If its not collecting and persisting metrics, is it more of a glorified htop?

Not really. htop doesn't visualize historical trends from numerous sources at the same time. Vector also allows us to interface with other metric sources, beyond /proc.

doesn't htop require you to go onto the box? We haven't released our custom pcp modules yet which allow more complex visualizations such as flamegraph generation from perf event sampling.

Yes, exactly - htop is a curses application that shows instantaneous samples of a few system metrics, but it mostly lists processes - this is nothing like Vector at all...

Wait, really?

Why not? Storage is cheap. Do you use something else to get historical visibility into metrics?

Yes, Atlas, which is also open source: http://techblog.netflix.com/2014/12/introducing-atlas-netfli... . Atlas monitors cloud-wide, and stores historical metrics at a one minute granularity.

Vector is for per-instance custom drilldowns. I gave a talk last year where I showed how they both fit together: http://www.brendangregg.com/blog/2014-09-27/from-clouds-to-r...

Got it... and thank you Brendan!

I think the reason is they have a bunch of ephemeral hosts which they don't want to put in a central web interface or collect statistics on. They are only interested in getting some insight as to what went wrong with this host so they can fix it in the future.

Grafana, Graphite, StatsD, Skyline.

pcp is happy to collect & persist metrics; vector just doesn't happen to render them. pcp offers other ways to interact with live or archive-saved data, including other webapps.

Neither does collectd, it just gathers and transmits the data to an endpoint you specify. It's also quite lightweight (once you address the memory leaks, at least).