Making sure NODE_OPTIONS --max-old-space-size is working
To get heap size in megabytes pls use
const v8 = require('v8')
v8.getHeapStatistics().total_available_size / 1024 / 1024
Example 1
node --max-old-space-size=256
v8.getHeapStatistics().total_available_size / 1024 / 1024
284.47106170654297
Example 2
node --max-old-space-size=512
v8.getHeapStatistics().total_available_size / 1024 / 1024
544.9713745117188
Example 3
export NODE_OPTIONS=--max-old-space-size=1024
node
v8.getHeapStatistics().total_available_size / 1024 / 1024
1065.4709014892578
So, as we can see, both command line arg and env variable NODE_OPTIONS work.