Problems running Java Application on Docker

Question

I have the following problem.

I created a container with 1GB of memory and 16GB of Swap, I am using Oracle JDK 8 Update 171 (64 bit) with S.Debian 9.

Set the Java_opts parameters for the JVM to read the CGROUPS.

The container is climbing correctly with the parameters I passed. Inside the container I can climb my Springboot application twice (02 processes), one with 08GB (XMS and XMX) and the other with 7GB (XMS and XMX) without problems.

From what I understand in the container I have 01GB RAM + 14GB SWAP = 15GB total.

But when I try to climb only an application with 9 or 10GB (XMS and XMX), the application does not over and generates me the hs file... stating that it cannot allocate memory.

How is it possible to climb 02 processes with 15GB (8+7), but not over 01 process with 09GB????

I have tried to increase the RAM to 10GB and 6GB swap. I’ve set up reserved memory, but nothing worked.

I tested the same application on a Debian outside the container, Debian has 1GB (RAM) and 16GB Swap and managed to climb it with 12GB XMX.

Can you help me?