P.P.S. You know you can forward this to your friends, right?
About Scott
Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.
Running a site in the cloud and paying for CPU time with pennies and fractions of pennies is a fascinating way to profile your app. I mean, we all should be profiling our apps, right? Really paying attention to what the CPU does and how many database connections are main, what memory usage is like, but we don't. If that code doesn't affect your pocketbook directly, you're less likely to bother.
Interestingly, I find myself performing optimizations driving my hybrid car or dealing with my smartphone's limited data plan. When resources are truly scarce and (most importantly) money is on the line, one finds ways - both clever and obvious - to optimize and cut costs.
Sloppy Code in the Cloud Costs Money
I have a MSDN Subscription which includes quite a bit of free Azure Cloud time. Make sure you've turned this on if you have MSDN yourself. This subscription is under my personal account and I pay if it goes over (I don't get a free pass just because I work for the cloud group) so I want to pay as little as possible if I can.
One of the classic and obvious rules of scaling a system is "do less, and you can do more of it." When you apply this idea to the money you're paying to host your system in the cloud, you want to do as little as possible to stretch your dollar. You pay pennies for CPU time, pennies for bandwidth and pennies for database access - but it adds up. If you're opening database connection a loop, transferring more data than is necessary, you'll pay.
I recently worked with designer Jin Yang and redesigned this blog, made a new home page, and the Hanselminutes Podcast site. In the process we had the idea for a more personal archives page that makes the eponymous show less about me and visually more about the guests. I'm in the process of going through 360+ shows and getting pictures of the guests for each one.
I launched the site and I think it looks great. However, I noticed immediately that the Data Out was REALLY high compared to the old site. I host the MP3s elsewhere, but the images put out almost 500 megs in just hours after the new site was launched.
You can guess from the figure when I launched the new site.
I *rarely* have to pay for extra bandwidth, but this wasn't looking good. One of the nice things about Azure is that you can view your bill any day, not just at the end of the month. I could see that I was inching up on the outgoing bandwidth. At this rate, I was going to have to pay extra at the end of the month.
I thought about it, then realized, duh, I'm loading 360+ images every time someone hits the archives page. It's obvious, of course, in retrospect. But remember that I moved my site into the cloud for two reasons.
Save money
Scale quickly when I need to
I added caching for all the database calls, which was trivia, but thought about the images thing for a while. I could add paging, or I could make a "just in time" infinite scroll. I dislike paging in this instance as I think folks like to CTRL-F on a large page when the dataset isn't overwhelmingly large.
ASIDE: It's on my list to add "topic tagging" and client-side sorting and filtering for the shows on Hanselminutes. I think this will be a nice addition to the back catalog. I'm also looking at better ways to utilize the growing transcript library. Any thoughts on that?
Then, give the lazy load plugin a selector. You can say "just images in this div" or "just images with this class" however you like. I chose to do this:
The most important part is that the img element that you generate should include a TINY image for the src. That src= will always be loaded, no matter what, since that's what browsers do. Don't believe any lazy loading solution that says otherwise. I use the 1px gray image from the github repo. Also, if you can, set the final height and width of the image you're loading to ease layout.
<a href="/363/html5-javascript-chrome-and-the-web-platform-with-paul-irish" class="showCard"> <img data-original="/images/shows/363.jpg" class="lazy" src="/images/grey.gif" width="212" height="212" alt="HTML5, JavaScript, Chrome and the Web Platform with Paul Irish" /> <span class="shownumber">363</span> <div class="overlay">HTML5, JavaScript, Chrome and the Web Platform with Paul Irish</div> </a>
The image you're going to ultimately load is in the data-original attribute. It will be loaded when the area when the image is supposed to be enters the current viewport. You can set the threshold and cause the images to load a littler earlier if you prefer, like perhaps 200 pixels before it's visible.
$("img.lazy").lazyload({ threshold : 200 });
After I added this change, I let it run for a day and it chilled out my server completely. There isn't that intense burst of 300+ requests for images and bandwidth is way down.
10 Websites in 1 VM vs 10 Websites in Shared Mode
I'm running 10 websites on Azure, currently. One of the things that isn't obvious (unless you read) in the pricing calculator is that when you switch to a Reserved Instances on one of your Azure Websites, all of your other shared sites within that datacenter will jump into that reserved VM. You can actually run up to 100 (!) websites in that VM instance and this ends up saving you money.
Aside: It's nice also that these websites are 'in' that one VM, but I don't need to manage or ever think about that VM. Azure Websites sits on top of the VM and it's automatically updated and managed for me. I deploy to some of these websites with Git, some with Web Deploy, and some I update via FTP. I can also scale the VM dynamically and all the Websites get the benefit.
