Meteor Memory Spike

I been running one of my meteor app on Ubuntu behind an nginx. Once the app starts the memory consumed would be around 800M for my application.

since yesterday, my app just refuses to start and errors out with low memory hitting my VM 1.5G of RAM.
As a short term, I enabled swap to let the app just start.

How do I find the root cause of this sudden memory spike during meteor app start.

I tried the below

  1. i roll back my app to an earlier version
  2. tried my app with fresh db
  3. vm restarts
  4. stopped cron jobs

No luck so far.
My suspect is ubuntu apt-get update, may have updated (may be node or meteor) and screwed up. But I am not so sure. Anyone any thoughts?