Epilog Helix 24 Laser Engraver/Cutter

I took the two hour class on Wednesday night with three other participants.  The class was taught by Laura Mapping, who has been a laser-working enthusiast for about three years.  The class covered:

• Shop etiquette
• How the machine works & basic operations
• Safety
• Appropriate materials

Everyone in the class got to take turns trouble-shooting and optimizing a design that we “lased” onto some cardboard, showing how the dots-per-inch, speed, and power settings affect the final outcome.  At the end of the class we were given souvenir dog-tags and allowed to etch whatever we wanted onto them.

I really enjoyed the class, the machine was neat and the instructor was great.  Once Clio and I finally find our permanent location in the bay area, I’ll probably get a membership at the Tech Shop so I can go back and play with the laser and maybe learn about some of the other machines.

The book covers 4 main topics:

• Stability
• Capacity
• General Design Issues
• Operations

In most of the sections the author breaks his advice down into an introduction (with a real example showing a problem), a set of anti-patterns that encourage the problem and a set of patterns to help  software cope with the various stresses placed on it and make it manageable.

The book stays at a relatively high level of discussion and is easy to follow.  If you are looking for lots of low-level coding examples you will be disappointed, but I think the book offers good advice that can be consumed by a wide range of people ranging from developers, to system administrators, and to project managers.

Last year I was involved in a project that struggled with a lot of the issues mentioned in this book and I think that hundreds of thousands of dollars and countless hours of stress and frustration could have been saved if this book had been required reading at the start of the project.

I recommend this book to anyone involved in developing or operating software services, or managing the people that do.

]]> http://www.williamhathaway.com/wordpress/2010/01/21/thumbs-up-for-release-it/feed/ 0 http://www.williamhathaway.com/wordpress/2010/01/14/zfs-presentation/ http://www.williamhathaway.com/wordpress/2010/01/14/zfs-presentation/#comments Thu, 14 Jan 2010 14:40:22 +0000 William Hathaway http://www.williamhathaway.com/wordpress/?p=527

Photo by John @ ThinkHole.com

On Tuesday night I gave a presentation on ZFS to the Central PA Linux User Group. Since the audience was a Linux user group, I wasn’t expecting too many in the crowd to be familiar with ZFS, but I was pleasantly surprised that about 40% of the ~ 20 people in attendance had used ZFS in some capacity. If you are already a seasoned ZFS user, I would highly recommend Richard Elling’s ZFS presentation which he uses in his day-long tutorials.

A friend of mine’s son, Alex, has recently accepted a software development job at a financial trading company.  He is starting his final semester of school, so he won’t begin working at the company for another 4-5 months.  When I was over visiting at their house last week, Alex showed me a small stack of  books that the company had sent him.  The books covered  a mix of technical and business topics that would help him build up an understanding of the software tools, development philosophies, and business concepts specific to the organization so that when he arrived at work he will be productive much quicker.

I think this is a fantastic investment by the company, and should be considered by organizations hiring for any but senior positions.  You obviously don’t want to overwhelm new hires with an onslaught of 10,000 pages of recommended reading, but having a small package from Amazon show up at their door containing a few books most appropriate to their position and your culture is a great way to help new hires get up to speed, even before they hit the door.

On Monday I attended a tutorial by Richard Elling on ZFS: A Filesystem for Modern Hardware.

On Tuesday I attended two tutorials.  The first was Jacob Farmer’s Disk-to-Disk Backup and Eliminating Backup System Bottlenecks.  The second was Tom Limoncelli’s Design Patterns for System Administrators.

Unfortunately on both Monday and Tuesday I had to spend a significant amount of time on conference calls helping to troubleshoot some work related issues, but the time I spent in all 3 sessions and viewing their materials was helpful.  I would definitely recommend attending tutorials by any of the 3 people above if they are teaching a topic of interest to you.

On Tuesday night I attended some (Open)Solaris birds-of-a-feather sessions.  There were a few times that people in the crowd were being belligerent towards a speaker (mostly complaining about the difficulty of finding information of various types), even though the speaker certainly had no sway over what the person in the crowd was upset about.  I don’t care how much money your company spends with a vendor, there is never a reason to be rude.   David Miner gave a talk about whats coming in Solaris.next and Ben Rockwood gave an entertaining and informative presentation on ZFS in the Trenches.

