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Java Dump using Putty but not Native OMVS interface

  • 1.  Java Dump using Putty but not Native OMVS interface

    Posted Tue January 05, 2021 05:34 AM
      |   view attached
    Hello 
    I have a strange problem.  Z/OS 2.1 and Jdk8 64bit installed
    If I type this command from OMVS interface I get the correct result:
    If I type the same command from putty interface i get an error 
    # java -version
    Unhandled exception
    Type=Segmentation error vmState=0xffffffff
    J9Generic_Signal_Number=00000018 Signal_Number=0000000b Error_Value=00000000 Signal_Code=00000035
    Handler1=0000004808E1F838 Handler2=00000048086F7D80

    with a java error file: javacore.20210105.062003.33554449.0002.txt that I attach
    these the most rilevant lines:

    0SECTION TITLE subcomponent dump routine
    NULL ===============================
    1TICHARSET IBM-1047
    1TISIGINFO Dump Event "gpf" (00002000) received
    1TIDATETIME Date: 2021/01/05 at 06:20:05:438
    1TINANOTIME System nanotime: 1609845605445711534
    1TIFILENAME Javacore filename: /u/ibmuser/javacore.20210105.062003.33554449.0002.txt
    1TIREQFLAGS Request Flags: 0x1 (exclusive)
    1TIPREPSTATE Prep State: 0x0
    1TIPREPINFO Exclusive VM access not taken: data may not be consistent across javacore sections
    NULL ------------------------------------------------------------------------
    0SECTION GPINFO subcomponent dump routine
    NULL ================================
    2XHOSLEVEL OS Level : z/OS 02.01.00
    2XHCPUS Processors -
    3XHCPUARCH Architecture : s390x
    3XHNUMCPUS How Many : 4
    3XHNUMASUP NUMA is either not supported or has been disabled by user
    NULL
    1XHERROR2 Register dump section only produced for SIGSEGV, SIGILL or SIGFPE.
    NULL
    NULL ------------------------------------------------------------------------
    0SECTION ENVINFO subcomponent dump routine
    NULL =================================
    1CIJAVAVERSION JRE 1.8.0 z/OS s390x-64

    I am afraid it could be the cause of my other problems with my applications. Any ideas ? 
    Thank you
    Giovanni

    ------------------------------
    Giovanni Usuelli
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    Attachment(s)



  • 2.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Tue January 05, 2021 09:27 PM
    Hj

    --
    Lahcene





  • 3.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Wed January 06, 2021 09:14 AM
    Might be relevant to the region size that you got less from SSH access via Putty.

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    QI LIANG
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  • 4.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Thu January 07, 2021 07:46 PM
    Do we have the full stdout string? The one pasted in the OP is truncated. Typically along with the javacore there is a system core dump (TDUMP) generated which should be able to tell us more. Judging by the javacore the heap has not been allocated to we failed very early on. Perhaps running with `java -verbose:sizes -version` and showing the output may help. Also what does `ulimit -a` say for the limits in your USS environment?

    ------------------------------
    Filip Jeremic
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  • 5.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Fri January 08, 2021 03:24 AM
      |   view attached
    attached the full core file
    Thank you

    ------------------------------
    Giovanni Usuelli
    ------------------------------

    Attachment(s)



  • 6.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Mon January 11, 2021 01:27 AM
    Hi there,
    it's not a complete javacore. MEMINFO area is empty and the file ends just after it.
    I would do a quick review if you upload a complete one.
    Segmentation errors are linked with memory allocation. I still believe that somewhere in the process there's not enough memory allocation for the JVM.
    I could also be a bug in that particular JVM level but I am less leaned to this possibility.

    Regards,
    Diego.

    ------------------------------
    Diego Cardalliaguet
    Europe GEO Technical Sales
    IBM
    ------------------------------



  • 7.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Mon January 11, 2021 02:00 AM
    From the few lines that can be read in this file there's a thing pulling my attention:

    1CIJAVAHOMEDIR Java Home Dir: /goany/J8.0_64
    1CIJAVADLLDIR Java DLL Dir: /goany/J8.0_64/bin
    1CISYSCP Sys Classpath: 1INTERNAL In-flight data encountered. Output may be missing or incomplete.

    I'd say that the classpath is not propertly set up for the user making java -version. The error comes just right after.
    But it could very well be that there's no room to load the classpath as well (if there's a memory issue).

    ------------------------------
    Diego Cardalliaguet
    Europe GEO Technical Sales
    IBM
    ------------------------------



  • 8.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Mon January 11, 2021 02:03 AM

    Check this:
    https://www.ibm.com/support/knowledgecenter/SSYKE2_8.0.0/com.ibm.java.vm.80.doc/docs/j9_configure_zos_regionsize.html

    Just to ensure there's enough region.



    ------------------------------
    Diego Cardalliaguet
    Europe GEO Technical Sales
    IBM
    ------------------------------



  • 9.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Thu January 07, 2021 07:47 PM

    Hi Giovanni, after logging from putty, can you confirm what ulimit settings you have in your environment with ulimit -a?



    ------------------------------
    Joran Siu
    Advisory Software Developer
    IBM
    Markham ON
    9054136086
    ------------------------------



  • 10.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Fri January 08, 2021 03:22 AM
    ulimit command from OMVS
    # ulimit -a
    core file 8192b
    cpu time 7203
    data size unlimited
    file size unlimited
    stack size unlimited
    file descriptors 64000
    address space 521192k
    memory above bar 500m

    ulimit command from putty

    # ulimit -a
    core file 8192b
    cpu time 20000
    data size unlimited
    file size unlimited
    stack size unlimited
    file descriptors 64000
    address space unlimited
    memory above bar 500m



    ------------------------------
    Giovanni Usuelli
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  • 11.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Thu January 07, 2021 07:47 PM
    Have you compared the results of echo $PATH between the 2 access methods?

    ------------------------------
    Michael Buckley
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  • 12.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Fri January 08, 2021 03:19 AM
    Yes
    they are exactly the same
    Thank you 
    giovanni

    ------------------------------
    Giovanni Usuelli
    ------------------------------



  • 13.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Fri January 08, 2021 01:54 AM
    As Qi Liang says, increase the region for your user it affects both TSO access and SSH or Telnet access. Do not give it less than 256MB. When the JVM is being built in your address space there's no room to allocate the heap.

    ------------------------------
    Diego Cardalliaguet
    Europe GEO Technical Sales
    IBM
    ------------------------------



  • 14.  RE: Java Dump using Putty but not Native OMVS interface

    Posted Fri January 08, 2021 03:29 AM
    May be not important but I don't use SSH to connect to the machine via putty (SSH is not implemented yet)
    I am using rlogin protocol via port 513



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    Giovanni Usuelli
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