Think about it this way, running 1 Small VM on Azure with up to 100 websites (again, I have 10 today)...
...is cheaper than running those same 10 websites in Shared Mode.
This pricing is as of March 30, 2013 for those of you in the future.
The point here being, you can squeeze a LOT out of a small VM, and I plan to keep squeezing, caching, and optimizing as much as I can so I can pay as little as possible in the Cloud. If I can get this VM to do less, then I will be able to run more sites on it and save money.
The result of all this is that I'm starting to code differently now that I can see the pennies add up based on a specific changes.
About Scott
Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.
I've been spending the evenings and weekends lately redesigning the blog and the Hanselminutes podcast site. I hadn't realized how cheesy looking the podcast site was all these years. I'd like to get the show expanded to a wider audience as I feel that listenership has kind of flattened lately. I am in the process of adding faces for ALL 360+ shows going back 6 years.
I also wanted a nicer in-browser audio experience so I assumed I'd just drop in the audio tag and be done, right?
The HTML5 Audio tag is wonderful, right? Just works. This is the dream:
<audio id="audioplayer" preload="metadata" type="audio/mp3" > <source src="http://s3.amazonaws.com/hanselminutes/hanselminutes_0363.mp3" type="audio/mp3"/> Your browser doesn't support the HTML audio tag. Be sad. </audio>
Ya, Firefox currently doesn't support MP3 audio so it just flashes once then disappears. Firefox will support MP3s in audio soon though by using the underlying operating system to play the stream rather than its own embedded code.
In Firefox 20 (the beta channel) on Windows 7 and above, you can test MP3 Audio support by turning on the preference media.windows-media-foundation.enabled in about:config.
The part I was disappointed in was more of an HTML5 specification issue. Notice that while I have fallback text present, I don't see it in Firefox. That's because fallback elements are only used if your browser doesn't support the audio tag at all.
It doesn't do what I would expect at all. What I want is "Can you support any of these audio sources? No? Fallback." This seems intuitive to me.
I talked to Chris Double via Christian Heilmann at Mozilla and he said "You'd need to raise the issue with WHATWG/W3C. It's been debated before in the past. " Indeed it has. From Oct 2009, more people saying that it's not intuitive to fall back in this way:
I expected (incorrectly, in this case) that if I only produced one source element (an MP4), Firefox would drop down to use the fallback content, as it does if I include an object element for a format not supported (for example, if I include a QuickTime object and QT is not installed, the user sees fallback content). As far as I can see, the only option in this situation is to rely on Javascript and the video element's canPlayType() function. - Kit Grose
This lack of an intuitive fallback means that I can't make an audio player that works everywhere using just HTML. I have to use JavaScript, which is a bummer for such a fundamental scenario.
Getting HTML5 audio to fall back correctly in all browsers
Instead you have to make an audio tag dynamically, then interrogate the tag. This applies to both audio and video tags. I ended up using some code from my friend Matt Coneybeare.
The AudioPlayer.embed at the end there is the WordPress AudioPlayer in standalone form. This way on Firefox I get the flash player since it answered false to canPlayType.
A Responsive and Touch-Friendly Audio Player in HTML5
However, the default audio player made by the <audio> tag is kind of lame, and I'd like it to better support touch, look great on tablets, etc. For this, I'll turn to Osvaldas Valutis's AudioPlayer. It's a nice little jQuery plugin that replaces the <audio> element with a lovely chunk of HTML. Since you can't actually style the HTML5 <audio> element, people just hide it, recreate it, then broker calls over to the hidden-but-still-working audio element.
This plugin, along with a little CSS styling of its default colors gives me a nice audio player that looks the same and works everywhere. Except Firefox 19/20 until the next version Firefox answers true to "canPlayType" and then it should just start working! Until then, it's the Flash fallback player, which works nicely as well.
The other problem is the QuickTime plugin that most Firefox users have installed. When styling with the Osvaldas' AudioPlayer, the JavaScript interrogation would cause Firefox will prompt folks to install it in some cases if it's not there, and it still doesn't work if it is installed.
I ended up modifying Matt's detection a little to work with this Osvaldas' styling. I realize the code could be more dynamic with less elements, but this was easier for me to read.
First, try the audio tag. Works? Great, style it with audioPlayer();
Can't do MP3 audio? Dynamically make a Flash player with that P. Hide the audio player (likely not needed.)
