I am trying to change log levels programmatically for a given keyword. For example If I have the log level set to OFF but want to see logs that contain "database" keyword, how can I do that? Is there a way to to that via java?
#fatCop's answer is mostly correct. You can start with log4j2.xml configured as
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn" name="AppName" packages="">
<RegexFilter regex="*database*" onMatch="DENY" onMismatch="DENY"/>
<Appenders>
<RollingFile name="RollingFile" fileName="logs/app.log"
filePattern="logs/app-%d{MM-dd-yyyy}.log.gz">
<PatternLayout>
<pattern>%d %p %c{1.} [%t] %m%n</pattern>
</PatternLayout>
<TimeBasedTriggeringPolicy />
</RollingFile>
</Appenders>
<Loggers>
<Root level="error">
<AppenderRef ref="RollingFile"/>
</Root>
</Loggers>
</Configuration>
Because this is using a global filter it will cause nothing to be logged. When you are ready to enable logging do
final LoggerContext loggerContext = LoggerContext.getContext(false);
final Configuration config = loggerContext.getConfiguration();
Filter filter = RegexFilter.createFilter("database", null, false, Result.ACCEPT, RESULT.DENY);
config.setFilter(filter);
When you want it disabled then replace the filter with a new one that is set back to DENY on a match.
Note that the logging level on the root logger is irrelevant since the filter is only accepting or denying events.
As per Log4j Filter Manual, you can use RegexFilter. Snippet referring to manual, the configuration for you can be like:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn" name="AppName" packages="">
<Appenders>
<RollingFile name="RollingFile" fileName="logs/app.log"
filePattern="logs/app-%d{MM-dd-yyyy}.log.gz">
<RegexFilter regex="*database*" onMatch="ACCEPT" onMismatch="DENY"/>
<PatternLayout>
<pattern>%d %p %c{1.} [%t] %m%n</pattern>
</PatternLayout>
<TimeBasedTriggeringPolicy />
</RollingFile>
</Appenders>
<Loggers>
<Root level="error">
<AppenderRef ref="RollingFile"/>
</Root>
</Loggers>
</Configuration>
Related
I'm using Log4j 2 to log the events of my application. However I'm stuck at the following problem.
Currently all logging messages are being written to two different appenders. One has RollingFile type, while the other has Console type.
What I want is for the RollingFile appender to log messages with an INFO level or higher (ERROR, FATAL), and for the Console appender to log messages with an ERROR level or higher (FATAL).
Inside my log4j2.xml file I seem to be only able to declare the logging level for an entire logger (including all of its appenders). Here is my log4j2.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration monitorInterval="30">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout>
<Pattern>%d %level %msg%n</Pattern>
</PatternLayout>
</Console>
<RollingFile name="Log" fileName="log/Log.log" filePattern="log/Log-%d{yyyy-MM-dd}-%i.log" append="false">
<PatternLayout>
<Pattern>%d %level %msg%n</Pattern>
</PatternLayout>
<Policies>
<SizeBasedTriggeringPolicy size="1 MB" />
</Policies>
<DefaultRolloverStrategy max="10"/>
</RollingFile>
</Appenders>
<Loggers>
<Root level="info">
<AppenderRef ref="Console" />
<AppenderRef ref="Log" />
</Root>
</Loggers>
</Configuration>
Is there an easy way of doing so? I searched log4j documentation but couldn't find what I was looking for (Maybe I missed it?). If it's possible I would really prefer for the solution to be applicable on any appenders' types; not specific for RollingFile and Console.
EDIT:
I saw many questions where it was asked to write ONLY the messages from a certain level to a file, while writing the messages from a different level to a different file. In my case I need the messages with a certain level of HIGHER to be written to different files. For example in the case I provided messages with level ERROR or FATAL will be written to both the RollingFile and Console, while messages with level INFO will be written to RollingFile only.
To limit logging level on specific appender in log4j2 you should use ThresholdFilter element of an appender.
