Arguments line of remote JVM cropped at 1024 characters

[ro-kr]

For a remote JVM instance connected to via jstatd the JVM arguments line is cropped at a limit of 1024 characters. This is visible in the JVM arguments tab of the JVM window. It also affects a custom name of the JVM, if specified by JVM CLI option visualvm.display.name. VisualVM parses this option from the JVM arguments line. If the option appears (partly) beyond the 1024 characters limit then VisualVM displays a cropped name or completely ignores the custom name.

I guess this bug is caused by #291 and affects all versions since 2.1.0.

[thurka]

I don't think this is caused by #291. Can you please provide more information? Steps to reproduce would be great. Note that for remote connection, JMX must be also available, otherwise there is a default limit of 1024 characters imposed by jvmstat. You can change it by adding -XX:PerfMaxStringConstLength=new_limit to command line of the monitored application.

[thurka]

@ro-kr Any update?

[ro-kr]

@thurka Sorry for the late answer, I somehow overlooked your response.
Adding -XX:PerfMaxStringConstLength=... does the job.
Thanks for the hint.

[ro-kr]

I thought that the issue was caused by #291 due to a bug in method JVMImpl.getJvmArgsJvmstat:

JVMImpl.java

private String getJvmArgsJvmstat() {
    String args = jvmstatModel.getJvmArgs();
    if (args.length() == 1024) {
        AttachModel attach = getAttach();
        if (attach != null) {
            args = attach.getJvmArgs();
        }
        if (args == null) {
            args = jmxSupport.getJvmArgs();
        }
        ...

If the call to getAttach() returns null (since the JVM is not local) then jmxSupport.getJvmArgs() is not called because args is not null.
I think args should be reset to null right before the call to getAttach(), at the top of the if block.

[thurka]

You are right. I will fix it.

[ro-kr]

Great, thanks!

[thurka]

Fixed in master.