Dan Milstein

Recent Posts

Post-Mortems at HubSpot: What I Learned From 250 Whys

At HubSpot, for the past two years, we've modeled our post-mortems on Eric Ries's 5 Whys.  When we started, I served as the facilitator for basically all of them -- over time, we've added other folks into that role.

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The Self-Referential, Executable svn Commit Message

A month or so back, the HubSpot svn repo began to approach commit number 50,000.  And, amid the idle banter about how best to celebrate the event, my friend and scrum team-mate Owen J Raccuglia, aka OJRac, aka Juice, quietly went and coded up a deviously clever hack, which, a brief bout of svn commit sniping later, became our commit 50K.

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Who Loves the Magic Undocumented Hive Mapjoin? This Guy.

So, I've got this nice Hive join statement, joining a tiny little partition from one table against a sizable set of partitions from another.  And I'm running it, and it's taking a while.  And I can tell,from looking at the job, that it's doing the join reduce-side --meaning, it's generating the cross-product in the mapper, and then sending it over to the reducer to filter it down. 

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Hadoop World, NYC 2009

On the train back from New York, where I just caught the very first Hadoop World, NYC conference, along with a few HubSpot friends (Steve Laniel, Owen Raccuglia, Andy Novikov).

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My Best Moment at Work, Lately

Working on our spiffy new Analytics app (soon to be released to customers), ran into a severe bottleneck getting our summarized data out of Hadoop and into MySQL (which we use to hold, essentially, a bunch of precomputed reports).

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Bruce Schneier and xkcd walk into a bar...

A somewhat astonishingly good explanation of AES via stick figures (yep, stick figures):

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