Category Archives: development

Should you go to Microsoft Build?

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In the beginning there was the Professional Developers Conference (PDC) – the first was in 1992. They were fantastic events, with deep dives into the innards of Windows and how to develop applications on Microsoft’s platform. Much of the technology presented was in early preview and often did not work quite right; some things that were presented never made it to production, famous examples including “Hailstorm” also known as .NET My Services, and the WinFS file system originally slated for Windows Vista.

These events seemed to be a critical part of Microsoft’s development cycle. Internally teams would ready their latest stuff for a PDC session, which was then adapted and re-presented at other events around the world.

Then PDC kind-of morphed into Microsoft Build, the first of which took place in September 2011. Unlike PDC, Build was specifically focused on Windows, and was originally associated with Windows 8 and its new app platform, WinRT. Part of the vision behind Windows 8 was that it would have a strong app ecosystem and Build was about enthusing and informing developers about the possibilities.

As it turned out, the Windows 8 app ecosystem was a bit of a disaster for various reasons. Microsoft had another go with UWP (Universal Windows Platform) in Windows 10. Build in April 2015 was an amazing event, where the company appeared to be going all-out to make UWP on both desktop and mobile a success. Not only was the platform itself being enhanced, but we also got Project Centennial (deliver desktop applications via the Store), Project Astoria (compile Android apps to UWP) and Project Islandwood (compile iOS code for UWP).

Just a few months later the company made a huge about-turn. CEO Satya Nadella’s Aligning Engineering to Strategy memo signalled the beginning of the end for Windows Phone, and the departure of Stephen Elop and the dismantling of the Nokia devices acquisition. That was the end of the universal part of UWP.

Project Astoria was scrapped. The Windows Bridge for iOS (Project Islandwood) still just about exists, but its core rationale (get iOS apps to Windows Phone) is now irrelevant.

Nadella steered the company instead towards “the intelligent cloud” and to date that strategy has been successful, with impressive growth for Office 365 and Microsoft Azure.

Microsoft has announced Build 2018, in early May, I find it intriguing, given the history of Build, that Windows is not currently mentioned on the event’s home page. In the page description metadata it says:

Microsoft Build 2018, Seattle, WA May 7-9, 2018. Microsoft’s ultimate developer conference focused on cloud, artificial intelligence, mixed reality, and more.

In the main text of the page, about the only specific topics mentioned are these:

Take in keynotes by Microsoft CEO Satya Nadella and other visionaries behind the Intelligent Cloud and Intelligent Edge

That sounds like a focus on Azure and AI/ML/IoT/Big Data cloud services, and on mobile and IoT devices. It is a long way removed from the original concept of Build as all about Windows and its application platform.

Windows remains important to Microsoft, and to all of us who use it day to day. Still, if you think about cutting-edge software development today, Windows desktop applications are probably not the first thing to come to mind, nor UWP for that matter.

This being the case, it does make sense for the company to focus on its cloud services at Build, and on diverse mobile platforms through what is now an amazing range of cross-platform tools in Visual Studio.

Of course there will in fact also be Windows stuff at Build, including Windows and HoloLens Mixed Reality, Cortana skills and UWP improvements.

Still, if you can only get to one big Microsoft event in the year, Ignite in September is now a bigger deal and closer to the heart of the new (or current) Microsoft.

Let me add that these Microsoft events, whether Build or PDC, have on occasion seen some stunning announcements. Examples include the unveiling of C# and the .NET Framework, the 2003 Longhorn reveal (yes it all turned to dust), Windows 7 in 2008, and Windows 8 in 2011.

I would like to think that the company still has the capacity to surprise and amaze us; but it must be admitted that the current Build pitch is rather unexciting. Google I/O, incidentally, is on at the same time.

Microsoft introduces new feedback system for technical documentation, will delete existing comments

Microsoft is introducing a new feedback system for https://docs.microsoft.com, used for its technical documentation.

The new system, which you can already see for certain topics such as the Visual Studio IDE, is based on GitHub issues. When you leave a comment, you can specify whether it concerns documentation or product functionality.

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So far so good, but the downside is that all existing comments will be deleted:

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The statement “Old comments will not be carried over. If content within a comment thread is important to you, please save a copy.” is unhelpful. Nobody knows what comments will be useful to them in future.

