How to configure Log4J2 - java

I have spent a couple hours now trying to figure this out and am at a complete loss. I find the new configuration process unnecessarily complex.
I have a Servlet with a web.xml file with the following:
<context-param>
<param-name>log4jConfiguration</param-name>
<param-value>file:///etc/myApp/log4j2.xml</param-value>
</context-param>
It doesn't seem to have any effect. I am using Tomcat 7.0.42, and I have removed all references to log4j*.jar in the catalina.properties file. The logs in my app are still being sent, but they are just being sent to System.out with none of the formatting I specified.
So, I tried to just do it by hand on my own:
InputStream in =
new FileInputStream(new File("/etc/myApp/log4j2.xml"));
ConfigurationSource source = new ConfigurationSource(in);
ConfigurationFactory factory = new XMLConfigurationFactory();
Configuration configuration = factory.getConfiguration(source);
LoggerContext context = (LoggerContext) LogManager.getContext();
context.start(configuration);
context.updateLoggers();
Logger.getLogger("Test").log(Level.INFO, "This is a logging message.");
First, this seems entirely convoluted. Clearly there exists some code that will search for different files and assume file types based on their extensions via the "log4jConfiguration" property, so why isn't there a LogManger.reconfigure(String) that has the same effect?
Second, this has no effect either. Again, the log is printed to System.out, and none of the requested formatting is being done.
Here is the contents of my log4j2.xml:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="DEBUG">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<File name="LogFile" fileName="/var/log/myApp/myApp.log">
<PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} %p %c{1.} [%t] %m%n"/>
</File>
</Appenders>
<Loggers>
<Root level="DEBUG">
<AppenderRef ref="Console" level="DEBUG"/>
<AppenderRef ref="LogFile" level="DEBUG"/>
</Root>
</Loggers>
</Configuration>
The output in both cases comes out something like:
Dec 03, 2013 6:06:45 PM test.Test main
INFO: This is a logging message.
Thanks in advance,
John
EDIT: This is actually working. It appears that I was missing, "log4j-jcl-2.0-beta9.jar". Remko Popma's answer works as well, if the "context-param" above is not working.

There are many possible scenarios with webapp logging, which makes configuration more complex than the ideal. Putting the log4j2 jars and the config file in your webapp's classpath should work. Did you see the manual page for log4j2 use in web apps? If the issue remains, please file a log4j2 jira ticket.

The LoggerContextalready has a method setConfigLocation that takes in a URI as parameter. It baffles me why there isn't a similar method that takes an InputStream as parameter. Instead we have to deal with the most convoluted and messy way of loading our log4j2.xml that is not on the classpath.

Related

How can I specify a specific format for each Log4j log level

First time trying to use log4j version log4j-1.2.17.jar.
On an existing application the client has log4j in place and there is a log4j.properties file which specifies a light log output. What I want to do is depending on the log level (ERROR & WARN) output a more refined entry.
On the log4j site I came across this but I think it is to be in some .xml file. I need some assistance in understanding how I can put in place the formatting option to alter based on log level.
You don't need to declare separate loggers to achieve this. You can set the logging level on the AppenderRef element.
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
<Appenders>
<File name="file" fileName="app.log">
<PatternLayout>
<Pattern>%d %p %c{1.} [%t] %m %ex%n</Pattern>
</PatternLayout>
</File>
<Console name="STDOUT" target="SYSTEM_OUT">
<PatternLayout pattern="%m%n"/>
</Console>
</Appenders>
<Loggers>
<Root level="trace">
<AppenderRef ref="file" level="DEBUG"/>
<AppenderRef ref="STDOUT" level="INFO"/>
</Root>
</Loggers>
</Configuration>
Would I put this xml content into the web.xml file or another file?
a) If another file what file name and where would it go?
How do I get log4j to realize that I need it to use the xml file?
Will the use of the xml ignore the log4j.properties file?
I know it is a lot of questions but there is only me on the project and the client has a production crisis that needs to be figured out today so I don't have time to go off to read and do tutorials with the client calling me every hour. I figured it may help to get this logging more useful. As the logs are right now I have a date and message output to the log but no idea where the entries are created from without doing extensive searches through the code.
You could do this by defining multiple non-additive Loggers so that the first one only logs errors, the next one warnings and the final one infos and debug.

