Last week, Microsoft released Windows 10 Insider Preview build 17723 to the Fast ring, along with the first new Skip Ahead build from the 19H1 development branch. As usual, the company is releasing a new Windows Server 2019 and SDK Insider Preview with the same build number on the following Tuesday.
Windows Server 2019 build 17723 replaces build 17713, which was released exactly two weeks ago. Unlike that one, there are actually some new features. It's still focused on in-place OS upgrades from Windows Server 2012 R2 or Windows Server 2016, and application compatibility.
In this Insider build, you can add new predictive capabilities to System Insights, without requiring any OS updates. This functionality enables developers, including Microsoft and third parties, to create and deliver new capabilities mid-release to address the scenarios you care about. New developer documentation and resources are now available, which help you write your own custom capabilities.
Any new capability can integrate with and extend the existing System Insights infrastructure:
- New capabilities can specify any performance counter or ETW event, which will be collected, persisted locally, and returned to the capability for analysis when the capability is invoked.
- New capabilities can leverage the existing Windows Admin Center and PowerShell management planes. Not only will new capabilities be discoverable in System Insights, they also benefit from custom schedules and remediation actions.
Deploying Kubernetes on Windows Server
Kubernetes is a popular orchestration tool for containers (see What are Containers) that makes deployment and management intuitive, scalable, and effective. This includes built-in features such as:
- Scheduling: Given a container image and a resource request, find a suitable machine on which to run the container.
- Health monitoring: Watch for container failures and automatically reschedule them.
- Networking: Provide a network for coordinating containers to communicate across machines.
- Service Discovery: Enable containers to locate each other automatically even as they switch hosts or change IP addresses.
- Scaling: Add or remove container instances to match demand, either manually or automatically.
And much more! For guidance that walks you through how to install Kubernetes onto your on-premise Windows datacenter, please see How To Guide: Kubernetes for Windows Flannel (Host-Gateway). For more information about container orchestrators in general, see Container orchestrators on docs.microsoft.com.
Congestion Control with LEDBAT
Keeping a network secure is a never-ending job for IT Pros, and doing so requires regularly updating systems to protect against the latest threat vectors. This is one of the most common tasks that an IT Pro must perform. Unfortunately, it can result in dissatisfaction for end-users as the network bandwidth used for the update can compete with interactive tasks that the end user requires to be productive.
With Windows Server 2019, we bring a latency optimized, network congestion control provider called LEDBAT which scavenges whatever network bandwidth is available on the network, and uses it
For a full write up detailing this improvement, please see our announcement LEDBAT – Latency Optimized Background Transport
There are also some known issues to be aware of:
[NEW] On Nano Server, copying a file from an SMB volume in a container to local storage fails.
[NEW] A specific distributed search and analytics engine may by denied access when querying C:\Windows\temp\ as ContainerUser. To work around this issue, set the paths for temporary folders to another location. For example, by using setx: setx /M TEMP “c:\sample” setx /M TEMP “c:\sample”
[NEW] A Multi-Resilient Volume (MRV) may fail to mount during node maintenance for a software-defined datacenter (SDDC) cluster, causing virtual machines to go offline.
[NEW] Services.exe should not launch Upfc.exe when a system starts if the system is running inside of a container.
[NEW] On recent preview builds, database applications might not be able to initialize a database and fail with a stack overflow or insufficient privileges when the database is located on an SMB volume.
[NEW] Virtual machines stop unexpectedly with exit reason 3, and they migrate repeatedly every few minutes.
[NEW] Preview releases of the operating system, starting with build 17698, may fail to detect a specific family of RAID controllers.
[NEW] Shielded VMs running Linux do not boot. The loader (LSVMLoad) waits for a passphrase for the boot partition.
[NEW] Draining a node may fail with an error: “Cannot create a file when that file already exists. (0x800700b7).”
Creating or modifying environment variables by using setx fails on a system running in a Nano Container (that is, Nano Server as a container image). On an affected system, setx requires a specific path in the registry, HKCU\Environment\, to exist by default. You can work around this issue by changing where the variable is stored in the registry, or you can add the expected registry path before executing setx commands. To specify that the variable be set for system-wide use in HKLM rather than in HKCU, the default, add the /M switch to a setx command. To instead add the expected registry path, run reg add HKCU\Environment before executing setx commands.
The Virtual Machine Management Service (VMMS) may experience an error, APPLICATION_FAULT_INVALID_POINTER_READ, in Cluster Manager.