Few things sap enthusiasm for community participation more than having all the past contributions into which you have put effort suddenly zapped. Nor is this the first time, as user guibirow notes:

As much I like the new system idea, I hate the fact that this is happening over and over.
It used to be a Disqus comment system, then moved to LiveFyre, then moved now to this new system, what will be the next?
The worst part of this all is that MS does not care about past content lost on these discussions, so many times I found issues described in the docs that are gone now.
Please, pay attention to your previous mistakes, don’t let the information be lost again, at lest import them as closed issue in the new system.

Sometimes progress has a cost and that is understood. However it is not impossible to migrate content from one system to another. It just takes effort.

Update: Microsoft’s Rob Eisenberg has responded with an explanation and mitigation plan regarding existing comments. He says that a straight migration of the comments is impossible:

    • There is a lot of garbage, spam and even dangerous content within existing LiveFyre comments which would violate GitHub terms of usage and our open source code of conduct, as well as cause security problems.
    • There isn’t a good way to map LiveFyre users to GitHub users and using a bot account to anonymously add comments is questionable with respect to OSS practices and GitHub terms of use.
    • For legal and privacy reasons, we cannot move user-associated data from one system to another without consent from users (GDPR).
    • LiveFyre conversations are threaded, while GitHub issues are not.
    • Placing the old comments into the GitHub Issues system would derail the entire GitHub Issues workflow for both customers and employees and muddle the data.
    • It isn’t clear whether there is a way to invoke GitHub APIs for a migration of this scale such that it wouldn’t violate GitHub API terms of use.

He also has an archiving proposal:

We would take the comments from an article on docs.microsoft.com and then convert them into a Markdown file. During this process, we would strip all user info (remember GDPR). The Markdown file would then be committed to a GitHub repo. Finally, at the bottom of the feedback section, next to the link that says "View on GitHub" we would add a second link that said something like "View Comment Archive". This link would connect you directly to the Markdown comment file for that page.

This sounds positive. At the same time, it is a mess that illustrates some of the disadvantages of a “best of breed” approach to solving technical problems. If Microsoft could use its own technology to host a documentation and commenting system, and a source code management and issue tracking system for that matter, this issue would not occur, and users would not need multiple accounts, causing the legal issues mentioned above.

Microsoft in fact used to use its own platform for all the above but decided to shift to using third-party solutions because they worked better. That seemed to be a good thing, improving user experience and productivity, but becomes a problem when what seems to be the best third-party option changes.

What the Blazor! After Silverlight, .NET in the browser reappears by another route

Silverlight, Microsoft’s browser plug-in which included a cut-down .NET runtime, once seemed full of promise for developers looking for an end-to-end .NET solution, cross-platform on Windows and Mac, and with support for “out of browser” applications for a native-like experience.

Silverlight was killed by various factors, including the industry’s rejection of old-style browser plug-ins, and warring factions at Microsoft which resulted in Silverlight on Windows Phone, but not on Windows 8. The Windows 8 model won, with what became the Universal Windows Platform (UWP) in Windows 10, but this is quite a different thing with no cross-platform support. Or there is Xamarin which is cross-platform .NET, and one day perhaps Microsoft will figure out what to do about having both UWP and Xamarin.

Yesterday though Microsoft announced (though it was already known to those paying attention) Blazor, an experimental project for hosting the .NET Runtime in the browser via WebAssembly. The name derives from “Browser + Razor”, Razor being the syntax used by ASP.NET to combine HTML and C# in a web application. C# in Razor executes on the server, whereas in Blazor it executes on the client.

Blazor is enabled by work the Xamarin team has done to compile the Mono runtime to WebAssembly. Although this sounds like a relatively large download, the team is hoping that a combination of smart linking (to strip out unnecessary code in both applications and the runtime) with caching and HTTP compression will make this acceptable.

This post by Steve Sanderson is a good technical overview. Some key points:

– you can run applications either as interpreted .NET IL (intermediate language) or pre-compiled

– Blazor is an SPA (Single Page Application) framework with solutions for routing, state management, dependency injection, unit testing and more

– UI components use HTML and CSS

– There will be a browser API which you can call from C# code

– you will be able to interop with JavaScript libraries

– Microsoft will provide ASP.NET libraries that integrate with Blazor, but you can use Blazor with any server-side technology

What version of .NET will be supported? This is where it gets messy. Sanderson says Blazor will support .NET Standard 2.0 or higher, but not completely in the some functions will throw a PlatformNotSupported exception. The reason is that not all functions make sense in the context of a Blazor application.

