Java monitoring for the command-line, profiler included

What steps will reproduce the problem?
1. Environment is Linux machine running IBM WebSphere8 64-bit.
2. Execute jvmtop against java pid.

What is the expected output? What do you see instead?

==> I get the following error ::

com.ibm.tools.attach.AttachNotSupportedException: target not found
        at com.ibm.tools.attach.javaSE.VirtualMachineImpl.attachTarget(VirtualMachineImpl.java:81)
        at com.ibm.tools.attach.javaSE.AttachProviderImpl.attachVirtualMachine(AttachProviderImpl.java:37)
        at ibm.tools.attach.J9AttachProvider.attachVirtualMachine(J9AttachProvider.java:60)
        at com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:221)
        at com.jvmtop.openjdk.tools.LocalVirtualMachine.getLocalVirtualMachine(LocalVirtualMachine.java:277)
        at com.jvmtop.VMDetailView.<init>(VMDetailView.java:23)
        at com.jvmtop.JvmTop.main(JvmTop.java:36)
com.ibm.tools.attach.AttachNotSupportedException: target not found
        at com.ibm.tools.attach.javaSE.VirtualMachineImpl.attachTarget(VirtualMachineImpl.java:81)
        at com.ibm.tools.attach.javaSE.AttachProviderImpl.attachVirtualMachine(AttachProviderImpl.java:37)
        at ibm.tools.attach.J9AttachProvider.attachVirtualMachine(J9AttachProvider.java:60)
        at com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:221)
        at com.jvmtop.VMInfo.processNewVM(VMInfo.java:134)
        at com.jvmtop.VMDetailView.<init>(VMDetailView.java:24)
        at com.jvmtop.JvmTop.main(JvmTop.java:36)
Error while attaching vm 13315
com.sun.tools.attach.AttachNotSupportedException: target not found
        at ibm.tools.attach.J9AttachProvider.attachVirtualMachine(J9AttachProvider.java:65)
        at com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:221)
        at com.jvmtop.VMInfo.processNewVM(VMInfo.java:134)
        at com.jvmtop.VMDetailView.<init>(VMDetailView.java:24)
        at com.jvmtop.JvmTop.main(JvmTop.java:36)
Exception in thread "main" java.lang.NullPointerException
        at com.jvmtop.VMInfo.processNewVM(VMInfo.java:147)
        at com.jvmtop.VMDetailView.<init>(VMDetailView.java:24)
        at com.jvmtop.JvmTop.main(JvmTop.java:36)


What version of the product are you using? On what operating system?

==> jvmtop 0.3 on Linux / CentOS 64-bit

Please provide any additional information below.

==> IBM JDK used to run WebSphere & execute jvmtop is the same :

java version "1.6.0"
Java(TM) SE Runtime Environment (build pxa6460_26sr1fp1-20120309_01(SR1 FP1))
IBM J9 VM (build 2.6, JRE 1.6.0 Linux amd64-64 20120308_104898 (JIT enabled, 
AOT enabled)
J9VM - R26_Java626_SR1_FP1_20120308_1511_B104898
JIT  - r11_20111028_21230ifx5
GC   - R26_Java626_SR1_FP1_20120308_1511_B104898
J9CL - 20120308_104898)
JCL  - 20120214_01

Original issue reported on code.google.com by [email protected] on 4 Apr 2013 at 4:45

What steps will reproduce the problem?
1. ./jvmtop.sh --once.
2.
3.

What is the expected output? What do you see instead?
Attached is the video screen record link.

What version of jvmtop are you using? On what operating system?
jvmtop 1.7.1

Please post the output of the following commands:
java -version
echo $JAVA_HOME  (for unix/linux systems)
echo %JAVA_HOME% (for windows)


Please provide any additional information below.

hi,

Like i had discussed about my intention to develop a nagios plugin by using 
jvmtop.sh, i completed the script. On testing. I get to see a shocking result 
about the thread creations in my linux centos box.  I set nagios to check and 
run script every 2 min. but when i looked at the performance in HTOP. i see the 
thread is continuously growing by .jvmtop.sh. I started on Friday. and today on 
monday it almost created a min 2000 thread!!. consuming 300MB resident memory, 
and all having priority 15.  

