Categories
.net code development

Thoughts on Global Azure Bootcamp 2019

I’ve got a collaborative post coming up on the talks themselves on my employer’s blog but as a speaker and tech enthusiast, I wanted to share a few thoughts on the bootcamp as a whole.

Firstly, I’d like to thank Gregor Suttie who organised the Glasgow chapter under the Glasgow Azure User Group banner.

It’s an impressive feat getting so many speakers on so many topics around the world. Each city is going to be limited in the talks they can offer, but I was impressed by the distances some of the speakers at the Glasgow event traveled.

I would have liked to have been more of a global feel. I know the challenges of live video, especially interactive, but this is an event that would benefit from some of that (or indeed, more speakers participating the the online bootcamp via pre-recorded YouTube videos). I realize an event like Google I/O or Microsoft Build is different in focus, being company rather than community driven, but it felt like a set of parallel events rather than one, so it also feels as if some of the content is going to be lost, and there were a lot of interesting looking talks in other cities that turned up on the Twitter hashtags.

There’s obviously a lot to cover under the Azure umbrella, so it’s going to be hard to find talks that interest all the audience all the time, and it was hard to know where to pitch the content. I aimed for an overview for beginners which I think was the right CosmosDb pitch for the Glasgow audience, but I was helped by the serendipity of coming after an event sourcing talk so I could stand on the shoulders of that talk for some of my content.

I would maybe have liked to see more “virtual tracks” so that it was easier to track themes within the hashtags, whether it’s general themes like “data” or “serverless” or technology/tool focused like “CosmosDB”, “Azure DevOps” or “Office 365”, to help me connect with the other channels and see what content is must interesting to follow up. Although Twitter was a good basis for it, I think there’s scope to build a conversational overview on top, into which YouTube videos, Twitter content, Github links, blog posts, official documentation and slide content could be fed.

As a speaker, the biggest challenge was keeping my knowledge up to date with all the updates that are happening, and events like this do help, but as I’ve been on a project that’s Docker and SQL focused recently, it’s a lot of work on top of my day job to keep in touch with the latest updates to CosmosDb, especially as a few tickets on the project were picked up and moved to “In Progress” between submitting and delivering my talk, and a new C# SDK was released.

Categories
.net code data development

CosmosDb in The Real World : Azure Global Bootcamp 2019 (Glasgow)

Thank you to those who came to my talk today about CosmosDb. I hope you found it useful.

If you’d like to review the slides, you’ll find the presentation online here :

CosmosDb In The Real World – GitPitch

If you have any further questions please ask below and I’ll do my best to answer.

Categories
.net code

Self-testing configuration – the example.config story

Some halloween cakes reflected in a mirror
Mirror image

We’re all good developers and never store production secrets in our source code. We have to keep them somewhere though.

If you’re an ASP.Net developer and you store your secrets in a separate file, how do you check them on release?

In a previous job, we were building an application in AWS EC2, which meant we couldn’t sit on top of the lovely Azure Key Vault/secrets.json workflow, and instead used a secure file drop as part of the deployment. We had a couple of releases that failed because secrets that were available locally weren’t included in the release package, causing the website to fail to start. We didn’t have the nice logging provided by the .Net core configuration objects, so what we did was create configuration documentation in the form on an example.config file that contained all the keys we expected, and populated dummy values. On startup, we’d compare the list of keys in the example.config which did not contain any secrets, with the actual config, and fail the startup with a report of which keys were different so we had a very quick way of checking the config was in sync with expectations.

Categories
.net development

Debugging Asp.Net Core 2 apps in Azure

I’ve been getting under the skin of Asp.Net Core 2 following a failed experiment with Asp.Net Core v1. I certainly found .Net standard and the associated framework support to be very welcome, and unlike my previous project we didn’t need to support GDI or SignalR libraries, so it’s much more in the Core sweet spot.

I’ll talk about the project and the technologies involved in some follow up posts, so if you’ve got any real-world questions on Asp.Net core, React/Redux with Typescript, or CosmosDb in C#. let me know and I’ll try and address them as I get to those technologies.

For now, though, I want to start with the basics. Asp.Net core on Azure works great, mostly, but if something goes wrong in Startup.cs, there’s no Application Insights, a generic 502.5 IIS error – which just means it can’t talk to Kestrel, and no web logs to help you. So before you deploy to Azure, do yourself a favour and add the following to web.config so you’ve got logs to help you.

<system.webServer>
<handlers>
<add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />
</handlers>
<aspNetCore processPath="dotnet" arguments=".\web.api.dll" stdoutLogEnabled="true" stdoutLogFile=".\logs\stdout" forwardWindowsAuthToken="true" />
</system.webServer>

That way, if you do see a 502.5 error on your site, you can jump into Kudu and start reading the logs. They can grow quite quickly, depending on your web app lifecycle settings, so you may benefit from a regular cleanout of your logs folder.

If the logs still aren’t helping, or you don’t understand what you’re seeing, there’s a nice Asp.Net core 2 troubleshooting guide over at MSDN, but not all of it applies to Azure.

Categories
.net development programming

My .net journey

With the release of Visual Studio 2017 and .net core, I’ve seen a few folk talking about their story with the platform. This is mine.

I’ve never been the biggest Microsoft fan, ever since I grabbed a copy of Mandrake Linux and figured out how much more tinkering was available and how much more logical certain operations were than on Windows 95. But it was definitely still a tinkerers platform.

