DOMConfigurator.doConfigure(final URL url, LoggerRepository repository) opens the configuration file using the equivalent of url.openConnection().getInputStream()). However, that input stream is never closed. In some situations, when DOMConfigurator.configure(URL) is invoked multiple times, it leads to java.io.FileNotFoundException: log4j.xml (Too many open files (errno:24))
Thanks for the report. Fixed in rev 956283 for log4j and rev 956284 for extras.