Blazor sounds promising, if developers can get past the though the demo application on Azure currently gives me a 403 error. So there is this video from NDC Oslo instead.

The other question is whether Blazor has a future or will join Silverlight and other failed attempts to create a new application platform that works. Microsoft demands much patience from its .NET community.

C# and .NET: good news and bad as Python rises

Two pieces of .NET news recently:

Microsoft has published a .NET Core 2.1 roadmap and says:

We intend to start shipping .NET Core 2.1 previews on a monthly basis starting this month, leading to a final release in the first half of 2018.

.NET Core is the cross-platform, open source implementation of the .NET Framework. It provides a future for C# and .NET even if Windows declines.

Then again, StackOverflow has just published a report on the most sought-after programming languages in the UK and Ireland, based on the tags on job advertisements on its site. C# has declined to fourth place, now below Python, and half the demand for JavaScript:

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To be fair, this is more about increased demand for Python, probably driven by interest in AI, rather than decline in C#. If you look at traffic on the StackOverflow site C# is steady, but Python is growing fast:

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The point that interest me though is the extent to which Microsoft can establish .NET Core beyond the Microsoft-platform community. Personally I like C# and would like to see it have a strong future.

There is plenty of goodness in .NET Core. Performance seems to be better in many cases, and cross-platforms is a big advantage.

That said, there is plenty of confusion too. Microsoft has three major implementations of .NET: the .NET Framework for Windows, Xamarin/Mono for cross-platform, and .NET Core for, umm, cross-platform. If you want cross-platform ASP.NET you will use .NET Core. If you want cross-platform Windows/iOS/macOS/Android, then it’s Xamarin/Mono.

The official line is that by targeting a specification (a version of .NET Standard), you can get cross-platform irrespective of the implementation. It’s still rather opaque:

The specification is not singular, but an incrementally growing and linearly versioned set of APIs. The first version of the standard establishes a baseline set of APIs. Subsequent versions add APIs and inherit APIs defined by previous versions. There is no established provision for removing APIs from the standard.

.NET Standard is not specific to any one .NET implementation, nor does it match the versioning scheme of any of those runtimes.

APIs added to any of the implementations (such as, .NET Framework, .NET Core and Mono) can be considered as candidates to add to the specification, particularly if they are thought to be fundamental in nature.

Microsoft also says that plenty of code is shared between the various implementations. True, but it still strikes me that having both Xamarin/Mono and .NET Core is one cross-platform implementation too many.

Generating code for simple SQL Server data access without Entity Framework, works with .NET Core

I realise that Microsoft’s Entity Framework is the most common approach for data access in the .NET world, but I have also always had good results from a simple manual approach using DbConnection, DbCommand and DataReader objects, and like the fact that I can see and control exactly what SQL gets executed. If you prefer using Entity Framework or another abstraction that is fine and please stop reading now!

One snag with this more manual approach is that you have to write tedious code building SQL statements. I figured that someone must have written a utility application to generate this code but could not find one quickly so I did my own. It supports both C# and Visual Basic. The utility connects to a database and lets you generate a class for each table along with code for retrieving and saving these objects, ready for modification. Here you can see a generated class:

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and here is an example of the generated data access code:

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This is NOT complete code (otherwise I would be perilously close to writing my own ORM) but simply automates creating SQL parameters and SQL statements.

One of my thoughts was that this code should work well with .NET core. The SQLClient implements the required classes. Here is my code for retrieving an author object, mostly generated by my utility:

public static ClsAuthor GetAuthor(string authorID)
        {
            SqlConnection conn = new SqlConnection(ConnectString);
            SqlCommand cmd = new SqlCommand();
            SqlDataReader dr;
            ClsAuthor TheAuthor = new ClsAuthor();
            try
            {
                cmd.CommandText = "Select * from Authors where au_id = @auid";
                cmd.Parameters.Add("@auid", SqlDbType.Char);
                cmd.Parameters[0].Value = authorID;
                cmd.Connection = conn;
                cmd.Connection.Open();

                dr = cmd.ExecuteReader();