With this much thread creation by jvmtop, i dont think nagios plugin will work 
on top of it. below is the line which executes the jvmtop.sh and grep the jvm 
process.  eg: script.sh -j org.jboss.Main 

tmp_output=$(/usr/local/nagios/libexec/jvmtop.sh --once | grep $PROCESS)

Let me know whats your openion on this.

http://www29.zippyshare.com/v/5648707/file.html

Original issue reported on code.google.com by [email protected] on 12 Aug 2013 at 6:19

When I run jvmstat.sh I get following error message

 JvmTop 0.4.1 alpha (expect bugs)  amd64,  1 cpus, Linux 3.4.28-2.
 http://code.google.com/p/jvmtop

  PID MAIN-CLASS      HPCUR HPMAX NHCUR NHMAX    CPU     GC    VM USERNAME   #T DL
 1136 m.jvmtop.JvmTop   14m  958m    8m  130m  3.86%  0.00% 1.7.0     root   12
10449 artup.Bootstrap [ERROR: Could not attach to VM]


If I specify the pid I get following error message

Error while attaching vm 10449
com.sun.tools.attach.AttachNotSupportedException: Unable to open socket file: 
target process not responding or HotSpot VM not loaded
        at sun.tools.attach.LinuxVirtualMachine.<init>(LinuxVirtualMachine.java:102)
        at sun.tools.attach.LinuxAttachProvider.attachVirtualMachine(LinuxAttachProvider.java:63)
        at com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:213)
        at com.jvmtop.VMInfo.processNewVM(VMInfo.java:138)
        at com.jvmtop.VMDetailView.<init>(VMDetailView.java:24)
        at com.jvmtop.JvmTop.main(JvmTop.java:35)
Exception in thread "main" java.lang.NullPointerException
        at com.jvmtop.VMDetailView.printView(VMDetailView.java:32)
        at com.jvmtop.JvmTop.run(JvmTop.java:70)
        at com.jvmtop.JvmTop.main(JvmTop.java:35)


I'm using:
Linux 3.4.28-2.20-desktop #1 SMP PREEMPT Tue Jan 29 16:51:37 UTC 2013 (143156b) 
x86_64 x86_64 x86_64 GNU/Linux
java version "1.7.0"
Java(TM) SE Runtime Environment (build 1.7.0-b147)
Java HotSpot(TM) 64-Bit Server VM (build 21.0-b17, mixed mode)

Original issue reported on code.google.com by [email protected] on 29 Apr 2013 at 7:27

What steps will reproduce the problem?
1.  ./jvmtop.sh
2.
3.

What is the expected output? What do you see instead?
attached jvmtopout.jpg

What version of jvmtop are you using? On what operating system?

jvmtop-0.7.0

Please post the output of the following commands:
java -version
java version "1.6.0_25"
Java(TM) SE Runtime Environment (build 1.6.0_25-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.0-b11, mixed mode)

echo $JAVA_HOME  (for unix/linux systems)
echo %JAVA_HOME% (for windows)


Please provide any additional information below.

Kindly fix the scrolling mode. it would be nice to have it like linux TOP does. 
 and is it possible to display the output only once ? by which i am planning to 
develop a nagios script plugin which will get output from this and generate 
graphs. 

Awaiting your reply. 
Great work. thanks.

Original issue reported on code.google.com by [email protected] on 30 Jul 2013 at 5:38

Attachments:

• jvmtopout.JPG

Before submitting a bug report, please check the FAQ:
http://code.google.com/p/jvmtop/wiki/FAQ


What steps will reproduce the problem?
1.
2.
3.

What is the expected output? What do you see instead?


What version of jvmtop are you using? On what operating system?