In your case log4j2.xml file will look like:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration monitorInterval="30">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<ThresholdFilter level="ERROR" onMatch="ACCEPT" onMismatch="DENY"/>
<PatternLayout>
<Pattern>%d %level %msg%n</Pattern>
</PatternLayout>
</Console>
<RollingFile name="Log" fileName="log/Log.log" filePattern="log/Log-%d{yyyy-MM-dd}-%i.log" append="false">
<ThresholdFilter level="INFO" onMatch="ACCEPT" onMismatch="DENY"/>
<PatternLayout>
<Pattern>%d %level %msg%n</Pattern>
</PatternLayout>
<Policies>
<SizeBasedTriggeringPolicy size="1 MB" />
</Policies>
<DefaultRolloverStrategy max="10"/>
</RollingFile>
</Appenders>
<Loggers>
<Root level="info">
<AppenderRef ref="Console" />
<AppenderRef ref="Log" />
</Root>
</Loggers>
</Configuration>
Here is a simple test:
public class Log4jTest {
private static final Logger logger = LogManager.getLogger(Log4jTest.class);
public static void main(String[] args) {
logger.debug("Debug");
logger.info("Info");
logger.warn("Warning");
logger.error("Error");
logger.fatal("Fatal");
}
}
Console output:
2020-02-25 12:33:50,587 ERROR Error
2020-02-25 12:33:50,589 FATAL Fatal
Log.log contents:
2020-02-25 12:33:50,585 INFO Info
2020-02-25 12:33:50,587 WARN Warning
2020-02-25 12:33:50,587 ERROR Error
2020-02-25 12:33:50,589 FATAL Fatal
In first version of log4j it was Threshold property of appender. On how to solve the same in log4j see the answer on question.
With aid of filters Log4j2 allows to configure the output to a specific appender much more flexible then log4j.
This should do the trick.
<Loggers>
<Root level="debug" additivity="false">
<AppenderRef ref="Console"/>
</Root>
<Logger name="com.project.package" level="info" additivity="false">
<AppenderRef ref="Log" />
</Logger>
</Loggers>
Alternatively, you could do it like this - Different level of logs in different log files
BTW, this is explained very nicely in the Log4j2 documentation. See - https://logging.apache.org/log4j/2.x/manual/configuration.html
I'm wondering if the following is possible:
Based on the standard log4j2.xml file, I would like to insert the "Completed" string to the previous file, when switching to a new one.
Something like: "logs/app-09-18-2017_Completed.log"
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn" name="MyApp" packages="">
<Appenders>
<RollingFile name="RollingFile" fileName="logs/app.log"
filePattern="logs/app-%d{MM-dd-yyyy}.log"
<PatternLayout>
<Pattern>%m%n</Pattern>
</PatternLayout>
<TimeBasedTriggeringPolicy />
</RollingFile>
<Console name="STDOUT" target="SYSTEM_OUT">
<PatternLayout pattern="%m%n"/>
</Console>
</Appenders>
<Loggers>
<Root level="error">
<AppenderRef ref="SYSTEM_OUT"/>
<AppenderRef ref="RollingFile"/>
</Root>
</Loggers>
</Configuration>
Chaing the filePattern to
<RollingFile name="RollingFile" fileName="logs/app.log"
filePattern="logs/app_completed-%d{MM-dd-yyyy}.log">
shall help you. Since it treats the pattern as a string where the the DateFormat %d or the integer count %i is replaced.
private static final Logger log = LogManager.getLogger(ABC.class);
private static final Logger resultLog = LogManager.getLogger("ResultLog");
How can we define a appender that would only logs specific to "ResultLog" logger?