Log4j 2 - Deactivate drools logger

I am using Log4j 2 and I am unsuccessfully trying to change the logging level of jBPM/Drools, having it as a reference. The drools class that keeps logging is ExtensibleXmlParser.
<?xml version="1.0" encoding="UTF-8"?>
<Configuration>
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
</Console>
</Appenders>
<Loggers>
<Root level="debug">
<AppenderRef ref="Console" />
</Root>
<Logger name="org.drools.core.xml.ExtensibleXmlParser" level="off">
<AppenderRef ref="Console" />
</Logger>
</Loggers>
</Configuration>
If I get it right, ExtensibleXmlParser uses slf4j and Log4j is compatible with sl4j.
Why doesn't this Log4j configuration work? Could someone provide me a working configuration? Should I configure jBPM/Drools logger indendently?
When log4j seems to ignore your tweaks to the log4j.properties/xml file, it most often means you're not fiddling with the right file. It is likely that there is another configuration file in your classpath that gets found earlier and is taken into account.
Search your entire classpath for log4j* pattern and see what comes out (include the contents of .jar files and application server /lib and /ext folders, if any).
If I get it right, ExtensibleXmlParser uses slf4j and Log4j is compatible with sl4j.
"Is compatible" is not equivalent with "is configured to use". SLF4J plugs into appropriate logging framework through the org.slf4j.impl.StaticLoggerBinder class. Search the classpath (best in your IDE) to see what library this class came with. If there is no such class, then SLF4J logs nothing.

Log4j2 Servlet 3.0 not logging

I have a JAX-RS 2.0 application running on a Tomcat 7 server, and I'm using log4j2 along with SLF4J to record the server logs to a file.
I can't seem to get any logs to show up properly in my log file when running the server in production, although when I run my integration tests, logs are output correctly.
In production, the logs are merely redirected to the console instead.
My log4j2.xml file is located in the WEB-INF/classes folder, and I've included all the necessary dependencies as well.
My configuration file looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="trace">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<RollingFile name="file" fileName="log/trace.log" append="true" filePattern="log/trace.%i.log">
<PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %X %logger{36} - %msg%n"/>
<Policies>
<OnStartupTriggeringPolicy/>
<SizeBasedTriggeringPolicy size="10 MB" />
</Policies>
</RollingFile>
</Appenders>
<Loggers>
<Logger name="my.package" level="TRACE" additivity="false">
<AppenderRef ref="file"/>
</Logger>
<Root level="WARN">
<AppenderRef ref="file"/>
</Root>
</Loggers>
</Configuration>
The web.xml needs no configuration (I'm following the documentation found on the log4j2 website).
EDIT
I've tried setting the Root level to TRACE but everything still gets redirected to console. The file log/trace.log itself is created, it's just never written to. I also tried setting immediateFlush=true but that didn't have any impact either.
I noticed you have status logging (log4j internal logging) set to TRACE. This will dump log4j internal initialization messages to the console. It this what you mean?
Otherwise, the config you provide shows there is no logger that has an appender-ref pointing to the ConsoleAppender.
So, if you are also seeing your application logs being output to the console (in addition to log4j's status log messages), I suspect there is another log4j2.xml (or log4j2-test.xml) config file in the classpath somewhere.
Fortunately log4j's status logs should also show the location of the log4j config file, so you can confirm which config file is actually being loaded.
You can switch off status logging by setting <Configuration status="WARN"> after confirming all works correctly.
I figured it out!
Turns out I was using the gretty plug-in with gradle, which contains it's own logging package (the logback library).
It used it's own internal logback.xml which was redirecting to console. I fixed this by overwriting the internal logback.xml with my own (using logback's configuration) and now everything works as expected!

