Chapter 20. Log
Chapter 20. Log Apache Karaf provides a dynamic and powerful logging system. It supports: the OSGi Log Service the Apache Log4j v1 and v2 framework the Apache Commons Logging framework the Logback framework the SLF4J framework the native Java Util Logging framework It means that the applications can use any logging framework, Apache Karaf will use the central log system to manage the loggers, appenders, etc. 20.1. Configuration files The initial log configuration is loaded from etc/org.ops4j.pax.logging.cfg . This file is a standard Log4j2 configuration file . You find the different Log4j2 elements: loggers appenders layouts You can add your own initial configuration directly in the file. The default configuration is as follows: The default configuration defines the ROOT logger, with INFO log level, using the out file appender. You can change the log level to any Log4j2 valid value. From most verbose to least verbose, you can specify TRACE, DEBUG, INFO, ERROR, or FATAL. osgi appender The osgi:* appender is a special appender to send the log message to the OSGi Log Service. stdout appender A stdout console appender is pre-configured, but not enabled by default. This appender allows you to display log messages directly to standard output. It's interesting if you plan to run Apache Karaf in server mode (without console). To enable it, you have to add the stdout appender to the rootLogger : out appender The out appender is the default one. It is a rolling file appender that maintains and rotates 10 1MB log files. The log files are located in data/log/fuse.log by default. sift appender The sift appender is not enabled by default. This appender allows you to have one log file per deployed bundle. By default, the log file name format uses the bundle symbolic name (in the data/log folder). You can edit this file at runtime. Apache Karaf reloads the file and the changes are in effect. You do not need to restart Apache Karaf. Another configuration file is used by Apache Karaf: etc/org.apache.karaf.log.cfg . This files configures the Log Service used by the log commands (see later). jdbc appender The jdbc appender has a lazy flag, that when true ( enabled ), if a datasource is unavailable, logging is not added to a database. However, when jndi, datasource or connection comes back, the logging restarts. Important If you want to avoid losing logging messages, we also recomend configuring an emergency appender. 20.2. Commands Instead of changing the etc/org.ops4j.pax.logging.cfg file, Apache Karaf provides a set of commands allowing to dynamically change the log configuration and see the log content: 20.2.1. log:clear The log:clear command clears the log entries. 20.2.2. log:display The log:display command displays the log entries. By default, it displays the log entries of the rootLogger : You can also display the log entries from a specific logger, using the logger argument: By default, all log entries will be displayed. It could be very long if your Apache Karaf container is running since a long time. You can limit the number of entries to display using the -n option: You can also limit the number of entries stored and retained using the size property in etc/org.apache.karaf.log.cfg file: By default, each log level is displayed with a different color: ERROR/FATAL are in red, DEBUG in purple, INFO in cyan, etc. You can disable the coloring using the --no-color option. The log entries format pattern doesn't use the conversion pattern define in etc/org.ops4j.pax.logging.cfg file. By default, it uses the pattern property defined in etc/org.apache.karaf.log.cfg . You can also change the pattern dynamically (for one execution) using the -p option: The pattern is a regular Log4j2 pattern where you can use keywords such as %d for the date, %c for the class, %m for the log message, etc. 20.2.3. log:exception-display The log:exception-display command displays the last occurred exception. As for log:display command, the log:exception-display command uses the rootLogger by default, but you can specify a logger with the logger argument. 