Looking for Zing? The Azul Zing Virtual Machine is now Azul Zulu Prime Builds of OpenJDK and part of Azul Platform Prime. Learn more.
When generating crash associated files, you can use an option,
-XX:+DumpMiniCore, that creates significantly smaller Azul Zulu Prime Builds of OpenJDK (Azul Zulu Prime JVM) 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 Azul Zulu Prime JVM core files do not include application objects stored in the Java heap.
Time required to produce a Azul Zulu Prime JVM 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 VM option 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 Azul Zulu Prime JVM crashes.
-XX:+DumpMiniCoreoption is specified, a core file, that does not include the application objects stored in the Java heap, is created if Azul Zulu Prime JVM crashes.
-XX:DumpMiniCoreLevel=<x>options are specified, a core file, that includes the specified information, is created if Azul Zulu Prime JVM crashes.