Although it is nice that there is work arounds for the DNS spikes with either nscd or the in-process DNS cache, i think the DNS spikes are a symptom of a whole different issue.

I think we can safely assume that each DNS lookup is corresponding to one attempt at establishing a TCP connection then there is some code somewhere that spawns an awfull lot of short lived connections instead of reusing / pooling them - with all the issues that follows in that area (insufficient ulimit NOFILE, connections in TIME_WAIT/exhausting of client ports etc)

@lematz
In the first picture of "hostname and dns configuration":
It doesn't look like you have any double colon '::' in the first 2 entries but you have them in all fields on the last picture

When I (re)build on my 3 GB vm i use this before in order to keep nodejs at bay

export NODE_OPTIONS='--max-old-space-size=3072'

And then it runs smoothly