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log4j 1.2.x JSON Layout

Following settings can be used:

Attribute Name Description Default
lineBreak End of line string platform dependent default value, see System.getProperty("line.separator")
fields Comma-separated list of log event fields that should be included in the JSON Time, Severity, ThreadName, SourceClassName, SourceMethodName, SourceSimpleClassName, LoggerName, NDC, Server
version GELF Version 1.0 or 1.1 1.0
originHost Originating Hostname FQDN Hostname
extractStackTrace Send the Stack-Trace to the StackTrace field (true/false) false
filterStackTrace Perform Stack-Trace filtering (true/false) false
facility Name of the Facility logstash-gelf
mdcProfiling Perform Profiling (Call-Duration) based on MDC Data. See MDC Profiling for details false
additionalFields Send additional static fields. The fields are specified as key-value pairs are comma-separated. Example: GelfLogHandler.additionalFields=fieldName=Value,fieldName2=Value2 none
additionalFieldTypes Type specification for additional and MDC fields. Supported types: String, long, Long, double, Double and discover (default if not specified, discover field type on parseability). Eg. field=String,field2=double discover for all additional fields
mdcFields Send additional fields whose values are obtained from MDC. Name of the Fields are comma-separated. Example: mdcFields=Application,Version,SomeOtherFieldName none
dynamicMdcFields Dynamic MDC Fields allows you to extract MDC values based on one or more regular expressions. Multiple regexes are comma-separated. The name of the MDC entry is used as GELF field name. none
includeFullMdc Include all fields from the MDC. false
timestampPattern Date/time pattern for the Time field yyyy-MM-dd HH:mm:ss,SSSS

The JSON formatter creates then messages like:

{
    "LoggerName": "org.wildfly.extension.undertow",
    "short_message": "WFLYUT0008: Undertow HTTP listener default suspending",
    "level": "6",
    "Time": "2015-08-11 21:25:32,0734",
    "Severity": "INFO",
    "MessageParam1": "default",
    "Thread": "MSC service thread 1-6",
    "SourceMethodName": "stopListening",
    "MessageParam0": "HTTP",
    "full_message": "WFLYUT0008: Undertow HTTP listener default suspending",
    "SourceSimpleClassName": "HttpListenerService",
    "SourceClassName": "org.wildfly.extension.undertow.HttpListenerService",
    "facility": "java-test",
    "timestamp": "1439321132.734"
}

Default line break depends on the platform, JSON objects are separated by line breaks only.

log4j Configuration

Properties:

log4j.appender.file.layout=biz.paluch.logging.gelf.log4j.GelfLayout
log4j.appender.file.layout.Version=1.0
log4j.appender.file.layout.Facility=java-test
log4j.appender.file.layout.ExtractStackTrace=true
log4j.appender.file.layout.FilterStackTrace=true
log4j.appender.file.layout.MdcProfiling=true
log4j.appender.file.layout.TimestampPattern=yyyy-MM-dd HH:mm:ss,SSSS
log4j.appender.file.layout.AdditionalFields=fieldName1=fieldValue1,fieldName2=fieldValue2
log4j.appender.file.layout.AdditionalFieldTypes=fieldName1=String,fieldName2=Double,fieldName3=Long
log4j.appender.file.layout.MdcFields=mdcField1,mdcField2
log4j.appender.file.layout.DynamicMdcFields=mdc.*,(mdc|MDC)fields
log4j.appender.file.layout.IncludeFullMdc=true

XML:

<appender name="file" class="org.apache.log4j.FileAppender">
    <param name="file" value="logfile.log" />
    <layout class="biz.paluch.logging.gelf.log4j.GelfLayout">
        <param name="Facility" value="java-test" />
        <param name="ExtractStackTrace" value="true" />
        <param name="FilterStackTrace" value="true" />
        <param name="MdcProfiling" value="true" />
        <param name="TimestampPattern" value="yyyy-MM-dd HH:mm:ss,SSSS" />
        <param name="AdditionalFields" value="fieldName1=fieldValue1,fieldName2=fieldValue2" />
        <param name="AdditionalFieldTypes" value="fieldName1=String,fieldName2=Double,fieldName3=Long" />
        <param name="MdcFields" value="mdcField1,mdcField2" />
        <param name="DynamicMdcFields" value="mdc.*,(mdc|MDC)fields" />
        <param name="IncludeFullMdc" value="true" />
    </layout>
</appender>