20.2.4. log:get The log:get command show the current log level of a logger. By default, the log level shown is the one from the root logger: You can specify a particular logger using the logger argument: The logger argument accepts the ALL keyword to display the log level of all logger (as a list). For example, if you have defined your own logger in etc/org.ops4j.pax.logging.cfg file like this: you can see the list of loggers with the corresponding log level: The log:list command is an alias to log:get ALL . 20.2.5. log:log The log:log command allows you to manually add a message in the log. It's interesting when you create Apache Karaf scripts: By default, the log level is INFO, but you can specify a different log level using the -l option: 20.2.6. log:set The log:set command sets the log level of a logger. By default, it changes the log level of the rootLogger : You can specify a particular logger using the logger argument, after the level one: The level argument accepts any Log4j2 log level: TRACE, DEBUG, INFO, WARN, ERROR, FATAL. By it also accepts the DEFAULT special keyword. The purpose of the DEFAULT keyword is to delete the current level of the logger (and only the level, the other properties like appender are not deleted) in order to use the level of the logger parent (logger are hierarchical). For example, you have defined the following loggers (in etc/org.ops4j.pax.logging.cfg file): You can change the level of my.logger.custom logger: Now we have: You can use the DEFAULT keyword on my.logger.custom logger to remove the level: Now we have: It means that, at runtime, the my.logger.custom logger uses the level of its parent my.logger , so INFO . Now, if we use DEFAULT keyword with the my.logger logger: We have: So, both my.logger.custom and my.logger use the log level of the parent rootLogger . It's not possible to use DEFAULT keyword with the rootLogger and it doesn't have parent. 20.2.7. log:tail The log:tail is exactly the same as log:display but it continuously displays the log entries. You can use the same options and arguments as for the log:display command. By default, it displays the entries from the rootLogger : To exit from the log:tail command, just type CTRL-C. 20.3. JMX LogMBean All actions that you can perform with the log:* command can be performed using the LogMBean. The LogMBean object name is org.apache.karaf:type=log,name=* . 20.3.1. Attributes Level attribute is the level of the ROOT logger. 20.3.2. Operations getLevel(logger) to get the log level of a specific logger. As this operation supports the ALL keyword, it returns a Map with the level of each logger. setLevel(level, logger) to set the log level of a specific logger. This operation supports the DEFAULT keyword as for the log:set command. 20.4. Advanced configuration 20.4.1. SIFT logging Fuse-Karaf provides sample (commented out by default) configuration of Log4j2 sift appender and a logger using this appender in USDFUSE_HOME/etc/org.ops4j.pax.logging.cfg file: The configuration is described in http://logging.apache.org/log4j/2.x/manual/appenders.html#RoutingAppender pattern property of SIFT/Routing appender is what can be used to distinguish the target locations for logging. There are different lookups available and described here: http://logging.apache.org/log4j/2.x/manual/lookups.html the most important lookup is ctx one, which looks up the values (keys) in ThreadContext map (a.k.a. MDC). The default configuration provided by Fuse Karaf uses ctx:bundle.name as the pattern, which means: the bundle. prefixed keys are provided by pax-logging itself and there are 3 different values to choose from: bundle.name == org.osgi.framework.Bundle.getSymbolicName() bundle.id == org.osgi.framework.Bundle.getBundleId() bundle.version == org.osgi.framework.Bundle.getVersion().toString() However, if Camel context is created with MDC support using (blueprint XML DSL): there will me more keys available in MDC/ThreadContext, which then can be used as a pattern in SIFT appender configuration: camel.exchangeId - The exchange id camel.messageId - The message id camel.correlationId - The correlation id of the exchange if it's correlated. For example a sub message from the Splitter EIP camel.transactionKey - The id of the transaction for transacted exchanges. Note the id is not unique, but its the id of the transaction template that marks the transaction boundary for the given transaction. Hence we decided to name the key transactionKey and not transactionID to point out this fact. camel.routeId - The id of the route, in which the exchange is currently being routed camel.breadcrumbId - An unique id used for tracking messages across transports. camel.contextId - The camel context id used for tracking the message from different camel context. See https://people.apache.org/~dkulp/camel/mdc-logging.html So for example, in order to distinguish logging destination files by Camel's route ID, please use: One more thing - sole appender configuration is not enough - you have to attach it to some logger. Again, sample configuration contains: (note that SiftAppender value of log4j2.logger.example.appenderRef.SiftAppender.ref property should match the value of log4j2.appender.mdc.name in the appender configuration). Here, org.apache.camel is a logger name (or category name). This is exactly the same value that's used in Camel's log: endpoint. So if you have (in Camel route): The logging would work. Another working configuration would be: and: 20.4.2. Filters You can apply a filter to an appender. A filter evaluates each log event and determines whether to send it to the log. Log4j2 provides ready to use filters. Note See Filters on the Log4J site for a comprehensive view into these. 20.4.3. Nested appenders A nested appender is a special kind of appender that you use "inside" another appender. It allows you to create some kind of "routing" between a chain of appenders. The most used "nested compliant" appenders are: The AsyncAppender ( org.apache.log4j2.AsyncAppender ) logs events asynchronously. This appender collects the events and dispatch them to all the appenders that are attached to it. The RewriteAppender ( org.apache.log4j2.rewrite.RewriteAppender ) forwards log events to another appender after possibly rewriting the log event. This kind of appender accepts an appenders property in the appender definition: For example, you can create an AsyncAppender named async and asynchronously dispatch the log events to a JMS appender: 20.4.4. Error handlers Sometimes, appenders can fail. For example, a RollingFileAppender tries to write to the filesystem, but the filesystem is full, or a JMS appender tries to send a message, but the JMS broker is unavailable. Logging can be critical so it is important to know if the log appender fails. Each log appender can delegate error handling to an error handler, which provides a chance to react to an appender error. The FailoverAppender ( org.apache.log4j2.varia.FailoverAppender ) allows a secondary appender to take over if the primary appender fails. The error message is printed on System.err , and logged in the secondary appender. Note For more on the FailoverAppender , go to Log4j2's Apppender Page . You can define the error handler that you want to use for each appender using the errorhandler property on the appender definition itself: 20.4.5. OSGi specific MDC attributes The routing appender is a OSGi oriented appender allowing you to split the log events based on MDC (Mapped Diagnostic Context) attributes. MDC allows you to distinguish the different source of log events. The routing appender provides OSGi-oriented MDC attributes by default: bundle.id is the bundle ID bundle.name is the bundle symbolic name bundle.version is the bundle version You can use these MDC properties to create a log file per bundle: 20.4.6. Enhanced OSGi stack trace renderer By default, Apache Karaf provides a special stack trace renderer, adding some OSGi specific specific information. In the stack trace, in addition of the class throwing the exception, you can find a pattern [id:name:version] at the end of each stack trace line, where: id is the bundle ID name is the bundle name version is the bundle