But I got an internship at Edinburgh University whilst I was a student there, funded by Microsoft. I got a laptop for the summer and a iPaq (remember that?) to keep. I also got a trip to Amsterdam to meet the other interns and some folk from Microsoft, back before they had much more than sales people in the UK. And they told me, no matter how much anyone hates Microsoft, they always hate Oracle more.

It meant that I was among the first to get the .net 1.0 CD, so I could legitimately claim later that yes, I did have 2 years of .net experience.

But from there, I stayed in Linux, learning the joys of Java Threading on Solaris (top tip : Sun really should have known what they were doing, that they didn’t means I can see some of why they failed – it was far easier working with threads on Red Hat or Windows).

And then I did my PhD, digging into device drivers, DirectX and MFC. I hated Microsoft’s Win32 GUI stuff, but the rest, in C++, was quite nice. I enjoyed being closer to the metal, and shedding the Java ceremony. I trained on templates and started to understand their power. And Java just wasn’t good enough.

I wrote research projects in C++ and data analysis engines in Python. It was good.

But Java came back, and I wrote some media playback for MacOS, and fought iTunes to listen to music. And I vowed never to buy from Apple because both were a right pain.

And I needed a new job. And I’d written bots in IronPython against C#, so I got a .Net job. And I missed the Java and Python communities, the open source chatter. And I wanted to write code in C# that was as beautiful and testable as C++. And I wanted to feel that Bulmer’s Developers! chant was a rallying call, not a lunch order from a corporate monster.

So I found alt.net and it was in Scotland, and I wrote a lot of code, and I learned that open source did exist in c#, and that there was a conference named after that chant and I met more like minded developers. I fought my nervousness and my stumbling voice and I found some confidence to present. And blog. And help write a package manager. And then everyone else learned Ruby.

And then the Scotts joined Microsoft and alt.net became .net. And then LINQ came and I remembered how clean functional programming is, and I started feeling like I was writing Python if I squinted hard, and ignored types. And then core came, and Microsoft had some growing pains. But it’s a sign that the company has completely shifted in the right direction, learning from the guys who left for Ruby. And Node.

I’m proud of what I’ve built in C#, and it’s a much better language than Java, now. It’s definitely the right choice for what I’ve built. The documentation is definitely better than Apple or Sun/Oracle produce, although MSDN and docs.microsoft.com are having some migration pains of its own.

And alt.net is making a comeback.

And I still use Python on hobby projects.

Categories
.net development programming

Windows resource limit in services

Here’s a little something that stumped us for a few days and might be worth posting to save others time.

Following a move to IIS8.5, we started seeing “Out of resource” errors on a server that did not appear to be bottlenecked by disk, CPU or RAM.

It turns out that since a previous version of IIS, the Application Pool service doesn’t grab GDI handles as it runs as a non-interactive service, so anything relying on that, such as a DLL with GDI dependencies, like an image resizing library, only gets the non-interactive desktop heap for graphical services. As soon as you get enough calls into that DLL, the heap fills and the program crashes with the “Out of resources” error.

So you recreate the issue in the debugger, attached to IIS Express, running in user space, with the full interactive desktop heap, and you can’t recreate the issue.

To fix the problem, you need to carefully adjust the heap limit in one of the ugliest registry values in Windows. Have a read here to find out what the Desktop Heap is and the registry key that controls it, then up the 3rd SharedSection value (the non-interactive heap) in small increments (lest you put in a value too high, break the interactive heap and lose the ability to log on).

And then find a way to rewrite the DLL.

Categories
.net code development

Naming things is hard – Microsoft’s Core problem

There are 2 hard problems in computer science: cache invalidation, naming things, and off-by-1 errors.

Microsoft are changing the name of the next iteration of .Net – what was .Net 5.0 is now .Net Core 1.0, and like Rick Strahl, I like the idea, but I’m not find of the timing. Although, as it’s pre-release, anyone writing production code on it was playing with fire anyway. I’m not a big fan of the naming scheme though.

The timing issue is an easy one to solve. I’ve had projects running under placeholder codewords for months whilst the business agreed a proper name. Microsoft has been doing this for years. No-one expected to see Windows Chicago, Windows Threshold or SQL Server Denali. No-one would have expected to ship .Net Sapphire (hey, they’ve admitted that were going after the Ruby developers 😉 ) Everyone knew they were codewords, to be replaced pre-release once marketing figured out what year it was being released – or the regression testers discovered how much old code thought 9 < 7.

The problem I have with it is that ASP.Net Core sounds like part of the family that includes ASP.Net MVC, ASP.Net SignalR or ASP.Net AJAX, whereas it actually replaces the ASP.Net part with its own .Net Core stack. I can’t at the moment think of a better way to name the ASP.Net Core though, without losing the ASP.Net brand.

The naming works when you compare .Net Framework to .Net Core, and to me it’s as natural as when Netscape open sourced Navigator to give us Firefox (once they managed to choose a unique name). It was from some of the same team, and it did the same job, but the new one was leaner, faster and more focused.

Naming things is hard, but starting a new roadmap and resetting expectations is definitely the right thing to do. .Net and the ASP.Net frameworks have needed a decent overhaul for a while to fix the untestable, interdependent ball of mud that the .Net framework install had become. I like the new Core world, with NuGet and Gulp and Grunt, and Github at the heart of development. This is not a Microsoft I thought I’d see when I was at the ScotAlt.Net meetings all those years ago.

Alt.Net is dead. Long live .Net Core.