Implication on memory usage if run JVM without any options?

Question

We have 64-bit Oracle JRE 8 and our application start as:

java -jar C:\path\to\app.jar

How JVM does uses memory in that case (when you do not set -Xmx and other options)?

Answer 1

So the max memory consumption limited even in 64-bit machine by default... But this number differs for same JVM but different hosts.

For openjdk and oracle jvms this is governed by the MaxRAMFraction option, which under 64bit defaults to 4, ie 25% of physical memory.

Answer 2

我不记得是对的，但是据我所知，如果您不指定-Xmx或-Xms，jvm将不使用超过25％的RAM