I was lucky enough to get a chance to talk with David Miner over a quick lunch later in the week and talk about the new opportunities and challenges with the OpenSolaris installation technologies.

On Wednesday through Friday I attended a mix of presentations, met with a bunch of vendors, and also sat in some of the ‘Guru is in’ sessions and talked with a number of conference attendees.  The highlights for me were:

• Werner Vogel (CTO of Amazon) gave a fascinating talk on the history of Amazon’s IT philosophy and infrastructure and how they evolved from a humble internal IT shop to adding a business which is the dominant  cloud computing provider.
• Elizabeth Zwicky’s talk on “Searching for Truth, or at Least Data: How to Be an Empiricist Skeptic”
• Bryan Cantrill’s talk on “Visualizing DTrace: Sun Storage 7000 Analytics”
  
• Talking with the folks from Splunk (awesome log searching analysis tool)

I just sent in my registration request for The Amaz!ng Meeting 7.  I’ll also be attending Dr. Steven Novella’s Science Based Medicine pre-conference the day before and catching Penn & Teller’s show on Saturday night.

• How bloodletting was an extremely popular medical practice all the way from the ancient Greeks up until the last 150 years or so (and has some specific uses now).  George Washington’s doctors drained about half of his blood in the two days before he died in a misguided attempt to help him.
• The first documented precursor to the clinical trial was to test various cures for scurvy (and the results ended up giving a huge naval advantage to England).  If you were a navy sailor in the 1700s you were much more likely to die from scurvy than fighting.
• Florence Nightingale‘s desire to make hospitals more hygienic saved thousands of lives and her excellent statistical background helped her prove the value to a skeptical medical community.

Pros

• I think the class was helpful in incorporating some performance concepts that I knew about but hadn’t fully baked into my mental model.
• A few of the lab exercises were really good.
• I got to use SWAT (a disk and tape workload analyzer) again and it definitely seemed a smoother experience than when I used it a about a year and a half ago. I’ll definitely put it my bag of tricks.  Follow Henk’s blog to stay up to date.

Cons

• There was a lot of material to cover, especially for students without some level of a computer science background
• Some of the labs didn’t work
• The books were last updated in 2006 and while it had some modern touches (DTrace scripts were sprinkled in a few times), you could tell it wasn’t a modern course.  I think most of the material was probably written in the late 90s and incrementally updated.
• The instructor wasn’t good about letting students know what parts of the book contained practical advice that they would use frequently versus other aspects which were much more theoretical.
• The instructor wasn’t following the non-OS tools mentioned in the book.  For example, SWAT and vdbench are available to all users now (previously it was just Sun employeers and resellers).

Overall Rating
Based on my experience, I wouldn’t give a recommendation for people to take this course.  I’m sure there are some instructors that deliver more value than the one I had, but I also think there is much stronger material out there now than the aging textbook.  There was a lot of material to cover, and for people without some level of computer science background, it seemed tough.  Covering things such as the difference between a “direct-mapped” versus a “set-associative” cache seemed not to be a good use of time when there was still a lot of student misunderstandings about the basic info provided by tools such as vmstat.

What I Recommend

I think a better use of time is to get a copy of the excellent Solaris Performance and Tools book (and potentially the Solaris Internals book as well) and be prepared to spend some time reading through it and trying the tools out on a test machine that has some load on it. Also, take a gander at the Solaris Internals Wiki, which has a lot of great information about performance and tuning of Solaris for a wide variety of sub-systems and situations.  For a quick tour around Solaris 10 performance and observability, check out Jim Mauro’s latest presentation.

I had blogged awhile ago about a UC Berkley course informally titled “Physics for Future Presidents” that I had listened to on my iPod and found really enjoyable.  The professor has just released a book version meant for the casual reader (you don’t need to be a physics egghead at all).  I found my copy when I got home on Friday and am about 1/3 through it.  If you have any interest in learning about things that a “future president” should know about terrorism, energy, nukes, space, and global warming etc… to help make policy decisions, this book is a fantastic read, I’d highly recommend it.

Amazon Link

If you are someone I see on a regular basis and want to borrow my copy, just let me know.  I’ll be done with it by Tuesday at the latest.