Log4J2 and Tomee Plus 7.0.47 not working

According to here, Log4j2 should work with Tomcat7.0.47. I'm using TomEE Plus 7.0.47.
I have a webapplication deployed with a log4j2.xml in my web-inf/classes folder. This is the config:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<File name="File" fileName="${sys:catalina.home}/logs/testapp.log">
<PatternLayout>
<pattern>%d %p %C{1.} [%t] %m%n</pattern>
</PatternLayout>
</File>
</Appenders>
<Loggers>
<Logger name="org.alex" level="TRACE" additivity="false">
<AppenderRef ref="File"/>
</Logger>
<Root level="INFO">
<AppenderRef ref="Console"/>
</Root>
</Loggers>
</Configuration>
I have a logger declared in a class with name org.alex.util.JSON:
private static final Logger LOG = LoggerFactory.getLogger(JSON.class);
I'm using slf4j-api 1.7.5, and have the following libs added to the tomcat lib:
slf4j-api-1.7.5.jar
log4j-api-2.0-rc1.jar
log4j-core-2.0-rc1.jar
log4j-slf4j-impl-2.0-rc1.jar
If I change the Configuration status to TRACE, I can see my configuration file being picked up and configuration happens as expected. Also I can see the MBeans being added.
However, there's not one logging statement ending up in my logfile. I debugged into the log4j2 Logger, and see that the isEnabled(...) method returns false because the logger (com.alex.util.JSON) has the level "ERROR" set, while the configuration set the package org.alex to TRACE.
Further investigation shows it uses a DefaultConfiguration configured for level=ERROR, and only root is configured. I'm thinking of a classloader issue, but I can't seem to figure out what the cause is and how to solve it.
Does anyone know what I'm doing wrong?
This should work on trunk
Btw saw log4j2 has hacks for tomcat and since tomee wraps classloaders not sure they work as expected...
This is very strange. Please raise a ticket for this in the Log4j2 issue tracker so the Log4j team can take a look.
The problem may go away if you put the jar files you mentioned inside WEB-INF/lib instead of in Tomcat's lib folder.
To be comple log4j2 relies on servletcontainerinitializer which are called after ejb and app scanning so ejbs can be loaded too early. Doing the same with a tomcat context listener would make it working better

log4j2 monthly log rollover

I'm using Log4J 2.0 to create logs for a project that I'm doing. The logs are small and I have a requirement to maintain them for 3 months. I'd like to have the current month's log with 3 archives (each containing a month's worth of logs).
The problem that I need help with is configuring log4j to rotate the logs at the beginning of the month (or the end of the month).
Pretty much every thing that I've found researching this problem is for log4j 1.x and talks about a datePattern parameter that doesn't appear to exist in 2.0.
Here's my log4j2.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<configuration status="warn" name="NKMS" packages="">
<appenders>
<FastRollingFile name="LogFile" fileName="logs/Tier2HttpServer.log" filePattern="logs/app-%d{yyyy-MM-dd}.log.gz">
<ThresholdFilter level="INFO" onMatch="ACCEPT" onMismatch="DENY"/>
<PatternLayout pattern="%d %p %c{1.} [%t] %m%n"/>
<Policies>
<TimeBasedTriggeringPolicy/>
<SizeBasedTriggeringPolicy size="250 MB"/>
</Policies>
<DefaultRolloverStrategy max="4"/>
</FastRollingFile>
<Console name="STDOUT" target="SYSTEM_OUT">
<PatternLayout pattern="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/>
</Console>
</appenders>
<loggers>
<logger name="mil.navy.nrl.itd.xml_filter" level="trace"/>
<root level="trace">
<appender-ref ref="STDOUT"/>
<appender-ref ref="LogFile"/>
</root>
</loggers>
</configuration>
I'm writing INFO and above to the log file and debug to the console (for now). The files are written to just fine, but they appear to rollover daily (which appears to be the default).
I've tried changing the FastRollingFile:filePattern to "'.'yyyy-MM" but that causes weird things to happen (only a single entry is written to file and an archive is immediately created).
I downloaded the source for log4j-2.0-beta8 and the PatternProcessor parses a RolloverFrequency that contains the enum RolloverFrequency.MONTHLY, but there again, I can't figure out how to implement / use it.
As always, any assistance or advice that you can provide would be GREATLY APPRECIATED!
-Ace
You may have found a bug. I would expect the filePattern of "logs/app-%d{yyyy-MM}.log.gz" to give you what you're looking for.
To clarify my understanding of the problem: The initial log event immediately triggers a rollover (creating an archive file). Instead, it should collect log events into the log file and not roll over until the end/beginning of the month. Is that description correct? Is there any other issue in addition to this initial unnecessary rollover?
Could I ask you to raise a JIRA ticket for this? https://issues.apache.org/jira/browse/LOG4J2

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