Unfortunately for readability, there's the ".audioPlayer" jQuery plugin that styles the HTML and there's the "AudioPlayer" flash embed. They are different but named the same. I didn't change them. ;)
<audio id="audioplayer" preload="auto" controls style="width:100%;" > <source src="your.mp3" type="audio/mp3"> Your browser doesn't support the HTML audio tag. You can still download the show, though! </audio> <p id="audioplayer_1"></p> <script type="text/javascript"> var audioTag = document.createElement('audio'); /* Do we not support MP3 audio? If not, dynamically made a Flash SWF player. */ if (!(!!(audioTag.canPlayType) && ("no" != audioTag.canPlayType("audio/mpeg")) && ("" != audioTag.canPlayType("audio/mpeg")))) { AudioPlayer.embed("audioplayer_1", {soundFile: "your.mp3", transparentpagebg: "yes"}); $( '#audioplayer').hide(); } else /* Ok, we do support MP3 audio, style the audio tag into a touch-friendly player */ { /* If we didn't do the "if mp3 supported" check above, this call would prompt Firefox install quicktime! */ $( '#audioplayer' ).audioPlayer(); } </script>
All in all, it works pretty well so far.
ODD BUG: Chrome does seem to have some kind of hang where this audio player is getting blocked while the comments load on my site. Any JavaScript experts want to weight in? If you load a page - like this one - and hit play before the page is loaded, the audio doesn't play. This only happens in Chrome. Thoughts?
While you're here, check out the new http://hanselminutes.com and consider subscribing! It's "Fresh Air for Developers."
About Scott
Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.
My blog and all the sites in and around it are a mix of .NET 2.0, 3.5 and 4. This blog engine is currently .NET 3.5 and runs at http://hanselman.com/blog, but the application at http://hanselman.com/ (the root) is .NET 4.
You can happily mix and match applications across .NET versions on a single IIS instance. You can see how mixed my system is in the screenshot at right there.
However, things got messy when I changed the parent / application to .NET 4, but kept the child /blog as .NET 3.5 (the 2.0 CLR). I got lots of errors like
Unrecognized attribute ‘targetFramework’. Note that attribute names are case-sensitive. The targetFramework attribute was inherited from the root .NET 4 Web.config file in the Default Web Site root using ASP.NET configuration inheritance and confused the /blog .NET 2 application.
I didn't want to change the /blog applications' web.config. I just wanted to stop it from inheriting the settings from the parent application. Turns out you can wrap whole sections in a location tag, and then tell that scoped tag to prevent child applications from inheriting.
What you do is change the parent .NET 4 app's web.config to indicate its settings shouldn't flow down to the children, like the .NET 2/3.5 /blog app.
I chose to change this settings for all of System.Web, but you could do it on a per-section basis if you preferred.
Hope this helps you!
About Scott
Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.
When you've got an idea for an app, it's likely that you've got the idea for that app in more than one place. By this I mean, you'll start with a phone app, then make a desktop app, then a web app. Or you'll make a game on one platform and then want it to work anywhere. In fact, with the rise of Xamarin, C# lets you put an app in every AppStore in the world with one language.
You likely already knew that you can target different versions of the .NET framework. You likely also know that there are small .NET Frameworks like Silverlight and the tiny .NET Micro Framework.
The idea is that you write a library that contains as much shared functionality as possible and then every application uses your now "portable" library. However, the subset of classes that are available are a subset. That means you can only use things that are available in the intersection of the targets you choose. Check this dialog:
However, most folks that use Portable Libraries have ended up using them mostly for ViewModels - just simple classes without any real functionality. Almost as if we had a DLL full of structs. There are some great posts on how to make Portable Class Libraries work for you using architectural techniques like indirection and appropriate interfaces.
The number one complaint around code resuse and the number one voted item over at the Visual Studio UserVoice was "Add HttpClient support in Portable Class Libraries (including Windows Phone 8)." Why? Because the GETting of a remote resource via HTTP is such a fundamental thing that it'd be awesome to be able to bake that data access into a portable library and use it everywhere.
Now there is a Portable Http Client and you can get it via NuGet!
Here's an example of what the code looks like for a GET. Note that I'm using async and await also.
public static async Task<HttpResponseMessage> GetTheGoodStuff() { var httpClient = new HttpClient(); HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, "http://hanselman.com/blog/"); var response = await httpClient.SendAsync(request); return response; }
If you were going to make a Twitter client (lame example, but bear with me) you could now put the JSON HTTP data access code in one library and share it across Windows Phone, Windows Store, WinForms, Console, whatever.
This is because .Net 4.0 and Windows Phone 7.5 did not support the async/await keywords. In order to fix this add a reference to the Microsoft.Bcl.Async nuget package, which adds the support for async and await in .NET 4 and WP7.5. Here's a post with more details on how this backport works.
Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.
