EDIT

cdm-server.log

    <dependency>

        <groupId>org.eclipse.jetty</groupId>

        <artifactId>jetty-webapp-logging</artifactId>

        <version>9.4.20.v20190813</version><!-- versioning independent of jetty core -->

        <type>pom</type><!-- we only need the dependencies like jul-to-slf4j managed in this pom! -->

    </dependency>

import eu.etaxonomy.cdm.server.logging.LoggingConfigurator;

    private final LoggingConfigurator loggingConfigurator = new LoggingConfigurator();

        logger.info("Starting " + APPLICATION_NAME);

        loggingConfigurator.configureServer();

        // server.setContexts(contexts);

        contexts.addHandler(loggingConfigurator.configureWebApp(cdmWebappContext, instance));

import org.slf4j.MDC;

import eu.etaxonomy.cdm.server.logging.InstanceLogWrapper;

                MDC.put(InstanceLogWrapper.CDM_INSTANCE, instance.getName());

            } finally {

                MDC.clear();

/**

* Copyright (C) 2020 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.server.logging;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.eclipse.jetty.server.Request;

import org.eclipse.jetty.server.handler.HandlerWrapper;

import org.slf4j.MDC;

/**

 * @author a.kohlbecker

 * @since Jun 9, 2020

 */

public class InstanceLogWrapper extends HandlerWrapper {

    /**

     * Key under which the instance name stored in the

     * Mapped Diagnostic Context (MDC)

     */

    public static final String CDM_INSTANCE = "cdmInstance";

    private String instanceName;

    public InstanceLogWrapper(String instanceName) {

        this.instanceName = instanceName;

    }

    @Override

    public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException

    {

        // Collect Info for NDC/MDC

        MDC.put(CDM_INSTANCE, instanceName);

        try

        {

            super.handle(target, baseRequest, request, response);

        }

        finally

        {

            // Pop info out / clear the NDC/MDC

            MDC.clear();

        }

    }

}

/**

* Copyright (C) 2020 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.server.logging;

import org.eclipse.jetty.server.Handler;

import org.eclipse.jetty.webapp.WebAppContext;

import org.slf4j.bridge.SLF4JBridgeHandler;

import eu.etaxonomy.cdm.server.instance.CdmInstance;

/**

 * The technique used in this class is based on the example

 * for a jetty server which uses a deployment manager, explained

 * in https://www.eclipse.org/jetty/documentation/9.4.29.v20200521/example-logging-logback-centralized.html.

 * In our situation of an embedded jetty which manages the cdm-webapp instance directly the

 * configuration need to be a bit different.

 *

 * The config files of the official example can be downloaded from

 * https://repo1.maven.org/maven2/org/eclipse/jetty/jetty-webapp-logging/9.4.20.v20190813/jetty-webapp-logging-9.4.20.v20190813-config.jar

 * extract the jar to examine the contained config files.

 *

 * @author a.kohlbecker

 * @since Jun 10, 2020

 */

public class LoggingConfigurator {

    public void configureServer() {

        // Configure logging (1)

        // > jetty-webapp-logging-9.4.20.v20190813-config/etc/jetty-jul-to-slf4j.xml

        SLF4JBridgeHandler.removeHandlersForRootLogger();

        SLF4JBridgeHandler.install();

        // >

        // jetty-webapp-logging-9.4.20.v20190813-config/resources/jetty-logging.properties

        System.setProperty("org.eclipse.jetty.util.log.class", org.eclipse.jetty.util.log.Slf4jLog.class.getName());

    }

    public Handler configureWebApp(WebAppContext cdmWebappContext, CdmInstance instance) {

        // > jetty-webapp-logging-9.4.20.v20190813-config/etc/jetty-webapp-logging.xml

        // ---> adds the org.eclipse.jetty.webapp.logging.CentralizedWebAppLoggingBinding

        // (from jetty-webapp-logging-9.4.20.v20190813.jar) to the DeploymentManager,

        // in the  cdm-server we are not using the DeploymentManager so

        // this needs to be done per web app explicitely:

        cdmWebappContext.addSystemClass("org.apache.log4j.");

        cdmWebappContext.addSystemClass("org.slf4j.");

        cdmWebappContext.addSystemClass("org.apache.commons.logging.");

        // > jetty-webapp-logging-9.4.20.v20190813-config/etc/jetty-mdc-handler.xml

        InstanceLogWrapper mdcHandler = new InstanceLogWrapper(instance.getName());

        mdcHandler.setHandler(cdmWebappContext); // wrap context handler

        return mdcHandler;

    }

}

<!-- 

This is the default logfile for the cdm-sever. 

