jsadebugd(1)

📦 version 8.492.09, in alpine 3.24, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💖 jsadebugd — the troubleshooting-tools girlie 💖

okay so bestie, welcome to jsadebugd from the Troubleshooting Tools corner of your manual (section 1, iykyk). she attaches to a Java process or a core file and then just... serves debug to everyone who asks. main character energy fr. 💅

heads up: this command is experimental and unsupported. she's that girl but she's on thin ice. 😭

✨ SYNOPSIS ✨

jsadebugd pid [ server-id ]

jsadebugd executable core [ server-id ]

so there's two whole ways to run her, and both are valid, no cap:

  • pid — the process ID of the process the debug server attaches to. this process must be a Java process, okay? not just any random lil guy. to get a list of Java processes running on a machine, use the jps(1) command. and listen — at most one instance of the debug server can be attached to a single process. one. that's it. she does not share. 🙈
  • executable — the Java executable from which the core dump was produced.
  • core — the core file the debug server should attach to.
  • server-id — an optional unique ID that you need when multiple debug servers are started on the same machine. remote clients have to use this ID to identify which particular debug server they want to attach to. within a single machine, this ID must be unique. no duplicates, periodt. 🌸

🌈 DESCRIPTION 🌈

the jsadebugd command attaches to a Java process or core file and acts as a debug server. remote clients like jstack, jmap, and jinfo can attach to the server through Java Remote Method Invocation (RMI). it's giving group chat but for debugging. 🫶

before you start the jsadebugd command, start the RMI registry with the rmiregistry command, like this — where $JAVA_HOME is the JDK installation directory:

rmiregistry -J-Xbootclasspath/p:$JAVA_HOME/lib/sajdi.jar

if the RMI registry was not started, then the jsadebugd command starts an RMI registry internally in a standard (1099) port. she's self-sufficient like that. 👑

the debug server can be stopped by sending a SIGINT to it. to send a SIGINT press Ctrl+C. bye bestie 👋

Note: this utility is unsupported and may or may not be available in future releases of the JDK. on Windows Systems where dbgeng.dll is not present, Debugging Tools For Windows must be installed to have these tools working. the PATH environment variable should contain the location of jvm.dll used by the target process, or the location from which the crash dump file was produced. for example, set PATH=%JDK_HOME%\jre\bin\client;%PATH%. yes this is a lot of setup. yes it's worth it. probably. 💀

🦋 SEE ALSO 🦋

the lil siblings, the friend group, the ensemble cast:

and that's the whole page, bestie!! this icon was living her best life in JDK 8, dated 21 November 2013 — a true vintage queen. 💜✨

📦 where this page comes from