Please post the output of the following commands:
java -version
echo $JAVA_HOME  (for unix/linux systems)
echo %JAVA_HOME% (for windows)


Please provide any additional information below.

Original issue reported on code.google.com by [email protected] on 11 Feb 2014 at 1:30

What steps will reproduce the problem?
1. Start jvmtop
2. Start Glassfish

What is the expected output? What do you see instead?

  PID MAIN-CLASS      HPCUR HPMAX NHCUR NHMAX    CPU     GC    VM USERNAME   #T DL
17169 m.jvmtop.JvmTop   26m 1715m    9m  130m  0.21%  0.00% O7U21    phill   12
java.io.IOException: Unable to open socket file: target process not responding 
or HotSpot VM not loaded
    at com.jvmtop.openjdk.tools.LocalVirtualMachine.loadManagementAgent(LocalVirtualMachine.java:341)
    at com.jvmtop.openjdk.tools.LocalVirtualMachine.startManagementAgent(LocalVirtualMachine.java:137)
    at com.jvmtop.openjdk.tools.ProxyClient.tryConnect(ProxyClient.java:367)
    at com.jvmtop.openjdk.tools.ProxyClient.connect(ProxyClient.java:349)
    at com.jvmtop.VMInfo.attachToVM(VMInfo.java:187)
    at com.jvmtop.VMInfo.processNewVM(VMInfo.java:146)
    at com.jvmtop.VMOverviewView.scanForNewVMs(VMOverviewView.java:132)
    at com.jvmtop.VMOverviewView.printView(VMOverviewView.java:25)
    at com.jvmtop.JvmTop.run(JvmTop.java:70)
    at com.jvmtop.JvmTop.main(JvmTop.java:41)
Caused by: com.sun.tools.attach.AttachNotSupportedException: Unable to open 
socket file: target process not responding or HotSpot VM not loaded
    at sun.tools.attach.BsdVirtualMachine.<init>(BsdVirtualMachine.java:90)
    at sun.tools.attach.BsdAttachProvider.attachVirtualMachine(BsdAttachProvider.java:63)
    at com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:213)
    at com.jvmtop.openjdk.tools.LocalVirtualMachine.loadManagementAgent(LocalVirtualMachine.java:337)
    ... 9 more
java.lang.reflect.UndeclaredThrowableException
    at com.sun.proxy.$Proxy5.getHeapMemoryUsage(Unknown Source)
    at com.jvmtop.VMInfo.update(VMInfo.java:235)
    at com.jvmtop.VMOverviewView.updateVMs(VMOverviewView.java:110)
    at com.jvmtop.VMOverviewView.printView(VMOverviewView.java:27)
    at com.jvmtop.JvmTop.run(JvmTop.java:70)
    at com.jvmtop.JvmTop.main(JvmTop.java:41)
Caused by: java.rmi.ConnectException: Connection refused to host: 
192.168.200.97; nested exception is:
    java.net.ConnectException: Connection refused
    at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:619)
    at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:216)
    at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:202)
    at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:128)
    at com.sun.jmx.remote.internal.PRef.invoke(Unknown Source)
    at javax.management.remote.rmi.RMIConnectionImpl_Stub.getAttributes(Unknown Source)
    at javax.management.remote.rmi.RMIConnector$RemoteMBeanServerConnection.getAttributes(RMIConnector.java:926)
    at com.jvmtop.openjdk.tools.ProxyClient$SnapshotInvocationHandler.getCachedAttributes(ProxyClient.java:1053)
    at com.jvmtop.openjdk.tools.ProxyClient$SnapshotInvocationHandler.getAttribute(ProxyClient.java:1012)
