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When generating crash associated files, you can use an option,
-XX:+DumpMiniCore, that creates significantly smaller Zing core files. To adjust the size of the core file, use this option with the
-XX:DumpMiniCoreLevel=<x> option. Where
<x> specifies the information that is included in the mini core file.
When you use this option:
- Generated Zing core files do not include application objects stored in the Java heap.
- Time required to produce a Zing core file or core file bundle is reduced.
To further adjust the amount of data that is included in a mini-core file, include the option,
<x> is in
- Level 0 (the current default) includes page infos and audit records
- Level 1 includes marking information and the card tables
- Level 2 includes trampolines, forwarding hash tables, preallocated pages etc.
- Level 3 includes the heap mirror pages
- Level 4 includes the object heap itself
The mini-core file
-XX:+DumpMiniCore option requires ZST 5.7.5 or later and ZVM 5.10.x or later. The mini-core file level option,
-XX:DumpMiniCoreLevel=<x>, requires ZST 5.7.11 or later and ZVM 15.05.0.0 or later.
- The default value of
DumpMiniCoredepends on the
If Xmx >= 40g, the default is true (enabled);
Otherwise the default is false (disabled).
- The default value of
If the option is specified and either the ZST version or ZVM version is not compatible, a message is issued.
If the ZST version supports the
-XX:+DumpMiniCoreoption, but the ZVM version does not, an
Unrecognized VMoption warning is printed to STDERR. For example:
<my dir>/jdk6/x86_64/product/bin/java -XX:+DumpMiniCore -version
Zing 64-Bit Tiered VM error: Unrecognized VM option '+DumpMiniCore'
Could not create the Java virtual machine.
If the ZVM version supports the
-XX:+DumpMiniCoreoption, but the ZST version does not, a warning message is issued. For example:
/bin/java -jar -XX:+DumpMiniCore -version
Zing VM Warning: -XX:+DumpMiniCore is not supported by this ZST (found API version 0x5e, requires API version >= 0x5f)
java version "1.7.0-internal-zing_188.8.131.52.dev"
Zing Runtime Environment for Java Applications (build 1.7.0-internal-zing_184.108.40.206.dev-b25)
Zing 64-Bit Tiered VM (build 1.7.0-zing_220.127.116.11.dev-b501-product-azlinuxM-X86_64, mixed mode)
Include the option
-XX:+DumpMiniCore, and optionally,
-XX:DumpMiniCoreLevel=<x>, with your Java launch command.
Some failures cannot be effectively diagnosed with a mini-core file. In this case, Azul support may request that you try to reproduce the failure and produce a full-sized core file, by removing -
XX:+DumpMiniCore from your Java launch command.
-XX:+DumpMiniCoreoption is not specified, a full core file, including the application objects stored in the Java heap, is created if Zing crashes.
-XX:+DumpMiniCoreoption is specified, a core file, that does not include the application objects stored in the Java heap, is created if Zing crashes.
-XX:DumpMiniCoreLevel=<x>options are specified, a core file, that includes the specified information, is created if Zing crashes.
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