

Using DTrace to debug a Node Knockout winner - bcantrill
http://dtrace.org/blogs/brendan/2011/09/26/observing-observer-a-cloud-analytics-case-study/

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eis
DTrace is a powerfull tool, no question. And the easy to use web interface
makes SmartOS pretty compelling to try out.

However all this debugging could have been avoided if the webserver logged in
its error log that the socket limit has been reached...

~~~
dmpk2k
In retrospect it's obvious. Unfortunately, most software is not so thoroughly
logged; there isn't enough time, and people make mistakes.

~~~
eis
Absolutely. You can't avoid people making mistakes - it's human.

But software that does not do propper logging exactly leads to spending time
on debugging that could have been avoided. It's saving time by not adding
logging that causes wasted time in the end :)

Usually tools like DTrace are used to find hot-spots, points of contention,
places which block other stuff and so on.

Not to pull a Cpt. Hindsight but this one could have been avoided if the
software was crafted a bit more carefully. I'm not sure if the proxy needed to
be written using NodeJS, there are plenty of existing proxies that work just
fine and give you exactly the errors in the log that you need for 99% of
cases.

Just saying there is a lesson to be learned here.

------
Fuzzwah
I am looking forward to the "Observations of Observing Observer" article which
is sure to follow, as it appears that images in this blog post have been 503'd
due to downtime or capacity problems!

