From: Jonathan Rajotte Date: Thu, 26 May 2016 22:05:12 +0000 (-0400) Subject: Fix: log4j example: set logger level to prevent unexpected level inheritance X-Git-Tag: v2.8.1~14 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=0cd1695fc2d07d8b7d4335a58e74fb3bc7aef329;p=lttng-ust.git Fix: log4j example: set logger level to prevent unexpected level inheritance BSF or other jars can ship with log4j.properties file embedded. This causes problem when launching application with a general class path (e.g /usr/share/java/*) since log4j will look for a property file in all loaded jars. If any contains directive for the root logger it will affect any logger with no level who are directly under the root logger. This could result in an unexpected behaviour (e.g no events triggered etc.). Link: https://issues.apache.org/jira/browse/BSF-24 Signed-off-by: Jonathan Rajotte Signed-off-by: Mathieu Desnoyers --- diff --git a/doc/examples/java-log4j/Hello.java b/doc/examples/java-log4j/Hello.java index a477e334..2f1119c0 100644 --- a/doc/examples/java-log4j/Hello.java +++ b/doc/examples/java-log4j/Hello.java @@ -26,6 +26,7 @@ import java.io.IOException; import org.apache.log4j.Appender; import org.apache.log4j.BasicConfigurator; import org.apache.log4j.Logger; +import org.apache.log4j.Level; import org.lttng.ust.agent.log4j.LttngLogAppender; /** @@ -64,6 +65,17 @@ public class Hello { * command line. */ public static void main(String args[]) throws IOException { + + /* + * Set lowest level to make sure all event levels are logged. + * Any jar can override the default log4j rootLogger level + * and a logger with no explicit level defaults to the non-null + * parent level. Events could be ignored if the inherited value + * is to low. + * e.g BSF -> https://issues.apache.org/jira/browse/BSF-24 + */ + HELLO_LOG.setLevel(Level.ALL); + /* Start with the default Log4j configuration, which logs to console */ BasicConfigurator.configure();