    at com.jvmtop.openjdk.tools.ProxyClient$SnapshotInvocationHandler.invoke(ProxyClient.java:994)
    at com.sun.proxy.$Proxy0.getAttribute(Unknown Source)
    at com.sun.jmx.mbeanserver.MXBeanProxy$GetHandler.invoke(MXBeanProxy.java:122)
    at com.sun.jmx.mbeanserver.MXBeanProxy.invoke(MXBeanProxy.java:167)
    at javax.management.MBeanServerInvocationHandler.invoke(MBeanServerInvocationHandler.java:265)
    ... 6 more
Caused by: java.net.ConnectException: Connection refused
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:391)
    at java.net.Socket.connect(Socket.java:579)
    at java.net.Socket.connect(Socket.java:528)
    at java.net.Socket.<init>(Socket.java:425)
    at java.net.Socket.<init>(Socket.java:208)
    at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(RMIDirectSocketFactory.java:40)
    at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(RMIMasterSocketFactory.java:146)
    at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:613)
    ... 19 more
Exception in thread "main" java.lang.reflect.UndeclaredThrowableException
    at com.sun.proxy.$Proxy6.findDeadlockedThreads(Unknown Source)
    at com.jvmtop.VMInfo.hasDeadlockThreads(VMInfo.java:330)
    at com.jvmtop.VMOverviewView.printVM(VMOverviewView.java:85)
    at com.jvmtop.VMOverviewView.printView(VMOverviewView.java:37)
    at com.jvmtop.JvmTop.run(JvmTop.java:70)
    at com.jvmtop.JvmTop.main(JvmTop.java:41)
Caused by: java.rmi.ConnectException: Connection refused to host: 
192.168.200.97; nested exception is:
    java.net.ConnectException: Connection refused
    at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:619)
    at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:216)
    at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:202)
    at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:128)
    at com.sun.jmx.remote.internal.PRef.invoke(Unknown Source)
    at javax.management.remote.rmi.RMIConnectionImpl_Stub.invoke(Unknown Source)
    at javax.management.remote.rmi.RMIConnector$RemoteMBeanServerConnection.invoke(RMIConnector.java:1017)
    at sun.reflect.GeneratedMethodAccessor23.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at com.jvmtop.openjdk.tools.ProxyClient$SnapshotInvocationHandler.invoke(ProxyClient.java:1002)
    at com.sun.proxy.$Proxy0.invoke(Unknown Source)
    at com.sun.jmx.mbeanserver.MXBeanProxy$InvokeHandler.invoke(MXBeanProxy.java:150)
    at com.sun.jmx.mbeanserver.MXBeanProxy.invoke(MXBeanProxy.java:167)
    at javax.management.MBeanServerInvocationHandler.invoke(MBeanServerInvocationHandler.java:265)
    ... 6 more
Caused by: java.net.ConnectException: Connection refused
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:391)
    at java.net.Socket.connect(Socket.java:579)
    at java.net.Socket.connect(Socket.java:528)
    at java.net.Socket.<init>(Socket.java:425)
    at java.net.Socket.<init>(Socket.java:208)
    at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(RMIDirectSocketFactory.java:40)
    at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(RMIMasterSocketFactory.java:146)
    at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:613)
    ... 20 more