            if (dr.Read()) {

                    //Get Function
                    TheAuthor.Auid = GetSafeDbString(dr, "au_id");
                    TheAuthor.Aulname = GetSafeDbString(dr, "au_lname");
                    TheAuthor.Aufname = GetSafeDbString(dr, "au_fname");
                    TheAuthor.Phone = GetSafeDbString(dr, "phone");
                    TheAuthor.Address = GetSafeDbString(dr, "address");
                    TheAuthor.City = GetSafeDbString(dr, "city");
                    TheAuthor.State = GetSafeDbString(dr, "state");
                    TheAuthor.Zip = GetSafeDbString(dr, "zip");
                    TheAuthor.Contract = GetSafeDbBool(dr, "contract");
                }
            }
            finally
            {
                conn.Close();
                conn.Dispose();
            }

            return TheAuthor;
        }

Everything worked perfectly and I soon had a table showing the authors, using ASP.NET MVC.

In order to verify that it really does work with .NET Core I moved the project to Visual Studio Mac and ran it there:

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I may be unusual; but I am reassured that I have a relatively painless way to write a database application for .NET Core without using Entity Framework.

QCon London 2017: IoT insecurity, serverless computing, predicting technical debt, and why .NET Core depends on a 36,000 line C++ file

I’m at the QCon event in London, a multi-vendor conference aimed primarily at enterprise developers and architects.

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Adam Tornhill speaks at QCon London 2017

A few notes on day one. Alasdair Allan gave a keynote on security and the internet of things; it was an entertaining and disturbing résumé of all that is wrong with the mad rush to connect everything to the internet though short on answers; our culture has to change so that organisations such as hotels, toy manufacturers, appliance vendors and even makers of medical equipment take security seriously but it is not clear how this will come about unless so many bad things happen that customers start to insist on it.

Michael Feathers spoke on strategic code deletion, part of a track on “Dark code: the legacy/tech debt dilemma.” This was an excellent session; code is added to projects more often than it is removed, and lack of hygiene in this regard has risks including security, reliability and performance. But discovering which code is safe to remove is not always trivial, and Feathers explored some of the nuances and suggested some techniques.

Steve Faulkner gave a session on serverless JavaScript, or more specifically, using Amazon Web Services (AWS) Lambda and API Gateway. Faulkner said that the API Gateway was the piece that made Lambda viable for them; he is Director of Platform Engineering at Bustle, a busy content site based in the USA. In a nutshell, moving from EC2 VMs to Lambda has yielded both financial savings and easier management. The only downside is performance; each call to a Lambda function takes a minimum of 100ms whereas the same function on a WM might take 20ms. In the end it is not critical as performance remains satisfactory.

Faulkner said that AWS is ahead of its competitors (Microsoft, Google and IBM were mentioned) but when pressed said that both Microsoft and Google offered strong alternatives. Microsoft’s Azure Functions are spoilt by the need to specify a maximum scale, rather than scaling automatically, but its routing solution is in some ways ahead of AWS, he said. Google’s Functions will be great when out of beta.

Adam Tornhill spoke on A Crystal Ball to prioritise Technical Debt, another session in the dark code track. This was my favourite of the day. Tornhill presented a relatively simple way to discover what code you should refactor now in order to avoid future issues. His method is based on looking for files with many lines of code (a way of measuring complexity) and many commits (suggesting high importance and activity), the “hotspots” in your projects. For more detail and some utilities see Tornhill’s blog.

Why do we end up with bad or risky code in our software? Tornhill said that developers often mistake organisational problems for technical problems and try unsuccessfully to fix them with tools.

He also mentioned an example of high-risk code, the file gc.cpp which performs garbage collection in .NET Core, the next generation of Microsoft’s .NET Framework. This file is over 36,000 lines and should be refactored. There is a discussion on the subject here. It exactly bears out Tornhill’s point. A developer proposes to refactor the file, back in March 2015. Microsoft’s Karel Zikmund defends the status quo:

Why it is this way? … Partly historical reasons (it is this way since the start). Partly because devs working on it didn’t feel the urge to refactor it. Partly because splitting of gc.cpp is non-trivial and risky and because it does not bring too big value (ramp up in the code base can be gained also in the combination of reading BOTR and debugging the code). Why it is staying this way? … Cost/benefit/risk ratio is IMO not in favor of a change here.

