Java what is -Xms and -Xmx parameter?
By:Roy.LiuLast updated:2019-08-11
In Java, -Xms set initial Java heap size, while -Xmx set the maximum Java heap size.
1. Some java -Xms -Xmx examples :
# Start with 128MB of memory, and allow the Java process to use up to 1024MB of memory. java -Xms128m -Xmx1024m
# Start with 256MB of memory, and allow the Java process to use up to 4G (4096MB) of memory. java -Xms256m -Xmx4g
2. The default initial and maximum Java heap size is allocated based on this ergonomics algorithm , also read this article – Find out your Java heap memory size
3. If the Java process has exceeded the -Xmx maximum Java heap size, the popular java.lang.OutOfMemoryError will be thrown.
4. For other options, run this java -X
> java -X -Xbatch disable background compilation -Xbootclasspath/a:<directories and zip/jar files separated by ;> append to end of bootstrap class path -Xcheck:jni perform additional checks for JNI functions -Xcomp forces compilation of methods on first invocation -Xdebug provided for backward compatibility -Xdiag show additional diagnostic messages -Xfuture enable strictest checks, anticipating future default -Xint interpreted mode execution only -Xinternalversion displays more detailed JVM version information than the -version option -Xloggc:<file> log GC status to a file with time stamps -Xmixed mixed mode execution (default) -Xmn<size> sets the initial and maximum size (in bytes) of the heap for the young generation (nursery) -Xms<size> set initial Java heap size -Xmx<size> set maximum Java heap size -Xnoclassgc disable class garbage collection -Xrs reduce use of OS signals by Java/VM (see documentation) -Xshare:auto use shared class data if possible (default) -Xshare:off do not attempt to use shared class data -Xshare:on require using shared class data, otherwise fail. -XshowSettings show all settings and continue -XshowSettings:all show all settings and continue -XshowSettings:locale show all locale related settings and continue -XshowSettings:properties show all property settings and continue -XshowSettings:vm show all vm related settings and continue -XshowSettings:system (Linux Only) show host system or container configuration and continue -Xss<size> set java thread stack size -Xverify sets the mode of the bytecode verifier
From:一号门
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