Setting JVM heap start and max sizes, -Xms and -Xmx, for executors

[Mulugeta Mammo]

Hi,

I'm running Spark 1.4.0, I want to specify the start and max size (-Xms and
Xmx) of the jvm heap size for my executors, I tried:

executor.cores.memory="-Xms1g -Xms8g"

but doesn't work. How do I specify?

Appreciate your help.

Thanks,