory leakage
in thread memory usage and leakage

So if I understand correctly this means the Net::XMPP::Client is leaking memory? How could I better check it?

Well, Net::XMPP::Client or one of the modules it uses -- to narrow it down you might try Devel::Cycle, Devel::Leak, Devel::MemoryTrace::Light, Devel::LeakGuard::Object, Devel::Monitor, but its a lot of T.I.T.S. :)

In Section Seekers of Perl Wisdom