Few additional thoughts:
Am I happy that there is only 1 large file? No, but it doesn’t hurt me much either.
Do I see the disadvantages of large file? Yes, but I don’t think they are huge. More like minor annoyances with easy workarounds.
And to turn it around: Do you see the risk of any changes here? Do you see the cost of extra careful code reviews to mitigate the risk?

Strictly technically, we truly believe this is a formatting change. If it was simple to split it up and if it would be low risk and if it would be very easy to review, it might be worth the ‘minor’ improvements mentioned above … but I don’t see that combo happening (not on a noticeable scale in gc.cpp).
On a personal note: I also trust CLR team that if all these three things were true, the refactoring would have happened long time ago.

Note that some of this code goes back beyond .NET Core to the .NET Framework, the “historical reasons” that Zikmund mentions. We can see that the factors preventing change are as much organisational as technical.

Finally I attended a session on Microsoft’s Cognitive Services. Note this was in the “Sponsored solution track”. Microsoft also has a stand here focused on its Cognitive Services.

There is not much Microsoft Platform content at QCon and it seems under-represented, though many of the sessions are applicable to developers on any platform. I am not sure of all the reasons for this; there used to be an Advanced .NET track at QCon. It does reflect some overall development trends as well as the history and evolution of QCon itself. That said, there is a session on SQL Server on Linux so the company is not completely invisible here.

As for the session, it was a reasonable overview of Microsoft’s expanding Cognitive Services APIs, which covers things like image recognition, speech recognition and more. I would have liked more depth and would have preferred to hear from a practitioner, in other words, “we built an application on Cognitive Services and this is what we learned.” I am not altogether clear why the company is pushing this so hard, except that it is a driver for developers to use Azure. I asked about how developers should deal with the problem of uncertainty*, in other words, that Cognitive Services does not deliver absolute results but rather draws conclusions with a confidence score – eg it might be pretty sure that an image contains a human face, fairly sure that it is male, and somewhat confident that the age of the person is mid forties. When the speaker demoed speech recognition it went pretty well except that “Start” was transcribed as “Stop.” This stuff is difficult.

Looking forward now to Day Two: Containers, Machine Learning, and more.

*More concisely expressed as “Systems are moving from the deterministic to the probabilistic” by Stephen Whitworth, who is now speaking on Machine Learning.

Microsoft sets Visual Studio LightSwitch to off

Microsoft has officially announced the end of development of LightSwitch, a rapid application builder for desktop and mobile applications.

LightSwitch was introduced in July 2011 as a tool to build multi-tier applications using a data-first approach. You can design you database using an excellent visual designer, design screens for viewing and editing the data using a non-visual designer, and generate applications with the server-side code hosted either on your own server or on Microsoft Azure. The client application in the original LightSwitch was based on Silverlight, but this was later extended with an option for HTML. You can get a feel for the general approach from my early hands-on here.

As I noted at the time, LightSwitch abstracts a number of difficult tasks. This is a good thing, though as with any application generated you had to take time to learn its quirks. That said, it is more usable than most model-driven development tools, in my experience.

LightSwitch had some bad luck. It was conceived at a time when Silverlight looked like the future of Microsoft’s client development platform, but by the time it launched Silverlight was heading for obsolescence. It also fell victim to ideologies within Microsoft (which persist today) that chase the dream of code-free application development that anyone can do. The documentation for LightSwitch on launch was dreadful, a series of how-tos that neglected to explain how the tool worked. You had to get the software development kit, aimed at those building LightSwitch components, to have any hope of understanding the tool.

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The abandonment of LightSwitch is not a surprise. Microsoft had stopped talking about it and adoption was poor. There will be no tooling for it in the next Visual Studio, though you can keep using it for a while if you want.

I think it is a shame since it is a promising tool and I cannot help thinking that with more intelligent positioning and a few tweaks to the product and its documentation it could have been a success. Those who did get to grips with it found it very good.

What is unfortunate is that Microsoft has lost the faith of many developers thanks to the many shifts in its development strategy. I know component vendors have also been caught out by the Silverlight and then LightSwitch debacle. Here is one of the comments on the announcement:

Microsoft keeps doing this over and over, we invest months even years to master a technology, just to find out it’s being phased out prematurely. Perfectly good, one-of-a-kind niche tools too. So much investment on both sides (both MS and customers) down the drain. What’s worse, it is done is a non-transparent, dishonest manner, letting things dry up over a couple years so that when the announcement comes, no-one really cares any more, no more noise – just look at this blog.

