Charles Engelke’s Blog

July 23, 2011

Pictures from our Arctic Circle Cruise

Filed under: Uncategorized — Charles Engelke @ 12:02 pm
View of Longyearbyen, Norway from above

Overlooking Longyearbyen

Now that I’m home and have decent Internet access, I’ve posted pictures from our Celebrity Constellation cruise to the Arctic Circle. We visited three Norwegian ports north of the Arctic Circle: Leknes (in the Lofoten archipelago), Honningsvåg (near the north cape and the Gjesværstappan bird sanctuary), and Longyearbyen (above, on Spitsbergen in the Svalbard archipelago).

We also visited two Norwegian ports south of the Arctic Circle: Bergen and Ålesund (where we took a bus tour inland along the Path of the Trolls). And we spent several days before the cruise in Amsterdam, from which we took a day trip to the Hague.

It was all beautiful, and now I have an idea of the difference in degree between different arctic areas. All our visits were to seaside areas, but Leknes (at 68° 08′ N) is coastal and lush…

Leknes

Leknes

… while the North Cape area around Honningsvåg (at 70° 58′ N) is much more sparsely vegetated…

House near Honningsvåg

House near Honningsvåg

… and Longyearbyen (all the way up at 78° 13′ N) is very severe, not only lacking trees but really without any plants more than few inches tall…

Guide at Longyearbyen

Guide at Longyearbyen

… and with polar bears, which is why our guide was armed with a rifle. Unfortunately, we didn’t get to see a polar bear; fortunately, we didn’t get attacked by one, either.

July 5, 2011

Amsterdam Art in the Street

Filed under: Uncategorized — Charles Engelke @ 3:53 pm

Our hotel here in Amsterdam is on Apollolaan, which is part of Artzuid – International Sculpture Route Amsterdam. We were surprised when we got off the tram on the way in from the airport to encounter a man riding a giant golden armored turtle:

Scupture

Searching for Utopia - Jan Fabre

As we continued the one-block walk, we passed by what seems to be an elephant on stilts:

Sculpture

Space Elephant - Salvador Dali

I really liked this kinetic sculpture. It only runs for five minutes each hour, but we just happened by as it was going:

Sculpture

Heureka - Jean Tinguely

I’ve got a one-minute movie of that sculpture, too. Maybe I’ll post it, if I ever figure out YouTube.

This afternoon we tried a different kind of Amsterdam art: microbrewed beer from a 300 year old windmill, Brouwerij ‘t IJ:

Windmill

Brouwerij 't IJ at Windmill

I can confirm that at least three of their beers, especially the Columbus, are also works of art.

July 1, 2011

Relative Performance in Amazon’s EC2

Filed under: Uncategorized — Charles Engelke @ 11:58 am
Tags: , ,

I’ve been using Amazon’s Elastic Compute Cloud for several years now, but a lot more lately. And one thing that has always confused me is the relative benefits of using Elastic Block Store (EBS) versus instance store.  I’ve seen some posts on this, but they all set up sophisticated RAID configurations. What about some simpler guidance for a regular developer like me?

Well, I don’t have the answers, but I have a little bit of new data. I’m updating a site that starts by loading a 1.25GB flat file into MySql, then creating three indexes, then traversing that table to create a second, much smaller table.  Dealing with those 10 million rows is pretty slow, so I decided to see what difference it made using EBS or the instance store. While I was at it I tried different size machines. The results, shown in minutes to complete the task, are summarized in the table below:

Size  EBS  Instance
t1.micro 635
m1.large 56 66
m2.xlarge 47 49
m2.4xlarge 42 40
c1.xlarge 49 49

The t1.micro machine size is only available in EBS, and it got about 90% of the way through (finished creating all three indexes) then died.

This seems to show that (for this kind of operation) EBS performed noticeably but not enormously better than the instance store, but the difference shrank as available memory increased. Also, “larger” machines didn’t help much once there was enough memory available. Not surprising, since this is a single-threaded operation.

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