version It's very helpful to diagnosing the source of an issue. For example, in the following IllegalArgumentException stack trace, we can see the OSGi details about the source of the exception: 20.4.7. Custom appenders You can use your own appenders in Apache Karaf. The easiest way to do that is to package your appender as an OSGi bundle and attach it as a fragment of the org.ops4j.pax.logging.pax-logging-service bundle. For example, you create MyAppender : You compile and package as an OSGi bundle containing a MANIFEST looking like: Copy your bundle in the Apache Karaf system folder. The system folder uses a standard Maven directory layout: groupId/artifactId/version. In the etc/startup.properties configuration file, you define your bundle in the list before the pax-logging-service bundle. You have to restart Apache Karaf with a clean run (purging the data folder) in order to reload the system bundles. You can now use your appender directly in etc/org.ops4j.pax.logging.cfg configuration file.
# Copyright 2005-2018 Red Hat, Inc. # Red Hat licenses this file to you under the Apache License, version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at # http://www.apache.org/licenses/LICENSE-2.0 # Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. # # Internal Log4j2 configuration # log4j2.status = WARN log4j2.verbose = false log4j2.dest = out # Common pattern layouts for appenders defined as reusable properties See https://logging.apache.org/log4j/2.x/manual/layouts.html#PatternLayout references will be replaced by felix.fileinstall # log4j2.pattern = %d{DEFAULT} | %-5.5p | %-20.20t | %-32.32c{1.} | %X{bundle.id} - %X{bundle.name} - %X{bundle.version} | %m%n #log4j2.pattern = %d{DEFAULT} %-5.5p {%t} [%C.%M()] (%F:%L) : %m%n # Appenders configuration # JDBC Appender log4j2.appender.jdbc.type = JDBC log4j2.appender.jdbc.name = JdbcAppender log4j2.appender.jdbc.tableName = EVENTS log4j2.appender.jdbc.cs.type = DataSource log4j2.appender.jdbc.cs.lazy = true log4j2.appender.jdbc.cs.jndiName = osgi:service/jdbc/logdb log4j2.appender.jdbc.c1.type = Column log4j2.appender.jdbc.c1.name = DATE log4j2.appender.jdbc.c1.isEventTimestamp = true log4j2.appender.jdbc.c2.type = Column log4j2.appender.jdbc.c2.name = LEVEL log4j2.appender.jdbc.c2.pattern = %level log4j2.appender.jdbc.c2.isUnicode = false log4j2.appender.jdbc.c3.type = Column log4j2.appender.jdbc.c3.name = SOURCE log4j2.appender.jdbc.c3.pattern = %logger log4j2.appender.jdbc.c3.isUnicode = false log4j2.appender.jdbc.c4.type = Column log4j2.appender.jdbc.c4.name = THREAD_ID log4j2.appender.jdbc.c4.pattern = %thread log4j2.appender.jdbc.c4.isUnicode = false log4j2.appender.jdbc.c5.type = Column log4j2.appender.jdbc.c5.name = MESSAGE log4j2.appender.jdbc.c5.pattern = %message log4j2.appender.jdbc.c5.isUnicode = false Console appender not used by default (see log4j2.rootLogger.appenderRefs) log4j2.appender.console.type = Console log4j2.appender.console.name = Console log4j2.appender.console.layout.type = PatternLayout log4j2.appender.console.layout.pattern = USD{log4j2.pattern} Rolling file appender log4j2.appender.rolling.type = RollingRandomAccessFile log4j2.appender.rolling.name = RollingFile log4j2.appender.rolling.fileName = USD{karaf.data}/log/fuse.log log4j2.appender.rolling.filePattern = USD{karaf.data}/log/fuse-%i.log.gz uncomment to not force a disk flush #log4j2.appender.rolling.immediateFlush = false log4j2.appender.rolling.append = true log4j2.appender.rolling.layout.type = PatternLayout log4j2.appender.rolling.layout.pattern = USD{log4j2.pattern} log4j2.appender.rolling.policies.type = Policies log4j2.appender.rolling.policies.size.type = SizeBasedTriggeringPolicy log4j2.appender.rolling.policies.size.size = 16MB log4j2.appender.rolling.strategy.type = DefaultRolloverStrategy log4j2.appender.rolling.strategy.max = 20 Audit file appender log4j2.appender.audit.type = RollingRandomAccessFile log4j2.appender.audit.name = AuditRollingFile log4j2.appender.audit.fileName = USD{karaf.data}/security/audit.log log4j2.appender.audit.filePattern = USD{karaf.data}/security/audit.log.