Amazon Web Services has recently released their PHP SDK. It’s not the most well documented library out there but it does make doing a lot of things on AWS a lot easier. I’ve been working on a few small projects as proof-of-concepts for scalable web applications that can run off a regular web server but leverage the cloud for storage and extra compute capacity.

One component I’ve spent a few hours on working out has been a monitoring component. Basically, a script runs regularly and collects a few statistics (e.g. S3 bucket size), storing all the information into a SimpleDB domain. Anyway, what it does isn’t relevant - the point is that it stores a load of data roughly resembling a logfile using SimpleDB. That bit is all very easy to architect and develop.

The hard part is retrieving this information. I’m planning to use the Google Visualisation API to generate some cool graphs, and I was planning to create a simple PHP script that would basically extract some log data and output it to CSV. This is where the roadblock is. Amazon SimpleDB result sets are restricted to the lesser of 100 rows or 1 MB. Queries with larger result sets are paged, and each result set will contain a token which can be supplied on a subsequent request. Sounds simple.

But the SDK has no method to retrieve the token from the request. The samples don’t mention it and the API reference is just a JavaDoc which doesn’t include much detail. (Although it at least does tell you how to pass the token on the next request). Without a way around this, the PHP SDK is just about useless for SimpleDB in most use cases where you’d use SimpleDB over a traditional RDBMS like MySQL.

It took some analysis and reverse engineering and eventually I found out how to get to the NextToken value in the response. Here’s a code snippet. I just realised I set this blog up for photography so I never bothered to put in a decent code highlighter so bear with me.

$sdb = new AmazonSDB();

$opt = array();
$query = “SELECT * FROM `opengal_monitor`”;

do {
// Send query to SimpleDB
$results = @$sdb->select($query,$opt);

// The value for NextToken is found here
$opt['NextToken'] = $results->body->SelectResult->NextToken;

// Remove all line breaks or subsequent queries will fail
$opt['NextToken'] =
ereg_replace(”/\r|\n/”, “”, $opt['NextToken']);

// Put the items in an array
$items = $results->body->Item();

// Do Stuff

} while ($opt['NextToken']);

And that’s it! Based on this, it would be a trivial task to overload the CFResponse class for SimpleDB Select operations and provide a method that would return the NextToken value in its correct format (i.e. no linebreaks).

I was one of those senseless individuals who decided to travel north into the only Australian city that foreigners could name. It was a very early start. Here’s a photo of me trying hard to not look tired.

View from the West Gate Bridge

For anyone who hasn’t had to use it, Avalon Airport is quite a dump. It’s far from everything (I don’t count the western suburbs) and there are no facilities there. But Jetstar flights are very cheap and so are train tickets from the nearby train station. However it does take longer to travel from Avalon to Melbourne’s south-eastern suburbs than it does to get from Avalon to Sydney.

Eventually we arrived in Sin City where we waited to check in at the Swissotel. Given that it was about 11am, our room wasn’t ready yet. Waited in the fancy foyer for a while until the room became available. Why are hotel corridors always so tacky?

Our view mainly consisted of the base of the Sydney Tower.

Sydney sure uses a lot of sandstone or sandstone-coloured concrete.

After a short bit of recovery, we explored Sydney a bit. Everyone was still tired from the previous night so not much was achieved. It also explains the noticeable shortage of photographs as you have probably noticed by now.

George and Market Streets

Monorails are an epic fail when it comes to actually transporting people, but I guess they sounded like a cool idea back in the 1980s. We ended up walking around the immediate vicinity of the hotel such as the Queen Victoria Building which is quite like the Melbourne Central shopping centre.

QVB in HDR

Nothing of note really happened in these few hours. I really need to go back up to Sydney for a bit longer next time and with a local to show me around. We did find a pretty nice steakhouse though, which was to be the last big tasty steak for quite some time.

On the way, we got to make a token crossing of the coathanger on the way there and passed through Circular Quay which has one of the most picturesque railway stations in an urban environment in Australia.

Circular Quay station

Oh yeah, later that night, we visited a convenience store where a fight was about to break out because some drunk muzza was complaining about a mobile phone recharge card that didn’t work.

The setup basically involves my Nikon D80 with an SB-800 attached, plus a Sunpak 555 connected to the SB-800’s sync port. There is nothing else fancy about it. The white background is just a pile of A3 paper spread out over my desk.

The most confusing part is the Sunpak flash. Mine is second-hand and there is very little documentation regarding how to actually operate it and whether it plays nice with my other gear. Well, it does. It has two ways of syncing to a camera: it has a weird proprietary sync port which requires a cable that I can’t find anywhere, or via hot-shoe or a regular sync cable using the STD-1D module. That’s the cheapest module and is a lot cheaper than the various TTL modules.

Anyway, I point one flash at the subject and the other at the ceiling. Then it’s just a matter of trial and error to get the flash exposure right. After a few minutes, I was producing great quality product shots which I never thought would have been so simple. The only key is to overexpose the flash a bit so that the overlapping edges of the paper blow out and disappear while keeping the subject properly lit. Everything is in manual mode.

Here are some samples. Sorry, I’ll find some more interesting (and a greater variety of) subjects next time.

Calculating flash exposure

• Shutter speed is totally irrelevant because all light is coming from the flashes.
• Aperture can be freely used to adjust depth of field and overall exposure, no need to worry about background exposure because there is none.
• ISO - no need to explain that
• Flash exposures - normally I start at max for both and reduce them until I get a good balance. The direct (non-bounced) flash can be turned down a bit to reduce shadows.

This latest iteration of the gallery is only able to display pictures and very crudely search the keywords gleaned from the metadata. But that’s all I need.

There isn’t really any home page to direct you to, so you’ll just have to do a keyword search for Melbourne. The list of keywords is displayed at the bottom of the search page.

Microsoft has all kinds of logical reasons behind making things not work.

Meanwhile, check out some of these other blogs:

Euphoric Trance

Rusty - Just Another Blog

Cameland

Click on the photos to open a larger version.

Here’s the panorama I took, spot the light pollution.

Close-up of the city skyline, 34km away using a 200mm lens.

Same photo, cropped and annotated:

(crappy picture yes, but obviously all my good cameras are in the photo)

Left to right:

Nikon AF Nikkor 70-300mm f/4-5.6G
Nikon AF Nikkor 28-80mm f/3.3-5.6G

Nikon D80, with:
Nikon AF-S DX VR Nikkor 18-200mm f/3.5-5.6G IF-ED

Nikon F90X, with:
Nikon SB-600 (broken locking pin, permanently attached), and
Nikon AF Nikkor 50mm f/1.8D

Nikon D70, with:
Tokina 12-24mm f/4 DX

Bronica Zenzanon 75mm f/2.8 EII
Sunpak Auto 555 (need to get coupling modules for Nikon/Bronica)

Bronica ETR-SI, with:
Bronica Zenzanon 150mm f/3.5 EC
220 Roll Film Holder

Spare 200 roll film holder

Polaroid 360.

35 year old packaging yay:

30 year old batteries ftw:

Fresh batteries, $20 of them.