Java, Semeru Runtimes and Runtimes for Business

Java, Semeru Runtimes and Runtimes for Business

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  • 1.  Using JFR Runtime Options

    Posted 10/24/25 03:04 PM

    Has anyone successfully used JFR (-XX) options?  

    IBM's doc has instructions on using jcmd through the JVM attach facility only.  Using the attach facility would be awkward for me because the jobs run under a different ID than mine.

    I can start recording with the -XX:StartFlightRecording option and get a trace under the default file name.  But if I try to do something like, -"XX:StartFlightRecording=settings=default.jfc" or "-XX:FlightRecorderOptions=filename=myrecording.jfr" I get no recording at all.

    This makes me wonder if Semeru supports the command line options at all.

    Thanks.



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    Robert Crawford
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  • 2.  RE: Using JFR Runtime Options

    Posted 10/27/25 08:57 AM

    Hi Robert, 

    Semeru does not yet support JFR command line options.  We've only begun our journey to add complete support for JFR.  Our currently released MVP only supports a few commands via JCMD at this time, but we are incrementally adding additional JFR features and events with each quarterly release.  Full command line support will be coming in 2026.

    Tony Renaud

    Semeru Software Dev Manager



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    Tony Renaud
    Senior Development Manager
    IBM
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  • 3.  RE: Using JFR Runtime Options

    Posted 10/27/25 09:49 AM

    Hi Tony,

    Thank you for your answer.

    Does development have an ETA for when JFR will be fully supported?



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    Robert Crawford
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    Original Message


  • 4.  RE: Using JFR Runtime Options

    Posted 10/28/25 09:40 AM

    Sorry, didn't read your reply fully before I asked the question.  Look forward to the support next year.



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    Robert Crawford
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    Original Message


  • 5.  RE: Using JFR Runtime Options

    Posted 10/28/25 10:46 AM

    @Tobi Ajila

    I couldn't find the reply button for your email so I'm posting this here.

    I successfully used jcmd to find and attach to a JVM running under my ID.  However, we submit the code I want to monitor from a scheduling system (Control-M) which gives the job a service ID.  jcmd was unable to find that JVM when I enabled the attach interface.  I assumed the problem was our ID's and group ID didn't match.

    I will reread the doc for jcmd to see how to specify an ID.  That would certainly be easier than submitting two jobs through Control-M so I'll give it a whirl.

    Please let me know if you have any additional information that might help. 

    Thanks.



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    Robert Crawford
    IT Contractor
    Abstract Evolution
    San Antonio TX
    (210) 913-3822
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