Servicing comes to the Slow Ring (and why that’s big news)

Something very interesting has happened to Windows 10 Insiders Preview builds in the Slow Ring over the past few months: They’re being released more regularly — and with increased reliability.

It’s all part of a commitment we made earlier this year to start servicing the Windows Insider Slow Ring. This is especially good news for businesses who use the Insider Preview builds to get an early start on their Windows validation efforts — and this good news is only going to get better. Read on.

First, a quick word about Rings.

Insider Preview builds are released to Insiders in three rings: Fast, Slow and Release Preview. If you have devices in the Fast Ring, you’re getting our earliest Insider Preview builds. The Fast Ring is a great place to explore next features — but there is potential for issues.

At the other end of the ring spectrum is Release Preview which is essentially the current public branch of Windows 10 but with early access to updates, applications, and drivers.

Builds in the Slow Ring are ideal for users who want to see new features but not run the risk of really bad issues. It provides new updates and features but are more stable than builds in the Fast Ring. This makes the Slow Ring an ideal place to for both feature exploration, longer running validation tests as well as app and infrastructure validation.

The problem is that getting Fast Ring builds up to Slow Ring quality often took us longer than we anticipated. Adding to the delays — the builds we created to fix bugs would sometimes introduce new bugs or regressions.

Sure, as we approached the end of a development cycle and the quality of builds increased, we could also increase the frequency of our Slow build releases. But we wanted to get builds out to Insiders earlier to maximize their testing window. At the same, we also wanted to ensure that every build was stable enough to run on a day-to-day basis without losing productivity.

To achieve both objectives, it was clear that we needed to do things differently.

Servicing to the rescue!

Several months ago at our Microsoft Build event, we made an important announcement: Windows 10 Insider Preview builds in the Slow Ring would now be serviced. Not only that, they would be serviced using the same tools and processes we used to support our production releases.

Instead of using feature updates (that is, entirely new builds) to address bugs, we would now create fixes, package them up as Quality Updates and release them along with the Feature Update. It took some time to refine the process, but the big bet paid off. Bugs are now caught sooner, fixed faster — so stable builds can be released earlier. Here’s how the system works:

  1. We evaluate the quality of flights in Fast. We look at the quality of Fast Ring flights on a daily basis using feedback from internal selfhosting and Insiders.
  2. We triage any proposed bugs blocking Slow. We send bugs blocking a Slow Ring release to the feature teams who get issues fixed and into the branch in 3-5 days. Once checked in, the fixes are packaged into a latest cumulative update (LCU).
  3. We test and deliver the serviced Slow build to Insiders. We do another round of internal selfhost testing of the build with the LCU fixes to make sure everything works. The Feature Update and service packages (quality update) are then delivered to the Slow ring at the same time.

Steps showing from Fast ring, to Fixed, to Slow ring

What this all means for Insiders.

With the new servicing mechanism, we can now deliver several benefits to Windows Insiders:

  • We can stabilize a Fast Ring build even in the early stages of a release cycle — and send it to the Slow Ring right way. In fact, you’ll start seeing builds in the Slow Ring earlier than ever before in our upcoming new «19H1» release cycle.
  • All builds will receive the latest Microsoft Security Response Center (MSRC) security fixes shortly after public availability. We will align to InMarket “B” releases — aka Patch Tuesday build.
  • We can commit that, once a month, we will select a build and ‘stabilize’ it with selective fixes in a short timeframe to bring it up to the quality needed for the Slow Ring.
  • We will aspire to take all FAST builds to SLOW if they meet the quality bar.

And we’re not done yet. We continue to refine our servicing mechanisms for even greater speed and stability in the Slow Ring. We’re also making updates smaller and even easier to deploy.

The bottom line: now more than ever, Insider Preview builds are an ideal way to get a head start on your next Windows deployment. Starting by take a fresh look at your Windows as a Service strategy. Use the Slow Ring builds on at least 1% of your devices to effectively validate apps and infrastructure. Then get set to reap even more from your Windows investment.

As you’ll quickly discover, it pays to think Slow.