Thursday, 22 May 2014
I'll be talking about two distinct systems. The first is our proprietary system for managing online photo publication. Spotlight has been publishing photographs in one form or another since 1927, and so our current system is the latest in a long, long series of incremental developments - from acid-etched brass photograph plates, to lithographic bromide machines, to industrial film scanners and ImageMagick. Photography is an absolutely fundamental part of the creative casting process, and we reached a point a few years ago where our web servers were spending 60%-70% of their CPU time rendering photographs. Working within the limitations of our legacy systems, we developed a distributed thumbnailing and caching system that delivers the same results with a fraction of the processing overhead. I'll discuss how we used NServiceBus to work around those limitations, the architectural and operation challenges we faced building and running this system, and some of the lessons we learned when, a year after deploying it into production, we had to migrate this system from onsite hosting to a private cloud.
The second is an online audio/video upload and publishing system. Working with online video offers a unique set of challenges - dozens of incompatible file formats, massive file uploads, unpredictable analysis and encoding jobs. We built and deployed a system that satisfied these requirements whilst offering an intuitive, responsive user experience, and in this talk I'll cover the high-level architectural approach that enabled this. We'll look at how we used NServiceBus to decouple the 'heavy lifting' components of the application from the customer-facing user interface components, and some of the lessons we learned deploying a distributed NServiceBus application in an Amazon EC2 hosting environment.
NSBCon is at SkillsMatter here in London, on the 26th and 27th of June 2014. I'll be speaking alongside a great panel of .NET and distributed systems experts, including Udi Dahan, Ayende, Greg Young, Andreas Ohlund and many others. Follow @NSBCon on Twitter for more updates, and sign up at SkillsMatter if you're interested.
Friday, 31 January 2014
Forms authentication in .NET has a timeout property, controlled via the web.config section like so:
<forms name="foo" loginUrl="~/Account/Login" timeout="30" />
This setting has existed since .NET 1.0, I believe, but only in .NET 4 did we get a corresponding property on the FormsAuthentication object. To access the Timeout property in .NET 4+, you just call
To do the same in .NET 3.5, you need to do this:
var defaultTimeout = TimeSpan.FromMinutes(30);
var xml = new XmlDocument();
var webConfigFilePath = Path.Combine(HttpRuntime.AppDomainAppPath, "web.config");
var node = xml.SelectSingleNode("/configuration/system.web/authentication/forms");
if (node == null || node.Attributes == null) return (defaultTimeout);
var attribute = node.Attributes["timeout"];
if (attribute == null) return (defaultTimeout);
if (Int32.TryParse(attribute.Value, out minutes)) return(TimeSpan.FromMinutes(minutes));
I'll file this under "Things that wrong with Forms Authentication, #217"
Friday, 17 January 2014
I’m going to France. I want to be able to use my phone for data when I’m out there, so I’m investigating the cheapest way to do this. My phone is on Orange, who are now owned by EE, so I wander over to http://explore.ee.co.uk/roaming/orange/france and have a look.
(I should mention here that I’m generally really happy with Orange. The reception’s good. Their network doesn’t randomly drop calls or send me text messages 12 hours late, and Orange Wednesdays are awesome.)
Anyway. Here’s their data options:
Before we even get into the chaos of daily limits and terms and conditions, notice how the EU 100MB daily bundle gives you 100MB for £3, whilst the EU Data 500MB bundle gives you 500Mb for a hundred and fifty pounds? Same data but the bundle offers “93% saving on standard rates” – which is such a huge discount as to be really quite unsettling. If someone tried to sell you a MacBook for £50, you’d be a bit suspicious, right?
|My Question||Website||T&Cs||Customer Services (referring to an internal T&C document dated Dec 15th 2013)|
|What happens if I go over 100MB in a single day?||“This bundle reoccurs up to 10 times until midnight of that same day (local time), each time the bundle reoccurs you will be charged an additional bundle fee and recieve additional bundle allowance. If you exceed the reoccuring bundle limit you’ll be charged 45.9p/MB.”” |
(Does this mean I get ten bundles per day? Or one bundle per day, for up to ten days?)
|“Any data used above the amount in your bundle, will be charged at our standard data roaming rate of 45.9p per MB. So, for example, if you have the £1 per day bundle and use more than your 20MB you will be charged an additional £1 for every additional 20MB you use up to 200MB (as the bundle reoccurs ten times). Any data usage in excess of 200MB will then be charged at our standard data roaming rate of 45.9p per MB.” |
(that sounds to me like you get ten bundles per day – otherwise it would just say “if you use more than 20Mb you’ll pay standard rates for the rest of the day” – no?)
|Customer services advised me that bundles only work once per day – so when you reach 100MB, you’ll pay normal roaming charges until midnight, and you’ll get another 100MB bundle the next day.|
|How many times can I use the bundle in a single day?||See above.||“A daily bundle will last until midnight (local time of the country you purchased the bundle in) on the day you made the purchase, or until you have used up your data allowance, whichever comes first in time. Once you’ve purchased a bundle, you will be opted in for the bundle to reoccur up to ten times” |
Doesn’t say if that’s ten times per day, or ten times per trip, or per billing period, or what.
|Just once – see above. You can’t use two daily bundles in the same day.|
|How many days does it last for?||Really unclear whether it’s ten bundles per day – for as many days as you like – or whether it’s one bundle per day, for up to ten days. And no indication of whether that ten day limit is per trip or per billing period or what.||See above.||Customer services said there’s no limit – if I went to France for fifty days, I’d get fifty bundles. One per day, for the duration of my trip.|
|How much does it cost once I exceed my bundle limit?||“If you exceed the reoccuring bundle limit you’ll be charged 45.9p/MB.”||“Any data used above the amount in your bundle, will be charged at our standard data roaming rate of |
45.9p per MB.”
|£3.70 per MB. Though I was advised that information might be out of date.|
|What does the “ten bundle” limit actually mean?||Unclear||Unclear||No idea. Neither of the advisors I spoke to could tell me what the “up to 10 times” limit actually meant.|
So, let’s spin those various answers into some possible phone bills, bearing in mind nobody can actually give me a definitive answer. Imagine we’re going to France from Feb 1st to Feb 16th, and we’re going to use 25Mb/day most days on e-mail and Facebook and the like, and 250Mb on Fridays, ‘cos we’re watching snowboarding videos on YouTube.
- With 1 EU100 bundle per day, unlimited days – that’d cost us £185.70
- At 1 EU100 bundle per day, up to 10 days – would cost us £270.98
- The EU500 plan? Given our 500MB quota runs out halfway through our trip, we’d pay £322.13
- If the chap on the phone was right about £3.70/MB, we’d be looking at £1,110 in excess data charges for our two nights of YouTube, and a total bill of £1,158.
And on top of all that, whoever wrote their (legally binding?) terms & conditions cannot spell ‘receive’ or ‘recurring’.
No wonder I have a headache.
UPDATE: So when I texted EU100 to 2088 to activate the bundle, it failed… I rang them (again), and apparently there’s already a bundle on there. It’s been on there since February 2013. Will it run out? “No, sir”. Is there any kind of limit on how many days I get? “No, sir.”
So that’s an hour of research and phone calls to work out that nobody knows for sure what the bundle is, but it’s probably safe to assume it *doesn’t* run out because I’ve already got one and it’s been active for nearly a year.