Fix server crash when File-Based Debug Logger is enabled

[Copilot]

Enabling the File-Based Debug Logger causes an immediate server crash via ClassCastException in Grizzly's FilterChainContext.toString(), which propagates through the RxJava pipeline as OnErrorNotImplementedException.

Root Cause

LoggerConfigManager sets the root JUL level to FINEST when the debug logger is enabled. This causes Grizzly's DefaultFilterChain.executeFilter() to enter its logging branch (isLoggable(FINEST) == true) and log the FilterChainContext via SLF4JBridgeHandler → MessageFormat → FilterChainContext.toString().

In Grizzly 3.0.1, FilterChainContext.toString() has a bytecode-level bug — decompiling the JAR reveals it emits a checkcast [C (char array cast) on the context message field:

67: invokevirtual #144  // Method getMessage:()Ljava/lang/Object;
70: checkcast     #145  // class "[C"   ← ClassCastException here
73: invokestatic  #146  // Method java/lang/String.valueOf:([C)Ljava/lang/String;

During LDAP write operations, message is a LdapResponseMessage, not a char[] — the cast fails.

Changes

• LoggerConfigManager.changeJulLogLevel(): Append org.glassfish.grizzly.level=FINE to the JUL config string. This caps Grizzly's effective JUL level at FINE, making isLoggable(FINEST) return false for all Grizzly loggers and bypassing the broken toString() path. Grizzly FINE/WARNING/SEVERE messages continue to flow normally.

• LdapMessages.LdapResponseMessage: Add toString() override for meaningful diagnostic output when the object appears in log messages.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• 1.0.17.172.in-addr.arpa
  • Triggering command: `/usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.forgerock.opendj.gendoc=true -Dorg.opends.server.ServerRoot=/tmp -Dorg.opends.quicksetup.Root=/path/to/opendj -Dcom.forgerock.opendj.ldap.tools.scriptName=control-panel -Dorg.forgerock.opendj.gendoc.trailing=include::./_exit-codes-0-gt0.adoc[]

include::./_control-panel-examples.adoc[]

-classpath /home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/opendj/lib/bootstrap.jar:/home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/dependency/freemarker-2.3.34.jar org.opends.guitools.controlpanel.ControlPanelLauncher --help /work/OpenDJ/Ope352:353:355 r --no�� --noprofile jar ndor/bin/git orting-api/3.0/m/usr/lib/jvm/temurin-17-jdk-amd64/lib/jspawnhelper` (dns block)

• Triggering command: `/usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.forgerock.opendj.gendoc=true -Dorg.opends.server.ServerRoot=/tmp -Dorg.opends.quicksetup.Root=/path/to/opendj -Dcom.forgerock.opendj.ldap.tools.scriptName=setup -Dorg.forgerock.opendj.gendoc.trailing=include::./_exit-codes-0-gt0.adoc[]

include::./_setup-examples.adoc[]

-classpath /home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/opendj/lib/bootstrap.jar:/home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/dependency/freemarker-2.3.34.jar org.opends.quicksetup.installer.SetupLauncher --help cal/bin/jar head mpil��` (dns block)

• Triggering command: `/usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.forgerock.opendj.gendoc=true -Dorg.opends.server.ServerRoot=/tmp -Dorg.opends.quicksetup.Root=/path/to/opendj -Dcom.forgerock.opendj.ldap.tools.scriptName=uninstall -Dorg.forgerock.opendj.gendoc.trailing=include::./_exit-codes-0-gt0.adoc[]

include::./_uninstall-examples.adoc[]

-classpath /home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/opendj/lib/bootstrap.jar:/home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/dependency/freemarker-2.3.34.jar org.opends.guitools.uninstaller.UninstallLauncher --help /usr/bin/jar er e-ma�� --noprofile refirebooter-20260330092139437_359.jar er .0.jar` (dns block)

• 6.0.a.9.d.a.e.f.f.f.2.5.e.1.e.7.0.0.0.0.0.0.0.0.0.0.0.0.0.8.e.f.ip6.arpa
  • Triggering command: `/usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.forgerock.opendj.gendoc=true -Dorg.opends.server.ServerRoot=/tmp -Dorg.opends.quicksetup.Root=/path/to/opendj -Dcom.forgerock.opendj.ldap.tools.scriptName=control-panel -Dorg.forgerock.opendj.gendoc.trailing=include::./_exit-codes-0-gt0.adoc[]

include::./_control-panel-examples.adoc[]

-classpath /home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/opendj/lib/bootstrap.jar:/home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/dependency/freemarker-2.3.34.jar org.opends.guitools.controlpanel.ControlPanelLauncher --help /work/OpenDJ/Ope352:353:355 r --no�� --noprofile jar ndor/bin/git orting-api/3.0/m/usr/lib/jvm/temurin-17-jdk-amd64/lib/jspawnhelper` (dns block)

• Triggering command: `/usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.forgerock.opendj.gendoc=true -Dorg.opends.server.ServerRoot=/tmp -Dorg.opends.quicksetup.Root=/path/to/opendj -Dcom.forgerock.opendj.ldap.tools.scriptName=setup -Dorg.forgerock.opendj.gendoc.trailing=include::./_exit-codes-0-gt0.adoc[]

include::./_setup-examples.adoc[]

-classpath /home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/opendj/lib/bootstrap.jar:/home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/dependency/freemarker-2.3.34.jar org.opends.quicksetup.installer.SetupLauncher --help cal/bin/jar head mpil��` (dns block)

• Triggering command: `/usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.forgerock.opendj.gendoc=true -Dorg.opends.server.ServerRoot=/tmp -Dorg.opends.quicksetup.Root=/path/to/opendj -Dcom.forgerock.opendj.ldap.tools.scriptName=uninstall -Dorg.forgerock.opendj.gendoc.trailing=include::./_exit-codes-0-gt0.adoc[]

include::./_uninstall-examples.adoc[]

-classpath /home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/opendj/lib/bootstrap.jar:/home/REDACTED/work/OpenDJ/OpenDJ/opendj-doc-generated-ref/target/dependency/freemarker-2.3.34.jar org.opends.guitools.uninstaller.UninstallLauncher --help /usr/bin/jar er e-ma�� --noprofile refirebooter-20260330092139437_359.jar er .0.jar` (dns block)

• central.sonatype.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.14/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.14/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.14 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.14/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/OpenDJ/OpenDJ org.codehaus.plexus.classworlds.launcher.Launcher dependency:resolve -pl opendj-grizzly -Dclassifier=sources -q (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.14/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.14/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.14 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.14/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/OpenDJ/OpenDJ org.codehaus.plexus.classworlds.launcher.Launcher compile -pl opendj-core,opendj-server-legacy -am -q (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.14/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.14/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.14 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.14/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/OpenDJ/OpenDJ org.codehaus.plexus.classworlds.launcher.Launcher install -pl opendj-maven-plugin -q ork/4.0.2/grizzly-framework-4.0.2-sources.jar (dns block)
• https://api.github.com/repos/OpenIdentityPlatform/OpenDJ/releases/latest
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.14/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.14/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.14 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.14/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/OpenDJ/OpenDJ org.codehaus.plexus.classworlds.launcher.Launcher install -DskipTests --no-transfer-progress -q /home/REDACTED/.m2java.base/java.lang.reflect=ALL-UNNAMED 60330092139437_341.jar p/bin/bash (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[maximthomas]

Tested locally, works fine with File-Based Debug Logger enabled