Interpreting a Java dump

This section gives examples of the information contained in a Java™ dump file and how it can be useful in problem solving. The Java dump file contains sections separated by eye catcher title areas to make it easier to read.

The first such eye catcher is shown as follows:

NULL           -------------------------------------------------------------
0SECTION       ENVINFO subcomponent dump routine
NULL           =================================

Different sections contain different tags, which make the file easier to parse for performing simple analysis.

You can also use DTFJ to parse a Java dump. For more information, see Using the Diagnostic Tool Framework for Java.

An example tag (1CIJAVAVERSION) is shown as follows:

1CIJAVAVERSION JRE 1.8.0 Linux x86-32 build 20121117_128845 
(pxi3270-20151120_01)

Normal tags have these characteristics:

• Tags are up to 15 characters long (padded with spaces).
• The first digit is a nesting level (0,1,2,3). Nesting levels might be omitted, for example a level 2 tag might be followed by a level 4 tag.
• The second and third characters identify the section of the dump. The major sections are:

  CI

  Command-line interpreter

  CL

  Class loader

  LK

  Locking

  ST

  Storage (Memory management)

  TI

  Title

  XE

  Execution engine

• The remainder is a unique string, JAVAVERSION in the previous example.

Special tags have these characteristics:

• A tag of NULL means the line is just to aid readability.
• Every section is headed by a tag of 0SECTION with the section title.

NULL           ------------------------------------------------------------------
0SECTION       TITLE subcomponent dump routine
NULL           ===============================
1TICHARSET     UTF-8
1TISIGINFO     Dump Event "vmstart" (00000001) received
1TIDATETIME    Date: 2016/11/20 at 17:03:57 
1TIFILENAME    Javacore filename: /home/user1/javacore.20141120.170357.6226120.0001.txt
1TIREQFLAGS    Request Flags: 0x81 (exclusive+preempt)
1TIPREPSTATE   Prep State: 0x6 (vm_access+exclusive_vm_access)
NULL           -------------------------------------------------------------------
0SECTION       GPINFO subcomponent dump routine
NULL           ================================
2XHOSLEVEL     OS Level : Linux 2.6.18-238.5.1.el5
2XHCPUS        Processors -
3XHCPUARCH       Architecture : x86
3XHNUMCPUS       How Many : 4
3XHNUMASUP       NUMA is either not supported or has been disabled by user