Posts tagged "dtrace"

In about a week, on November 9th, 2011, the long-awaited final version of Solaris 11 will be launched. If you happen to be near New York that day (and assuming there’ll be no power outages), you’re invited to join the official Solaris 11 launch party!

Solaris 11 has been in the making since 2005, when Solaris 10 was launched. In fact, every major Solaris release is just a fork of the ongoing Solaris development train, so the very first uber-pre-release of Solaris 11 was actually generated only weeks after Solaris 10 hit the shelves.

Since then, Solaris 11 (or: Project Nevada as it was called) has seen a lot of OS history: An open source adolescence called OpenSolaris, growing adoption and community work, a broad range of ground-braking new features, long overdue re-writes, brand new concepts, controversial discussions, a major acquisition, rules changed and rules kept, siblings and offsprings, lots of investments, entire companies built on top of its source code, generations of processors and hardware, lots of systems in production, the Cloud and what not.

And all that before it was even born. Quite an achievment, eh?

First of all: Apologies for not posting for a long time. The reason? I was having too much fun with node.js and the Joyent Cloud :).

What started as a small experimental hack turned quickly into an exciting new pet project involving the good old Mandelbrot Set, as a web service, running in the Joyent cloud, programmed in node.js.

But first things first: Let’s take a look at node.js as a language and programming model, at the Joyent Cloud and how it relates to Solaris and finally some details on how the picture you see was rendered inside the Joyent Cloud, including an interactive Mandelbrot Set explorer you can play with now, written as a web app.

In the last couple of posts, we used DTrace to notify our media servers and perfected our script a bit.

But the script is still not ready to be used on our home servers yet: It requires manual start and stop, not quite the service oriented automatism we’re used to in the Oracle Solaris world.

The next step is to wrap our DTrace script inside a Service Management Facility (SMF) service, then wrap everything into a shell script that will easily install or remove the service whenever we need it.

A few weeks ago, we discussed using DTrace for automatically updating media servers when you upload new content.

Yesterday though, I discovered that my D script didn’t work any more. I uploaded new songs to my home server, and expected the music daemon to re-scan the music directory, but nothing happened.

That teached me an important lesson about DTrace, and here’s what I learned:

Before we continue with our Home Server Scripting Series, let’s throw in a simple but useful DTrace hack.

One of the most typical uses for a home server is to serve music or videos to home entertainment equipment. In my case, I’m using the Firefly Media Server (no link, fireflymediaserver.org no longer exists) to serve music to my Roku Soundbridge and Mediatomb (no link, page no longer exists) for videos.

The Media Server Update Problem

Whenever I upload new music or videos to my OpenSolaris home server (typically by rsync-ing my laptop home directory), both Firefly and Mediatomb need to be restarted so they detect that new files are sitting in their directories, waiting to be served.