Logback provides a system property variable (see ch.qos.logback.classic.util.ContextInitializer#CONFIG_FILE_PROPERTY) 

by which custom configuration files can be specified for production and test environments:

-Dlogback.configurationFile=file:/app/logback.xml

 -->

<configuration>

  <!-- address performance concern with jul-to-slf4j -->

  <contextListener class="ch.qos.logback.classic.jul.LevelChangePropagator">

    <resetJUL>true</resetJUL>

  </contextListener>

  <statusListener class="ch.qos.logback.core.status.OnConsoleStatusListener" />

  <property name="LOG_FOLDER" value="${cdm.logDir}:-${user.home}/.cdmLibrary/log}" />

  <property name="ROLL_DAY" value="%d{yyyy-MM-dd}" />

  <property name="ROLL_MINUTE" value="%d{yyyy-MM-dd-mm}" />

  <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">

    <append>true</append>

    <file>${LOG_FOLDER}/cdm-server.log</file>

    <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">

      <!-- daily rollover -->

      <fileNamePattern>${LOG_FOLDER}/cdm-server.${ROLL_DAY}.log.gz</fileNamePattern>

      <!-- keep 30 days' worth of history capped at 3GB total size -->

      <maxHistory>30</maxHistory>

      <totalSizeCap>3GB</totalSizeCap>

    </rollingPolicy>

    <encoder>

      <pattern>%d{HH:mm:ss.SSS} [%X{cdmInstance}] [%thread] %-5level %logger{36} - %msg%n</pattern>

    </encoder>

  </appender>

  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">

    <layout>

      <pattern>%d{HH:mm:ss.SSS} [%X{cdmInstance}] [%thread] %-5level %logger{36} - %msg%n</pattern>

    </layout>

  </appender>

  <logger name="eu.etaxonomy.cdm.server" level="INFO" />

  <logger name="eu.etaxonomy.cdm" level="INFO" />

  <!-- avoid vast amount of "getCitation not yet implemented" & "getProblems not yet implemented" messages -->

  <logger name="eu.etaxonomy.cdm.model.name.TaxonNameBase" level="ERROR" />

  <logger name="eu.etaxonomy.cdm.persistence.dao.initializer" level="ERROR" />

  <logger name="eu.etaxonomy.cdm.cache.CdmTransientEntityCacher" level="WARN" />

  <logger name="eu.etaxonomy.cdm.remote.controller.interceptor" level="WARN" />

  <!-- prevent CdmExceptionResolver from logging errors -->

  <logger name="eu.etaxonomy.cdm.persistence.dao.initializer" level="ERROR" />

  <!-- json-lib -->

  <logger name="net.sf.json.JSONObject" level="ERROR" />

  <!-- Hibernate -->

  <logger name="org.hibernate" level="WARN" />

  <logger name="org.hibernate.search" level="ERROR" />

  <logger name="org.hibernate.engine.StatefulPersistenceContext.ProxyWarnLog" level="ERROR" />

  <!--      > supress HHH90000003 -->

  <logger name="org.hibernate.orm.deprecation" level="ERROR" />

  <!--  connection pool -->

  <logger name="com.mchange.v2.c3p0" level="WARN" />

  <!-- suppress nasty ehcache OutOfMemory warnings -->

  <logger name="net.sf.ehcache.config.CacheConfiguration" level="WARN" />

  <logger name="org.eclipse.jetty" level="INFO" />

  <root level="WARN">

    <appender-ref ref="FILE" />

    <appender-ref ref="STDOUT" />

  </root>

</configuration>