What version of the product are you using? On what operating system?

0.5.0 Mac OS X

Original issue reported on code.google.com by [email protected] on 26 May 2013 at 3:45

What steps will reproduce the problem?
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1. start a JVM with user X
2. try to run jvmtop from another user, or root, it will not attach.
3. with JConsole I can attach to all JVMs when JConsole starts as root.

What is the expected output? What do you see instead?
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
More of a nice to have really.  I have close to 10 JVMs running on a system, 
all owned by different users, and it would be nice if I could monitor all of 
them from a single instance of jvmtop.

What version of the product are you using? On what operating system?
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

jvmtop 0.4.1

Mint 14, native install and inside VirtualBox, same results.

all JVMs use:
java version "1.7.0_21"
Java(TM) SE Runtime Environment (build 1.7.0_21-b11)
Java HotSpot(TM) 64-Bit Server VM (build 23.21-b01, mixed mode)


Please provide any additional information below.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Keep up the great work, I love this tool.



Sample output.
^^^^^^^^^^^^^^
# NOTE: 19563, 19509 and 19624 are all owned by a different user, running 
ZooKeeper.

inter01 jvmtop # id
uid=0(root) gid=0(root) groups=0(root)
inter01 jvmtop # ./jvmtop.sh
Error while attaching vm 19563
com.sun.tools.attach.AttachNotSupportedException: Unable to open socket file: 
target process not responding or HotSpot VM not loaded
    at sun.tools.attach.LinuxVirtualMachine.<init>(LinuxVirtualMachine.java:106)
    at sun.tools.attach.LinuxAttachProvider.attachVirtualMachine(LinuxAttachProvider.java:63)
    at com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:213)
    at com.jvmtop.VMInfo.processNewVM(VMInfo.java:138)
    at com.jvmtop.VMOverviewView.scanForNewVMs(VMOverviewView.java:132)
    at com.jvmtop.VMOverviewView.printView(VMOverviewView.java:25)
    at com.jvmtop.JvmTop.run(JvmTop.java:70)
    at com.jvmtop.JvmTop.main(JvmTop.java:41)
Error while attaching vm 19509
com.sun.tools.attach.AttachNotSupportedException: Unable to open socket file: 
target process not responding or HotSpot VM not loaded
    at sun.tools.attach.LinuxVirtualMachine.<init>(LinuxVirtualMachine.java:106)
    at sun.tools.attach.LinuxAttachProvider.attachVirtualMachine(LinuxAttachProvider.java:63)
    at com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:213)
    at com.jvmtop.VMInfo.processNewVM(VMInfo.java:138)
    at com.jvmtop.VMOverviewView.scanForNewVMs(VMOverviewView.java:132)
    at com.jvmtop.VMOverviewView.printView(VMOverviewView.java:25)
    at com.jvmtop.JvmTop.run(JvmTop.java:70)
    at com.jvmtop.JvmTop.main(JvmTop.java:41)
Error while attaching vm 19624
java.io.IOException: well-known file is not secure
    at sun.tools.attach.LinuxVirtualMachine.checkPermissions(Native Method)
    at sun.tools.attach.LinuxVirtualMachine.<init>(LinuxVirtualMachine.java:117)
    at sun.tools.attach.LinuxAttachProvider.attachVirtualMachine(LinuxAttachProvider.java:63)
    at com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:213)
    at com.jvmtop.VMInfo.processNewVM(VMInfo.java:138)
    at com.jvmtop.VMOverviewView.scanForNewVMs(VMOverviewView.java:132)
    at com.jvmtop.VMOverviewView.printView(VMOverviewView.java:25)
    at com.jvmtop.JvmTop.run(JvmTop.java:70)
    at com.jvmtop.JvmTop.main(JvmTop.java:41)

 JvmTop 0.4.1 alpha (expect bugs)  amd64, 12 cpus, Linux 3.5.0-28-
 http://code.google.com/p/jvmtop

  PID MAIN-CLASS      HPCUR HPMAX NHCUR NHMAX    CPU     GC    VM USERNAME   #T DL
19959 onsole.JConsole    8m 7134m   25m  130m  0.66%  0.24% O7U21     root   32 

20335 m.jvmtop.JvmTop   20m 7134m    8m  130m  0.41%  0.00% O7U21     root   14 

19563 .QuorumPeerMain [ERROR: Could not attach to VM] 
19509 .QuorumPeerMain [ERROR: Could not attach to VM] 
19624 .QuorumPeerMain [ERROR: Could not attach to VM]

inter01 jvmtop # ps -ef|grep java
zkadm1   19509     1  0 10:49 pts/2    00:00:02 
/inter/zkadm1/jdk1.7.0_21/bin/java [...]
zkadm2   19563     1  0 10:49 pts/2    00:00:02 
/inter/zkadm2/jdk1.7.0_21/bin/java [...]
zkadm3   19624     1  0 10:49 pts/2    00:00:06 
/inter/zkadm3/jdk1.7.0_21/bin/java [...]
root     20375 20288  0 11:05 pts/1    00:00:00 grep --colour=auto java

[...]: output cut, but it runs ZooKeeper instances.

