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Relatively General .NET

Recording

by Oren Eini

posted on: March 05, 2024

When Oren Eini originally developed RavenDB, he used the Lucene library to implement indexing. Eventually, his team encountered limitations with this strategy, so they created the Corax search engine, which improved query execution time significantly. Oren discusses the challenges involved in creating this engine and the approaches they took to overcome these challenges.Part 1:Part 2:

RavenDB Cloud Global Status vs. Product Status

by Oren Eini

posted on: March 04, 2024

One of the interesting components of RavenDB Cloud is status reporting. It turns out that when you offer X as a Service, people really care about your operational status. For RavenDB Cloud, we have https://status.ravendb.net/, which will give you some insights into the overall health of the system. Here are some details from the status page:   The interesting thing about this page is that it shows global status, indicating issues affecting large swaths of users. For instance, Azure having issues in a whole region in the image above is a great example of one such scenario. Regular maintenance, which we carry over the span of days, is something that we report, but you’ll usually never notice (due to the High Availability features of RavenDB). It gets more complicated when we start talking about individual instances. There are many scenarios where the overall system health is great, but a particular database may suffer. The easiest example is if you run out of disk space. That affects that particular instance only. For that scenario, we are reporting Production Monitoring Alerts within the RavenDB Cloud portal. Here is what this looks like:     As you can see, we report specific problems on those instances, raising that to your awareness. That was actually needed because, for the most part, RavenDB itself handles those sorts of things via High Availability, which means that even if there are issues, you’re likely to not feel them for a while. Resilience at the cluster level means that even pretty severe problems are papered over and the system moves on. But there is only so much limping that you can do. If you are running at the bare edge of capacity, eventually you’ll trip over the line. Those Production Monitoring Alerts allow you to detect and act upon those issues when they happen, not when they bring down production. This aligns with our vision for RavenDB, the kind of system where you don’t need to have a full-time babysitter monitoring the system. Instead, if there is a problem that the database cannot solve on its own, it will explicitly notify you, in advance. That leads to a system that is far healthier all around and means that you can focus on building your system, rather than managing database minutiae.

Optional parameters may appear in the middle of the parameter list

by Gérald Barré

posted on: March 04, 2024

In .NET, optional parameters are not always the last parameters. While C# does not allow the declaration of optional parameters in the middle of the parameter list, it is possible to do so in IL or from other languages like VB.NET or F#. Also, the compiler may lower some features and create methods

.NET MAUI Community Toolkit 2023 Highlights

by Kym Phillpotts

posted on: February 29, 2024

Let's take a look back at all the happeneings from 2023 for the the .NET MAUI Community Toolkit's Journey of Growth, Rich Features, and Expanding Community Collaboration and a sneak peak at what is next.

The FAST and the Fluent: A Blazor story

by Vincent Baaij

posted on: February 26, 2024

Learn about the origin of the building blocks of the Fluent UI Blazor library. We'll talk about FAST, Web Components, Fluent Design, and more.

Enable AutoLogin in Windows using .NET

by Gérald Barré

posted on: February 26, 2024

If you need to enable AutoLogin in Windows, you can use the registry. However, the password is stored in clear text. It's not a good idea to store a password in clear text. Instead, you can use the LSA to encrypt the password. Note that this is what SysInternals Autologon does. Also, note that the

RavenDB, Raspberry Pi & Hugin Appliance: oh my!

by Oren Eini

posted on: February 23, 2024

RavenDB can run on the Raspberry Pi, it is actually an important use case for us when our users are deploying RavenDB as part of Internet of Things systems. We wanted to showcase RavenDB’s performance and decided that instead of scaling up and showing you how well RavenDB does ridiculous loads, we’ll go the other way around. We’ll go small, and let you directly experience how efficient RavenDB is.You can look at the demo unit directly on this page.We decided to dial it down yet further, and run RavenDB on the Raspberry Pi Zero. This tiny computer is about the size of a cigarette lighter and is small enough to comfortably fit on your keychain. Most Raspberry Pis are impressive machines given their cost, more than powerful enough to power real applications.Here is what this actually looks like, with me as a reference for size 🙂.However, just installing RavenDB on the Zero isn't much of a challenge or particularly interesting, to be honest. We wanted to do something that would be both fun and useful. One of the features we want users to explore is the ability to run RavenDB in appliance mode. The question is, what sort of an appliance will we build?A key part of our thinking was that we wanted to show something that works with realistic data sizes. We wanted to have an actual use case for this, beyond just showing a toy. One of the things that I always find maddening about being disconnected is that I feel like half my brain has been cut away. We set out to fix that, the project is to create a knowledge system inside the Pi Zero that would be truly Plug & Play. That turned out to be quite a challenge, but I think we met it in a very nice manner.We went to archive.org and got some of the Stack Exchange data sets. In particular, we got the datasets that are most interesting for DevOps scenarios. In particular, we have raspberrypi.stackexchange.com, unix.stackexchange.com, serverfault.com, and superuser.com.I find it deliciously recursive that we can use the Raspberry Pi Zero to store the dataset about the Raspberry Pi itself. We loaded all those datasets into the Zero, for a total of about 7.5 GB, and over 4.2 million documents were stored there.Note that this is using RavenDB’s document compression, which reduced the total size by over 50% over the original dataset size. Next was the time to actually make this accessible. Just working with RavenDB directly to query the data is cool, for sure, but we wanted to be useful.So we built a portal to access the data. Here is what it looks like when you enter it for the first time:We offer full search capabilities and complete offline access to all those data sets. Perfect when you are stuck in the middle of nowhere and urgently need to remember that awk syntax or how to configure networking on a stubborn device. Another aspect that we have to consider is how this can work? The Raspberry Pi Zero is a tiny device, and actually working with it can be annoying. It needs Micro-USB power but has no ethernet or standard USB ports. For display, it uses a mini HDMI port. That means that you can safely assume that you’re likely to have a power cable for it, but not much else. We want to provide a good solution, so what do we do? The Raspberry Pi Zero we use does have a wifi chip, so we took things further and set it up as an access point with a captive portal.You can read exactly how we configured that in this post.In other words, the expected deployment model is to plug this into power, wait 30 seconds for the machine to boot, and then connect to the “Hugin” wireless network. You will then land directly into the application, able to deep dive into the questions of your choice.We have been giving away those appliances at the DevWeek conference, and we got a really good reaction from users. Beyond the coolness factor, the fact that we can run a high-performance system on top of a… challenging hardware platform (512MB RAM, 1Ghz RAM, SD Card for disk) and still provide sub-100ms response times is quite amazing.You can view the project page here, the entire thing is Open Source, and you can explore how we are able to do that on GitHub.