How to prevent logback from outputting its own status at the start of every log when using a layout
This seems like a carelessness error, but I can't seem to find the cause. Logging with logback/slf4j (most recent version slf4j-api-1.6.1, logback core/classic 0.9.24). Simplest log configuration for testing is:
<configuration>
<appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
<layout class="ch.qos.logback.classic.PatternLayout">
<!-- DONT USE THIS FORMATTER FOR LIVE LOGGING THE %L LINE NUMBER OUTPUTTER IS SLOW -->
<pattern>%le %-1r [%c{1}:%L] %m%n</pattern>
</layout>
</appender>
<root level="DEBUG">
<appender-ref ref="stdout" />
</root>
</configuration>
Every log setup starts with logback's internal status lines:
11:21:27,825 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback.groovy]
11:21:27,826 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Found resource [logback-test.xml] at [file:.../logback-test.xml]
11:21:28,116 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - debug attribute not set
11:21:28,124 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender]
11:21:28,129 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [stdout]
11:21:28,180 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Pushing component [layout] on top of the object stack.
11:21:28,206 |-WARN in ch.qos.logback.core.ConsoleAppender[stdout] - This appender no longer admits a layout as a sub-component, set an encoder instead.
11:21:28,206 |-WARN in ch.qos.logback.core.ConsoleAppender[stdout] - To ensure compatibility, wrapping your layout in LayoutWrappingEncoder.
11:21:28,206 |-WARN in ch.qos.logback.core.ConsoleAppender[stdout] - See also http://logback.qos.ch/codes.html#layoutInsteadOfEncoder for details
11:21:28,207 |-INFO in ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level of ROOT logger to DEBUG
11:21:28,207 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [stdout] to Logger[ROOT]
which is, according to the docs, the format logback uses for default. It then finishes reading the config (which is set up to output a different format) and continues with the properly formatted output. There's a config parameter <configuration debug="false"> which does not affect this.
Anyone know how to shut this off?
Answer
If you set the debug attribute of the configuration element to true, you will get all status information to the console. If this is your problem, just set it to false or remove it.
If you have any configuration problems of level WARN or above, you will also get all status information logged to the console (including messages of level INFO). The best solution to this problem is to fix the problem (in your case replace the <layout> element with an <encoder> element).
If you for some reason cannot fix the problem, but want to remove the status-information from the console, you can instead configure an alternative StatusListener. Use the NopStatusListener to completely remove the status-information:
<configuration>
<statusListener class="ch.qos.logback.core.status.NopStatusListener" />
<!-- etc -->
</configuration>