SA Debug attach to another jvm version possible?

Sharath Ballal sharath.ballal at oracle.com
Tue Aug 21 11:46:23 UTC 2018 

Hi Egor,

 

For JDK 9 and above try this.

 

1. Run the debuggee and get the <pid>

2. <jdk>\bin\jhsdb debugd <pid>  (you may need sudo on some platforms)

3. <jdk>\bin\java -Dsun.jvm.hotspot.runtime.VM.disableVersionCheck -m jdk.hotspot.agent/sun.jvm.hotspot.tools.HeapDumper localhost (sudo may be needed on some platforms)

 

I realized that more bugs are required to be opened.

1.  JDK 9 and above jhsdb jstack and other jhsdb tools do not take debug server as a parameter

2.  JStack and some other SA tools when invoked in the following manner gives a " remote configuration is not yet implemented" error

           <jdk>\bin\java -m jdk.hotspot.agent/sun.jvm.hotspot.tools.JStack localhost   (using same jdk as the debugee)

          Attaching to remote server localhost, please wait...

          Debugger attached successfully.

          Server compiler detected.

           JVM version is 11-ea+22

           remote configuration is not yet implemented

3.  Doc changes JDK 10 onwards as sa-jdi.jar has been removed.  This includes code samples.

 

I will open bugs for all of these.  

 

Thanks,

Sharath

 

 

From: Krystal Mok [mailto:rednaxelafx at gmail.com] 
Sent: Tuesday, August 21, 2018 4:18 PM
To: Egor Ushakov
Cc: Sharath Ballal; David Holmes; serviceability-dev at openjdk.java.net serviceability-dev at openjdk.java.net
Subject: Re: SA Debug attach to another jvm version possible?

 

You're probably looking for <javahome>/jdk.hotspot.agent.jmod ?

 

- Kris

 

On Tue, Aug 21, 2018 at 3:18 AM, Egor Ushakov <HYPERLINK "mailto:egor.ushakov at jetbrains.com"egor.ushakov at jetbrains.com> wrote:

Thank you all! It is much better now.

Related question: documentation for java 10 https://docs.oracle.com/javase/10/docs/specs/jpda/conninv.html#sa-pid-attaching-connector
still states that the debug server should be launched with sa-jdi.jar in classpath, though there's no such jar in the jdk any more.
java \
    -classpath ${JAVA_HOME}/lib/sa-jdi.jar \
    sun.jvm.hotspot.jdi.SADebugServer
How should it be launched on jdk 9, 10?

Thanks,
Egor



On 21-Aug-18 11:55, Sharath Ballal wrote:

Hi David,

I opened https://bugs.openjdk.java.net/browse/JDK-8209781 for it.

Thanks,
Sharath


-----Original Message-----
From: David Holmes
Sent: Tuesday, August 21, 2018 7:47 AM
To: Sharath Ballal; Egor Ushakov; HYPERLINK "mailto:serviceability-dev at openjdk.java.net"serviceability-dev at openjdk.java.net HYPERLINK "mailto:serviceability-dev at openjdk.java.net"serviceability-dev at openjdk.java.net
Subject: Re: SA Debug attach to another jvm version possible?

Hi Sharath,

On 21/08/2018 3:07 AM, Sharath Ballal wrote:

Hello Egor,

By default, SA checks for the exact match of the version between the
debugger and the debuggee.  If you

In that case we need to fix the referenced documentation that states otherwise.

Cheers,
David

want SA to ignore the version, you need to provide the "-Dsun.jvm.hotspot.runtime.VM.disableVersionCheck" option to the java launcher from the command line.  This is the case even if you are not using the debug server.  However since 'jstack' and similar tools don’t take the "-D" option of java, you can invoke it as follows:

java   -cp <jdk>/lib/sa-jdi.jar   -Dsun.jvm.hotspot.runtime.VM.disableVersionCheck   sun.jvm.hotspot.tools.JStack   localhost

If you invoke the SA tools with this option, you will get a warning that the version check has been disabled.

Example:
$ <jdk>/bin/java -cp <jdk>/lib/sa-jdi.jar
-Dsun.jvm.hotspot.runtime.VM.disableVersionCheck sun.jvm.hotspot.tools.JStack localhost Attaching to remote server localhost, please wait...
WARNING: You have disabled SA and VM version check. You may be using incompatible version of SA and you may see unexpected results.
Debugger attached successfully.
Server compiler detected.
JVM version is 25.121-b13
Deadlock Detection:

No deadlocks found.

Thread t@ 2804: (state = BLOCKED)


Thread t@ 2803: (state = BLOCKED)
   - java.lang.Object.wait(long) @bci=0 (Interpreted frame)
   - java.lang.ref.ReferenceQueue.remove(long) @bci=59, line=143 (Interpreted frame)
   - java.lang.ref.ReferenceQueue.remove() @bci=2, line=164 (Interpreted frame)
   - java.lang.ref.Finalizer$FinalizerThread.run() @bci=36, line=209
(Interpreted frame)


Thread t@ 2802: (state = BLOCKED)
   - java.lang.Object.wait(long) @bci=0 (Interpreted frame)
   - java.lang.Object.wait() @bci=2, line=502 (Interpreted frame)
   - java.lang.ref.Reference.tryHandlePending(boolean) @bci=54, line=191 (Interpreted frame)
   - java.lang.ref.Reference$ReferenceHandler.run() @bci=1, line=153
(Interpreted frame)


Thread t@ 2798: (state = BLOCKED)
   - java.lang.Thread.sleep(long) @bci=0 (Interpreted frame)
   - HelloWorld.main(java.lang.String[]) @bci=72, line=15 (Interpreted
frame)


Hope this helps.