Original issue reported on code.google.com by [email protected] on 23 May 2013 at 3:11

What steps will reproduce the problem?
1. Try and run with OS X
2. Does not work.  Says requires real JDK.

tools.jar is not packaged up as a separate jar in the OS X JDK.  You don't need 
to add it to the classpath like on Windows/Unix.  I wrote and tested the 
following fix:

if [ `uname` != 'Darwin' ] ; then
  if [ ! -f "$TOOLSJAR" ] ; then
    echo "$JAVA_HOME seems to be no JDK!" >&2
    exit 1
  fi
fi

Original issue reported on code.google.com by [email protected] on 10 Sep 2013 at 11:51

Hey,

just wanted to say thank you. This looks like a really awesome project. I tried 
looking around for source code, but couldn't find anything.

Is this something I can get access to?

Thanks,
Nik 

Original issue reported on code.google.com by [email protected] on 23 May 2013 at 4:41

Hey, this surely is a very handy tool. this essentially could be used for monitoring remote VMs. Is there any way for sampling like in JVisualVm? the current stats are "good to know" but, wouldn't help much in monitoring heap/CPU.

 JvmTop 0.6.0 alpha          amd64,  4 cpus, Linux 2.6.18-19
 http://code.google.com/p/jvmtop

ERROR: Could not attach to process.


java -version
java version "1.6.0_22"
Java(TM) SE Runtime Environment (build 1.6.0_22-b04)
Java HotSpot(TM) 64-Bit Server VM (build 17.1-b03, mixed mode)

Original issue reported on code.google.com by [email protected] on 12 Jul 2013 at 3:58

output_snap.txt

I'm a performance test engineer. I've been using jvmtop for a few months to monitor JVM statistics. As I've tallied the output with Jconsole, I've mostly observed similar stats in jvmtop as well. However during a recent test execution I've observed few entries of CPU% to go above 100% (120% being the highest). Now as I believe jvmtop provides cumulative CPU usage (not like top which provides more of core-wise details), need guidance on how to interpret this entries of beyond 100% usage.

I have tested Jdk 11 and with minimum changes, I am able to compile and run with JDK 11. All functionality is working fine. Please check if you can incorporate changes.

I have java jdk & jre installed on Ubuntu 20.04, and I added: JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64 to jvmtop.sh (line 10), as I saw in a tutorial. Im asuming this counts as having a valid JDK environment path, but even if it doesn't, I already tried everything I mention here: https://askubuntu.com/questions/1248311/running-jvmtop-profile-the-java-home-environment-variable

However I get this message: /usr/lib/jvm/java-11-openjdk-amd64/bin seems to be no JDK! oddly enough, the path in the error seems to include bin, even though I only specified it up to java-11-openjdk-amd64.

I did nothing more and nothing less than what I mentioned. Am I missing something?

@patric-r, I'm seeing this error with openjdk: [user@server jvmtop-0.8.0]$ ./jvmtop.sh /usr/lib/jvm/java-11-openjdk-11.0.3.7-0.el7_6.x86_64 seems to be no JDK!

It has something to do with the tools.jar [user@server jvmtop-0.8.0]$ grep -3 seems jvmtop.sh TOOLSJAR="$JAVA_HOME/lib/tools.jar"

if [ ! -f "$TOOLSJAR" ] ; then echo "$JAVA_HOME seems to be no JDK!" >&2 exit 1 fi

tools.jar which seems to be a prerequisite for running jvmtop was removed with java 9, see https://www.reddit.com/r/javahelp/comments/765mwr/installed_jdk_9_and_my_toolsjar_is_missing/

[user@server jvm]$ find /usr/lib/jvm/* -type f -name tools.jar [user@server jvm]$

So it can't be used at least with OpenJDK or Amazon Corretto in Version 11. Any ideas?