This makes it hard for the company to convince developers that its new strategies de jour have a longer life ahead of them. I am thinking of the UWP (Universal Windows Platform), which has already changed substantially since its first conception, and of PowerApps, the supposed replacement for LightSwitch, and yet another attempt to promote code-free development.

Developers do not want code-free development. They like tools that do stuff for them, if they are intuitive and transparent, but they also like an easy route to adding and modifying code in order to have the application work the way they want.

On GitHub and GitHub Universe

I’ve been at GitHub Universe in San Francisco for the last few days. Around 1500 developers (not sure if that figure includes staff and exhibitors) in a warehouse at Pier 70. The venue was beautifully converted into an interaction space. Here is the view from outside as we were leaving; Octocat seems to be waving goodbye:

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The main stage done up like a spaceship:

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There was a large area for mingling, overseen by Octocat:

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Plenty of space outside too, with a high standard of food and drink on offer.

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There was also a “send a postcard” area where you could write a card; with cards, pens, stamps and postbox supplied there was no excuse not to do so:

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You are probably thinking, when do we get to the techie stuff; but in some ways it is better to look at the space GitHub created and ask what it tells you about the company.

Running an event like this is not cheap, and I think we can conclude that GitHub has a business model that works. Further, there was a generous and inclusive spirit to the event which was good to experience. Kimberly Bryant from Black Girls Code spoke at the opening keynote – the event concert was a Black Girls Code benefit – and while there is often an element of PR in the causes which businesses choose to sponsor, I don’t question the authenticity of GitHub’s efforts to promote both coding and diversity in our sadly imbalanced software industry.

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In some ways then the actual technical content was not the most important thing about this event. That said, there was some excellent content on themes including how GitHub scales its own service, new project management and code review features in GitHub, and how the product is evolving its add-in or “integrations” platform.

I also learned a bit about Electron, a framework for “creating native Desktop applications with web technologies” based on Chromium and Node.js. Microsoft’s Visual Studio Code uses Electron, as does GitHub’s own Atom editor.

If you are developer, you will be familiar with GitHub; it is the obvious choice for hosting an open source project (free) and a popular option for private repositories. When Google Code closed in 2015, the announcement cited the migration of developers to GitHub as the key reason and acknowledge that it was among “a wide variety of better hosting services” than Google’s own. “To meet developers where they are, we ourselves migrated nearly a thousand of our own open source projects from Google Code to GitHub,” remarked Google’s Chris DiBona. That was a pivotal moment, showing how GitHub has become a core part of the open source ecosystem as well as a strong commercial product for private and enterprise repositories.

GitHub does seem to take its responsibilities seriously and the fact that is has found a successful balance between free and commercial services is something to be thankful for.

Time for another look at “pure .NET”

Back in the Nineties there was a lot of fuss about “pure Java”. This meant Java code without any native code invocations that tie the application to a specific operating system.

It is possible to write cross-platform Java code that invokes native code, but it adds to the complexity. If it is an operating system API you need conditional code so that the write API is called on each platform. If it is a custom library it will have to be compiled separately for each platform.

Over on the Microsoft .NET site, developers have tended to have a more casual approach. After all, in the great majority of cases the code would only ever run on Windows. Further, Microsoft tended to steer developers towards Windows-only dependencies like SQL Server. After all, that is the value of owning a developer platform.

Times change. Microsoft has got the cross-platform bug, with its business strategy based on attracting businesses to its cloud properties (Office 365 and Azure) rather than Windows. The .NET Framework has been forked to create .NET Core, which runs on Mac and Linux as well as Windows. SQL Server is coming to Linux.

Another issue is porting applications from 32-bit to 64-bit, as I was reminded recently when migrating some ASP.NET applications to a new site. If your .NET code avoids P/Invoke (Platform Invoke) then you can compile for “Any CPU” and 64-bit will just work. If you used P-invoke and want to support both 32-bit and 64-bit it requires more care. IntPtr, used frequently in P/Invoke calls, is a different size. If you have custom native libraries, you need to compile them separately for each platform. The lazy solution is always to run as 32-bit but that is a shame.