%i log4j2.appender.audit.append = true log4j2.appender.audit.layout.type = PatternLayout log4j2.appender.audit.layout.pattern = USD{log4j2.pattern} log4j2.appender.audit.policies.type = Policies log4j2.appender.audit.policies.size.type = SizeBasedTriggeringPolicy log4j2.appender.audit.policies.size.size = 8MB OSGi appender log4j2.appender.osgi.type = PaxOsgi log4j2.appender.osgi.name = PaxOsgi log4j2.appender.osgi.filter = * # Loggers configuration # Root logger log4j2.rootLogger.level = INFO log4j2.rootLogger.appenderRef.RollingFile.ref = RollingFile log4j2.rootLogger.appenderRef.PaxOsgi.ref = PaxOsgi log4j2.rootLogger.appenderRef.Console.ref = Console log4j2.rootLogger.appenderRef.Console.filter.threshold.type = ThresholdFilter log4j2.rootLogger.appenderRef.Console.filter.threshold.level = USD{karaf.log.console:-OFF} #log4j2.rootLogger.appenderRef.Sift.ref = Routing Spifly logger log4j2.logger.spifly.name = org.apache.aries.spifly log4j2.logger.spifly.level = WARN Security audit logger log4j2.logger.audit.name = org.apache.karaf.jaas.modules.audit log4j2.logger.audit.level = INFO log4j2.logger.audit.additivity = false log4j2.logger.audit.appenderRef.AuditRollingFile.ref = AuditRollingFile help with identification of maven-related problems with pax-url-aether #log4j2.logger.aether.name = shaded.org.eclipse.aether #log4j2.logger.aether.level = TRACE #log4j2.logger.http-headers.name = shaded.org.apache.http.headers #log4j2.logger.http-headers.level = DEBUG #log4j2.logger.maven.name = org.ops4j.pax.url.mvn #log4j2.logger.maven.level = TRACE log4j2.rootLogger=INFO, out, stdout, osgi:* log4j2.appender.jdbc.cs.lazy = true karaf@root()> log:display 2015-07-01 19:12:46,208 | INFO | FelixStartLevel | SecurityUtils | 16 - org.apache.sshd.core - 0.12.0 | BouncyCastle not registered, using the default JCE provider 2015-07-01 19:12:47,368 | INFO | FelixStartLevel | core | 68 - org.apache.aries.jmx.core - 1.1.1 | Starting JMX OSGi agent karaf@root()> log:display ssh 2015-07-01 19:12:46,208 | INFO | FelixStartLevel | SecurityUtils | 16 - org.apache.sshd.core - 0.12.0 | BouncyCastle not registered, using the default JCE provider karaf@root()> log:display -n 5 2015-07-01 06:53:24,143 | INFO | JMX OSGi Agent | core | 68 - org.apache.aries.jmx.core - 1.1.1 | Registering org.osgi.jmx.framework.BundleStateMBean to MBeanServer com.sun.jmx.mbeanserver.JmxMBeanServer@27cc75cb with name osgi.core:type=bundleState,version=1.7,framework=org.apache.felix.framework,uuid=5335370f-9dee-449f-9b1c-cabe74432ed1 2015-07-01 06:53:24,150 | INFO | JMX OSGi Agent | core | 68 - org.apache.aries.jmx.core - 1.1.1 | Registering org.osgi.jmx.framework.PackageStateMBean to MBeanServer com.sun.jmx.mbeanserver.JmxMBeanServer@27cc75cb with name osgi.core:type=packageState,version=1.5,framework=org.apache.felix.framework,uuid=5335370f-9dee-449f-9b1c-cabe74432ed1 2015-07-01 06:53:24,150 | INFO | JMX OSGi Agent | core | 68 - org.apache.aries.jmx.core - 1.1.1 | Registering org.osgi.jmx.framework.ServiceStateMBean to MBeanServer com.sun.jmx.mbeanserver.JmxMBeanServer@27cc75cb with name osgi.core:type=serviceState,version=1.7,framework=org.apache.felix.framework,uuid=5335370f-9dee-449f-9b1c-cabe74432ed1 2015-07-01 06:53:24,152 | INFO | JMX OSGi Agent | core | 68 - org.apache.aries.jmx.core - 1.1.1 | Registering org.osgi.jmx.framework.wiring.BundleWiringStateMBean to MBeanServer com.sun.jmx.mbeanserver.JmxMBeanServer@27cc75cb with name osgi.core:type=wiringState,version=1.1,framework=org.apache.felix.framework,uuid=5335370f-9dee-449f-9b1c-cabe74432ed1 2015-07-01 06:53:24,501 | INFO | FelixStartLevel | RegionsPersistenceImpl | 78 - org.apache.karaf.region.persist - 4.0.0 | Loading region digraph persistence # The number of log statements to be displayed using log:display. It also defines the number of lines searched for exceptions using log:display exception. You can override this value at runtime using -n in log:display. # size = 500 # The pattern used to format the log statement when using log:display. This pattern is according to the log4j2 layout. You can override this parameter at