Garbage Free Logger

What is it ?

The garbage-free logger IS NOT a general purpose logger as log4j, logback or similar.

The goal is to create ad-hoc logger for low latency (latency critical) applications (to be precise for latency critical execution path) which will affect application explicit and implicit (though gc pauses) as less as it possible. It means that it will not be a general purpose logger. As well it means that this logger should not be a log4j or logback (or whatever you like) killer - that's ok to combine them using e.g. log4j for the initial application phase and this logger for latency critical execution path.

There are some known by design limitation.

gflogger DOES NOT have :

• garbage overhead on the fly except initialization and file rolling phases
• unlimited message length
• ability to track changes of :
  • thread name
  • time zone and locale
• different types of appenders as jms appender, email appender and so on

gflogger has :

• zero object delivery property on the normal fly
• appenders: file, daily rolling file, console (stream)
• compatible with log4j message pattern format ** but MDC, NDC
• compatible with log4j log levels: trace, debug, info, warn, error, fatal
• category heirarchy support
• configurators: xml, java api

Read further a garbage free logger post in blog.

How it use

QuickStart

gflogger.xml

<configuration 
    xmlns="http://bitbucket.org/vladimir.dolzhenko/gflogger"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://bitbucket.org/vladimir.dolzhenko/gflogger 
        https://raw.githubusercontent.com/vladimirdolzhenko/gflogger/master/core/src/main/resources/gflogger.xsd">

    <appender name="fileAppender"
        class="org.gflogger.appender.DailyRollingFileAppenderFactory"
        fileName="${logs.root}/${instanceName}/${instanceName}.log"
        datePattern="'.'yyyy-MM-dd-HH">
            <layout class="org.gflogger.PatternLayout"
                pattern="%d{MMM d HH:mm:ss,SSS zzz} %p - %m [%c{2}] [%t]%n" timeZoneId="GMT"/>
    </appender>
    
    <logger name="com.db" logLevel="INFO">
        <appender-ref ref="fileAppender"/> 
    </logger>
    
    <root logLevel="WARN">
        <appender-ref ref="fileAppender"/> 
    </root>

    <service count="1024" maxMessageSize="4096">
        <object-formatter 
            class="org.gflogger.perftest.SomeObject"
            formatter="org.gflogger.perftest.SomeObjectFormatter"/>
    </service>

</configuration>

load configuration

// uses system property gflogger.configuration
// or default gflogger.xml file
 org.gflogger.config.xml.XmlLogFactoryConfigurator.configure();

usage

private static final org.gflogger.GFLog log = 
    org.gflogger.GFLogFactory.getLog(MyClass.class);

// somewhere in method, the modern way:
log.info( "value of %s is %s" ).with( name ).with( value );

// the same with the orthodox approach
log.info().
      append( "value of " ).append( name ).
      append( " is " ).append( value ).
    commit();

How it works