What this means is that P/Invoke should only be used as a last resort. Arguably this has always been true, but the reasons are stronger today.

This is also an issue for libraries and components intended for general use, whether open source or commercial. It is early days for .NET Core support, but any native code dependencies will be a problem.

Breaking the P/Invoke habit will not be easy but “Pure .NET” is the way to go whenever possible.

Reflections on QCon London 2016 – part one

I attended QCon in London last week. This is a software development conference focused on large-scale projects and with a tradition oriented towards Agile methodology. It is always one of the best events I get to attend, partly because it is vendor-neutral (it is organised by InfoQ), and partly because of the way it is structured. The schedule is divided into tracks, such as “Back to Java” or “Architecting for failure”, each of which has a track leader, and the track leader gets to choose who speaks on their track. This means you get a more diverse range of speakers than is typical; you also tend to hear from practitioners or academics rather than product managers or evangelists.

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The 2016 event was well up to standard from my perspective – though bear in mind that with 6 tracks on each day I only got to attend a small fraction of the sessions.

This post is just to mention a few highlights, starting with the opening keynote from Adrian Colyer, who specialised in finding interesting IT-related research papers and writing them up on his blog. He seems to enjoy being contrarian and noted, for example, that you might be doing too much software testing – drawing I guess on this post about the art of testing less without sacrificing quality. The takeaway for me is that it is always worth analysing what you do and trying to avoid the point where the cost exceeds the benefit.

Next up was Gavin Stevenson on “love failure” – I wrote this up on the Reg – there is a perhaps obvious point here that until you break something, you don’t know its limitations.

On Monday evening we got a light-hearted (virtual) look at Babbage’s Analytical Engine (1837) which was never built but was interesting as a mechanical computer, and Ada Lovelace’s attempts to write code for it, thanks to John Graham-Cumming and illustrator Sydney Padua (author of The Thrilling Adventures of Lovelace and Babbage).

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Tuesday and the BBC’s Stephen Godwin spoke on Microservices powering BBC iPlayer. This was a compelling talk for several reasons. The BBC is hooked on AWS (Amazon Web Services) apparently and stores 21TB daily into S3 (Simple Storage Service). This includes safety copies. iPlayer was rebuilt in 2013, Godwin told us, and the team of 25 developers achieves 34 live deployments per week on average; clearly the DevOps stuff is working here. Godwin advocates genuinely “micro” services. “How big should a microservice be? For us, about 600 Java statements,” he said.

Martin Thompson spoke on the characteristics of a good software engineer, though oddly the statement that has stayed with me is that an ORM (Object-Relational Mapping) “is the wrong abstraction for a database”, something that chimes with me even though I get the value of ORMs like Microsoft’s Entity Framework for rapid development where database performance is non-critical.

Then came another highlight: Google’s Micah Lemonik on Architecting Google Docs. This talk sadly was not recorded; a touch of paranoia from Google? This was fascinating both from a historical perspective – Lemonik was involved in a small company called 2Web technologies which developed an Excel-like engine in 2003-4, and joined Google (which acquired 2Web) in 2005 to work on Google Sheets. The big story here was the how Google Sheets became collaborative, so more than one person could work on a spreadsheet simultaneously. “Google didn’t like it initially,” said Lemonik. “They thought it was too weird.” The team persisted though, thinking about the editing process as “messages being transferred between collaborators” rather than as file updates; and it worked.

You can actually use today’s version in your own projects, with Google’s Realtime API, provided that you are happy to have your stuff on Google Drive.

I particularly enjoyed Lemonik’s question to the audience. Two people are working on a sheet, and one types “6” into a cell. Then the same person overtypes this with “7”. Then the collaborator overtypes the same cell with “8”. Next, the first person presses Ctrl-z for undo. What should be the result?

The audience split neatly into “6”, “7”, and just a few “8” (the rationale for “8” is that undo should only undo your own changes and not touch those made by others).

Google, incidentally, settled on “6”, maintaining a separate undo stack for each user. But there is no right answer.

Lemonik also discussed the problem of consistency when there are large numbers of contributors. A hard problem. “There have to be bounds to the system in order for it to perform well,” he said. “The biggest takeaway for me in building the system is that you just can’t have it all. All of engineering is this trade-off.”

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I have more to say about QCon so look out for part two shortly.