Thanks,
Sharath


-----Original Message-----
From: Egor Ushakov [mailto:HYPERLINK "mailto:egor.ushakov at jetbrains.com"egor.ushakov at jetbrains.com]
Sent: Monday, August 20, 2018 3:42 PM
To: HYPERLINK "mailto:serviceability-dev at openjdk.java.net"serviceability-dev at openjdk.java.net
HYPERLINK "mailto:serviceability-dev at openjdk.java.net"serviceability-dev at openjdk.java.net
Subject: SA Debug attach to another jvm version possible?

Hi all,

documentation for SA Debug Server Attaching Connector here:
https://docs.oracle.com/javase/8/docs/technotes/guides/jpda/conninv.ht
ml#Connectors states that the SADebugServer has to run on the same vm
version as the debugee process, but "the debugger does not have to be the same bit size and version."
However any attempts to connect from another version fail with sun.jvm.hotspot.runtime.VMVersionMismatchException.

Please help, what do I do wrong (locally for simplicity):
- start the debugee process with jdk1.8.0_162  - get the PID
- start "jdk1.8.0_162\bin>jsadebugd.exe PID" - all starts well
- trying to attach jstack, jdb or whatever from another version:
jdk1.8.0_152\bin>jstack localhost
Attaching to remote server localhost, please wait...
Error attaching to remote server:
sun.jvm.hotspot.runtime.VMVersionMismatchException: Supported versions
are 25.152-b16. Target VM is 25.162-b12
sun.jvm.hotspot.debugger.DebuggerException:
sun.jvm.hotspot.runtime.VMVersionMismatchException: Supported versions
are 25.152-b16. Target VM is 25.162-b12

jdk1.8.0_152\bin>jdb -connect
"sun.jvm.hotspot.jdi.SADebugServerAttachingConnector:debugServerName=localhost"
java.io.IOException
           at
sun.jvm.hotspot.jdi.SADebugServerAttachingConnector.attach(SADebugServerAttachingConnector.java:106)
           at
HYPERLINK "http://com.sun.tools.example.debug.tt"com.sun.tools.example.debug.tty.VMConnection.attachTarget(VMConnection.java:519)
           at
HYPERLINK "http://com.sun.tools.example.debug.tt"com.sun.tools.example.debug.tty.VMConnection.open(VMConnection.java:328)
           at HYPERLINK "http://com.sun.tools.example.debug.tt"com.sun.tools.example.debug.tty.Env.init(Env.java:63)
           at HYPERLINK "http://com.sun.tools.example.debug.tt"com.sun.tools.example.debug.tty.TTY.main(TTY.java:1082)
Caused by: java.lang.reflect.InvocationTargetException
           at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
           at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
           at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
           at java.lang.reflect.Method.invoke(Method.java:498)
           at
sun.jvm.hotspot.jdi.SADebugServerAttachingConnector.createVirtualMachine(SADebugServerAttachingConnector.java:72)
           at
sun.jvm.hotspot.jdi.SADebugServerAttachingConnector.attach(SADebugServerAttachingConnector.java:91)
           ... 4 more
Caused by: sun.jvm.hotspot.debugger.DebuggerException:
sun.jvm.hotspot.runtime.VMVersionMismatchException: Supported versions are 25.152-b16. Target VM is 25.162-b12
           at sun.jvm.hotspot.HotSpotAgent.setupVM(HotSpotAgent.java:435)
           at sun.jvm.hotspot.HotSpotAgent.go(HotSpotAgent.java:305)
           at sun.jvm.hotspot.HotSpotAgent.attach(HotSpotAgent.java:183)
           at
sun.jvm.hotspot.jdi.VirtualMachineImpl.createVirtualMachineForServer(VirtualMachineImpl.java:241)
           ... 10 more
Caused by: sun.jvm.hotspot.runtime.VMVersionMismatchException: Supported versions are 25.152-b16. Target VM is 25.162-b12
           at sun.jvm.hotspot.runtime.VM.checkVMVersion(VM.java:227)
           at sun.jvm.hotspot.runtime.VM.<init>(VM.java:294)
           at sun.jvm.hotspot.runtime.VM.initialize(VM.java:370)
           at sun.jvm.hotspot.HotSpotAgent.setupVM(HotSpotAgent.java:431)
           ... 13 more

Thanks!

--
Egor Ushakov
Software Developer
JetBrains
http://www.jetbrains.com
The Drive to Develop


-- 
Egor Ushakov
Software Developer
JetBrains
http://www.jetbrains.com
The Drive to Develop

 
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