runtime using log:display with -p. # pattern = %d{ISO8601} | %-5.5p | %-16.16t | %-32.32c{1} | %X{bundle.id} - %X{bundle.name} - %X{bundle.version} | %m%n karaf@root()> log:display -p "\%d - \%c - \%m\%n" 2015-07-01 07:01:58,007 - org.apache.sshd.common.util.SecurityUtils - BouncyCastle not registered, using the default JCE provider 2015-07-01 07:01:58,725 - org.apache.aries.jmx.core - Starting JMX OSGi agent 2015-07-01 07:01:58,744 - org.apache.aries.jmx.core - Registering MBean with ObjectName [osgi.compendium:service=cm,version=1.3,framework=org.apache.felix.framework,uuid=6361fc65-8df4-4886-b0a6-479df2d61c83] for service with service.id [13] 2015-07-01 07:01:58,747 - org.apache.aries.jmx.core - Registering org.osgi.jmx.service.cm.ConfigurationAdminMBean to MBeanServer com.sun.jmx.mbeanserver.JmxMBeanServer@27cc75cb with name osgi.compendium:service=cm,version=1.3,framework=org.apache.felix.framework,uuid=6361fc65-8df4-4886-b0a6-479df2d61c83 karaf@root()> log:get Logger │ Level ────────────────────────────────────┼────── ROOT │ INFO org.apache.aries.spifly │ WARN org.apache.karaf.jaas.modules.audit │ INFO org.apache.sshd │ INFO karaf@root()> log:get ssh INFO log4j2.logger.my.name = MyLogger log4j2.logger.my.level = DEBUG karaf@root()> log:get ALL Logger │ Level ────────────────────────────────────┼────── MyLogger │ DEBUG ROOT │ INFO org.apache.aries.spifly │ WARN org.apache.karaf.jaas.modules.audit │ INFO org.apache.sshd │ INFO karaf@root()> log:log "Hello World" karaf@root()> log:display 12:55:21.706 INFO [pipe-log:log "Hello World"] Hello World karaf@root()> log:clear karaf@root()> log:log -l ERROR "Hello World" karaf@root()> log:display 12:55:41.460 ERROR [pipe-log:log "Hello World"] Hello World karaf@root()> log:set DEBUG karaf@root()> log:get Logger │ Level ────────────────────────────────────┼────── ROOT │ DEBUG karaf@root()> log:set INFO my.logger karaf@root()> log:get my.logger Logger | Level ----------------- my.logger | INFO rootLogger=INFO,out,osgi:* my.logger=INFO,appender1 my.logger.custom=DEBUG,appender2 karaf@root()> log:set INFO my.logger.custom rootLogger=INFO,out,osgi:* my.logger=INFO,appender1 my.logger.custom=INFO,appender2 karaf@root()> log:set DEFAULT my.logger.custom rootLogger=INFO,out,osgi:* my.logger=INFO,appender1 my.logger.custom=appender2 karaf@root()> log:set DEFAULT my.logger rootLogger=INFO,out,osgi:* my.logger=appender1 my.logger.custom=appender2 karaf@root()> log:tail 2015-07-01 07:40:28,152 | INFO | FelixStartLevel | SecurityUtils | 16 - org.apache.sshd.core - 0.9.0 | BouncyCastle not registered, using the default JCE provider 2015-07-01 07:40:28,909 | INFO | FelixStartLevel | core | 68 - org.apache.aries.jmx.core - 1.1.1 | Starting JMX OSGi agent 2015-07-01 07:40:28,928 | INFO | FelixStartLevel | core | 68 - org.apache.aries.jmx.core - 1.1.1 | Registering MBean with ObjectName [osgi.compendium:service=cm,version=1.3,framework=org.apache.felix.framework,uuid=b44a44b7-41cd-498f-936d-3b12d7aafa7b] for service with service.id [13] 2015-07-01 07:40:28,936 | INFO | JMX OSGi Agent | core | 68 - org.apache.aries.jmx.core - 1.1.1 | Registering org.osgi.jmx.service.cm.ConfigurationAdminMBean to MBeanServer com.sun.jmx.mbeanserver.JmxMBeanServer@27cc75cb with name osgi.compendium:service=cm,version=1.3,framework=org.apache.felix.framework,uuid=b44a44b7-41cd-498f-936d-3b12d7aafa7b Sift appender log4j2.appender.mdc.type = Routing log4j2.appender.mdc.name = SiftAppender log4j2.appender.mdc.routes.type = Routes see: http://logging.apache.org/log4j/2.x/manual/appenders.html#Routes log4j2.appender.mdc.routes.pattern = USD\\{ctx:bundle.name} log4j2.appender.mdc.routes.sift.type = Route log4j2.appender.mdc.routes.sift.appender.type = RollingRandomAccessFile log4j2.appender.mdc.routes.sift.appender.name = RollingFile log4j2.appender.mdc.routes.sift.appender.fileName = USD{karaf.data}/log/sift-USD\\{ctx:bundle.name}.log log4j2.appender.mdc.routes.sift.appender.filePattern = USD{karaf.data}/log/sift-USD\\{ctx:bundle.name}-%i.log.gz log4j2.appender.mdc.routes.sift.appender.append = true log4j2.appender.mdc.routes.sift.appender.layout.type = PatternLayout log4j2.appender.mdc.routes.sift.appender.layout.pattern = USD{log4j2.pattern} log4j2.appender.mdc.routes.sift.appender.policies.type = Policies log4j2.appender.mdc.routes.sift.appender.policies.size.type = SizeBasedTriggeringPolicy log4j2.appender.mdc.routes.sift.appender.policies.size.size = 16MB log4j2.appender.mdc.routes.sift.appender.strategy.type = DefaultRolloverStrategy log4j2.appender.mdc.routes.sift.appender.strategy.max = 20 sample logger using Sift appender #log4j2.logger.example.name = org.apache.camel #log4j2.logger.example.level = INFO #log4j2.logger.example.appenderRef.SiftAppender.ref = SiftAppender lookup bundle.name key in MDC <camelContext id="my-context" xmlns="http://camel.apache.org/schema/blueprint" useMDCLogging="true"> log4j2.appender.mdc.routes.pattern = USD\\{ctx:camel.routeId} log4j2.appender.mdc.routes.sift.appender.fileName = USD{karaf.data}/log/sift-USD\\{ctx:camel.routeId}.log log4j2.appender.mdc.routes.sift.appender.filePattern = USD{karaf.data}/log/sift-USD\\{ctx:camel.routeId}-%i.log.gz sample logger using Sift appender #log4j2.logger.example.name = org.apache.camel #log4j2.logger.example.level = INFO #log4j2.logger.example.appenderRef.SiftAppender.ref = SiftAppender <to uri="log:org.apache.camel" /> <to uri="log:my-special-logger" /> log4j2.logger.example.name = my-special-logger log4j2.logger.example.level = DEBUG log4j2.logger.example.appenderRef.SiftAppender.ref = SiftAppender log4j2.appender.[appender-name].appenders=[comma-separated-list-of-appender-names] log4j2.appender.async=org.apache.log4j2.AsyncAppender log4j2.appender.async.appenders=jms log4j2.appender.jms=org.apache.log4j2.net.JMSAppender log4j2.appender.[appender-name].errorhandler=[error-handler-class] log4j2.appender.[appender-name].errorhandler.root-ref=[true|false] log4j2.appender.[appender-name].errorhandler.logger-ref=[logger-ref] log4j2.appender.[appender-name].errorhandler.appender-ref=[appender-ref] log4j2.appender.routing.type = Routing log4j2.appender.routing.name = Routing log4j2.appender.routing.routes.type = Routes log4j2.appender.routing.routes.pattern = USDUSD\\{ctx:bundle.name\\} log4j2.appender.routing.routes.bundle.type = Route log4j2.appender.routing.routes.bundle.appender.type = RollingRandomAccessFile log4j2.appender.routing.routes.bundle.appender.name = Bundle-USD\\{ctx:bundle.name\} log4j2.appender.routing.routes.bundle.appender.fileName = USD{karaf.data}/log/bundle-USD\\{ctx:bundle.name\\}.log log4j2.appender.routing.routes.bundle.appender.filePattern = USD{karaf.data}/log/bundle-USD\\{ctx:bundle.name\\}.log.%d{yyyy-MM-dd} log4j2.appender.routing.routes.bundle.appender.append = true log4j2.appender.routing.routes.bundle.appender.layout.type = PatternLayout log4j2.appender.routing.routes.bundle.appender.policies.type = Policies log4j2.appender.routing.routes.bundle.appender.policies.time.type = TimeBasedTriggeringPolicy log4j2.appender.routing.routes.bundle.appender.strategy.type = DefaultRolloverStrategy log4j2.appender.routing.routes.bundle.appender.strategy.max = 31 log4j2.rootLogger.appenderRef.Routing.ref = Routing java.lang.IllegalArgumentException: Command not found: *:foo at org.apache.felix.gogo.runtime.shell.Closure.execute(Closure.java:225)[21:org.apache.karaf.shell.console:4.0.0] at org.apache.felix.gogo.runtime.shell.Closure.executeStatement(Closure.java:162)[21:org.apache.karaf.shell.console:4.0.0] at org.apache.felix.gogo.runtime.shell.Pipe.run(Pipe.java:101)[21:org.apache.karaf.shell.console:4.0.0] at org.apache.felix.gogo.runtime.shell.Closure.execute(Closure.java:79)[21:org.apache.karaf.shell.console:4.0.0] at org.apache.felix.gogo.runtime.shell.CommandSessionImpl.execute(CommandSessionImpl.java:71)[21:org.apache.karaf.shell.console:4.0.0] at org.apache.karaf.shell.console.jline.Console.run(Console.java:169)[21:org.apache.karaf.shell.console:4.0.0] at java.lang.Thread.run(Thread.java:637)[:1.7.0_21] public class MyAppender extends AppenderSkeleton { } Manifest: Bundle-SymbolicName: org.mydomain.myappender Fragment-Host: org.ops4j.pax.logging.pax-logging-service