My current Log4j2.xml file looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn" name="ABC" packages="">
<Appenders>
<RollingFile name="RollingFile" fileName="logs/ABC.log"
filePattern="logs/$${date:yyyy-MM}/ABC-%d{MM-dd-yyyy}-%i.log.gz">
<PatternLayout>
<Pattern>%d [%t] %p %c{1.} %m%n</Pattern>
</PatternLayout>
<Policies>
<TimeBasedTriggeringPolicy/>
<SizeBasedTriggeringPolicy size="250 MB"/>
</Policies>
</RollingFile>
<File name="resultFile" fileName="logs/result.log">
<PatternLayout pattern="%m%n"/>
</File>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d [%t] %p %c{1.} %m%n"/>
</Console>
</Appenders>
<Loggers>
<Root level="debug">
<AppenderRef ref="RollingFile"/>
<AppenderRef ref="Console"/>
<AppenderRef ref="resultFile"/>
</Root>
</Loggers>
</Configuration>
thanks
Add
<Logger name="ResultLog">
<AppenderRef ...>
</Logger>
to the Loggers tag.
You can refer to this manual: https://logging.apache.org/log4j/2.x/manual/configuration.html#XML
I was using log4j2 and it was logging statements for me with no issues. I might have made some changes (moved from info to debug and back) but its quite possibly I might have messed up the config in some other fashion. I am copying my config file below (I have not moved any log4j2 and slf4j jar files from my project). Any thoughts?
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="debug" name="TestApp" packages="">
<Appenders>
<RollingRandomAccessFile name="RollingRandomAccessFile" fileName="logs/test.log" immediateFlush="false" append="false"
filePattern="logs/$${date:yyyy-MM}/app-%d{MM-dd-yyyy}-%i.log.gz">
<PatternLayout>
<Pattern>%d %p %c{1.} [%t] %m %ex%n</Pattern>
</PatternLayout>
<Policies>
<TimeBasedTriggeringPolicy />
<SizeBasedTriggeringPolicy size="500 MB"/>
</Policies>
</RollingRandomAccessFile>
</Appenders>
<Loggers>
<AsyncLogger name="FATAL_LOGGER" level="fatal" includeLocation="true" additivity="false">
<AppenderRef ref="RollingRandomAccessFile"/>
</AsyncLogger>
<Root level="debug" includeLocation="false">
<AppenderRef ref="RollingRandomAccessFile"/>
</Root>
</Loggers>
</Configuration>
I tested the config in a test project and it works without any issues. Ensure that you do not have any locks on the file and have correct read/write privileges on the file/directory.
I am trying log4j2 to create log file to the system I am developing right, I have followed the instruction on their site and there is no error occurred when I run it, but the log is not saved on where I set it (ex. "D:\logs\app.log").
Here is My log4j.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration status="OFF">
<appenders>
<RollingFile name="MyRollingFile" fileName="D:/logs/app.log"
filePattern="logs/$${date:yyyy-MM}/app-%d{MM-dd-yyyy}-%i.log.gz">
<PatternLayout>
<pattern>%d %p %C{1.} [%t] %m%n</pattern>
</PatternLayout>
<Policies>
<TimeBasedTriggeringPolicy />
<SizeBasedTriggeringPolicy size="250 MB"/>
</Policies>
<DefaultRolloverStrategy max="20"/>
</RollingFile>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
</appenders>
<loggers>
<logger name="Log_RollingFile" level="TRACE" additivity="false">
<appender-ref ref="MyRollingFile"/>
</logger>
<root level="ERROR">
<appender-ref ref="Console"/>
</root>
</loggers>
</configuration>
I tried to :
delete app.log to see if my configuration (D:\logs\app.log) works. When I run the application it creates app.log so I think it means that it sees the configuration and the only thing is it is NOT SAVING the log.info that I did in java application
Change root level to "TRACE", and it prints the log.info.
[EDIT:]
I have also these libraries on my classpath
log4j-api-2.0-beta3.jar
log4j-core-2.0-beta3.jar
Am I missing something on RollingFile configuration or a library (maybe)?
Thanks in advance.
Your logger name is incorrect.
As explained in the configuration instructions you linked to, the logger should be named according to the package/classes you wish to capture logging for.
In their example the logger named com.foo.Bar would log everything from the Bar class in package com.foo with TRACE level.