Technical Preview 3 Archives

August 20, 2015

The Setup Experience in Windows Server 2016 Technical Preview 3

Yesterday I blogged about one of the most important features in Windows Server 2016 Technical Preview 3 and how it affects SQL Server – domainless WSFCs. I am genuinely stoked for that feature because it will open up some scenarios we have never been able to do with clusters. There are other cluster-related enhancements I will be writing about, but today is not that day.

A few months ago, I wrote a blog post entitled Need a User Interface for Windows Server Technical Preview 2? It’s Not On By Default. The title is self explanatory. With TP2, you had two installation options: Server Core and Min Shell. Since then, Microsoft listened to many of us and put a GUI option into Setup for TP3. Unfortunately, it was a course correction too much to the left. When you are installing Windows Server 2016 TP3, you get two options as shown in Figure 1: Windows Server 2016 Technical Preview 3, which is Server Core, and an option that is Server with Desktop Experience.

Figure 1. Windows Server 2016 TP3 Installation Options

Hold the phone – Desktop Experience? Is my Server now a client OS? No!

Prior to Windows Server 2016, when you got a GUI for Windows Server, it was not Desktop Experience. Desktop Experience brings with it things like the cool Tron-like Windows background. Along for the ride are other things – like Media Foundation and Ink and Handwriting. Lord knows I need to use my N-trig pen on a server (NOT)!

Of course, you can simply run Remove-WindowsFeature Desktop-Experience and get rid of it, but why should we have to do extra work? A server OS – or any OS for that matter – should just work the way it should out of the box. The problem is, removing Desktop Experience does not remove things like Ink and Handwriting in TP3. In fact, you can’t remove them at all via the GUI as shown in Figure 2.

Figure 2. Cannot remove UI features via Server Manager

PowerShell to the Rescue! If you run the following command:

Remove-WindowsFeature Server-Media-Foundation,InkAndHandwritingServices

it turns out you can remove them. So if you want to get rid of everything at once, just add Desktop-Experience and another comma. Reboot and you’re all set. Figure 3 reflects the feature removal in the GUI post-reboot.

Figure 3. UI after using PowerShell to remove features

You can also switch to MinShell or Server Core if you’d like via PowerShell as well.

I really do like a lot of what Windows Server 2016 is bringing to the table, but as I have always stated, Setup is your first introduction to any product. Make it a miserable experience, and people will not be starting off on a good foot. While I’m excited to use Windows Server 2016 and get my customers on it because of some of the benefits, this is putting a damper on the overall experience. But, it has to be said, at least Microsoft is listening. They put a GUI option back in … just the wrong one. Ideally Microsoft should give us three installation options for Windows Server:

Server Core
MinShell
Full UI (but not Desktop Experience, Ink and Handwriting Services, and Media Foundation)

That way admins can pick the OOB experience they want without any additional work.

At least Microsoft is listening to us and they made a well intentioned, but IMO misguided, change to the TP3 Setup experience. We will see what the next release brings …

August 19, 2015

SQL Server Availability Group Configurations With NO Domain Requirement

You may have noticed that Windows Server 2016 Technical Preview 3 was released today. For the full announcement from Microsoft on the Server & Cloud blog, click here. There is one important line that all SQL Server folks should pay attention to:

Increase flexibility by removing domain-specific constraints for SQL Server clusters

Yes, kids. That means you can create a Windows Server Failover Cluster (WSFC) with NO – I repeat NO – domain required. This will not work for clustered instances (FCIs) since they still require domain-based service accounts, but it will work and be supported with SQL Server 2016 for AlwaysOn Availability Groups (AGs). I would not expect Microsoft to go back and certify this configuration with SQL Server 2014 (or 2012 for that matter), but you never know. If you try and want to use 2012 or 2014 in this configuration, as of the posting of this blog post, it would be considered unsupported – don’t do that as it is the antithesis of mission critical.

This is huge and for many, will simplify AG configurations. No more CNOs and VCOs (although this was possible in Windows Server 2012 R2, you still needed the nodes to be domain joined). I have been testing this configuration with SQL Server 2016 CTP 2.2 and the builds of Windows Server 2016, but due to NDA, have not been able to talk about it until today because it had not been publicly announced. For everyone who has been complaining how DBM was better, you got your wish – this allows you to have an AG configuration which is the same as the one that you had using database mirroring (DBM) with certificates.

The demo configuration I will show below is multi-subnet to simulate two different data centers. Node One (SYLVESTER) is in subnet one and Node Two (TWEETY) is in subnet two. These are not joined to any domain as shown in Figures 1 and 2.

Figure 1. Sylvester not joined to a domain

Figure 2. Tweety is also not domain joined

So far, so good. My WSFC’s name is PUDDYTAT. The entire configuration can be seen in Figure 3.

Figure 3. WSFC info

I have an AG named AG1 with a Listener named GRANNY. Its info is in Figure 4.

Figure 4. AG info in the WSFC

While you can see that the AG is up and running in Figure 4, Figure 5 shows it working in SSMS. Viola!

Figure 5. AG working with no domain

If you don’t believe me yet, to further drive the point home, I left the accounts running the SQL Server instances as local accounts (NT Service\MSSQLSERVER and NT Service\SQLSERVERAGENT). This can be seen in Figure 6. Figure 6 also shows the properties of SQL Server where the ability to use AGs is enabled. This is very real and works as advertised. I’m excited about this.

Figure 6. Local service accounts but still joined to a WSFC

As always, there are some caveats to this configuration that you should be aware of:

At least in TP3, you cannot create or administer the WSFC via Failover Cluster Manager. Everything must be done in PowerShell. This may not change between now and RTM of Windows Server 2016, so if you are uncomfortable administering clusters via PowerShell, this is not a configuration you should be using. If you try to use Failover Cluster Manager, you will see the message in Figure 7.

Figure 7. Cannot use FCM in a non-domain scenario

This will make using the AG Wizard to do your backups a bit trickier since shared directories usually use domain-based accounts. You may have to manually deal with them if you are not using domains or do not have trusted domains.
There are some flags that get tripped during Cluster Validation (namely, no domain) that should be fixed by RTM. This is a known issue in TP3.
With no domain requirement, this also means no Kerberos however, if each node is in a different domain (i.e. one in Site, another domain in Site B) but crosses boundaries, you should be able to have Kerberos. I have not tested this configuration yet (it is on my list). This should even enable cross-domain migrations – again a scenario I have yet to test. There are more, but hey, first blog post and all of that.
You will need to add the DNS suffix manually otherwise the WSFC will not come online
Networking is clearly crucial here, and things like DNS replication will be important.
File Share Witness is not supported, so you will need to use asymmetric disk (which defeats the purpose of AGs with no shared storage) or Cloud Witness.

The good news is now that this is public, this bit will most likely make it into the book. I wanted to do a quick blog on it, and if I get time, I will show how I created this in a blog post soon. Also, with this now public, I may make this one of the labs for my PASS Summit 2015 preconference session Advanced SQL Server Availability Architectures and Deployments. Sign up now!

UPDATE: I just saw that Subhasish of the Cluster team on Windows just blogged a bit more about the Windows side of this.

Also, due to the fact that the AG configuration is standalone with no storage and there was an error during validation (TP3 known issue I mention above) due to the fact these are not domain joined, I used the -Force and -NoStorage options of New-Cluster.

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