Since v4.3.0 Karaf does not support the environment variables to set max/min heap memory (JAVA_MAX_MEM/JAVA_MIN_MEM): KARAF-6887, KARAF-7071

However, odlparent still applies a patch to add this to setenv:

if [ "x$JAVA_MAX_MEM" = "x" ]; then
    export JAVA_MAX_MEM="2048m"
fi

This gives a wrong impression that max heap size is set to 2GB by default and JAVA_MAX_MEM is a valid configuration option.