Cloud Witness in Windows Server v.Next

Last week, I attended the session “Did you vote today? A DBA’s guide to cluster quorum” at PASS Summit, by Allan Hirt.
Interesting stuff, and I learned that my quorum configuration is already done correctly according to what Allan explained.

Another interesting part was that Allan announced that there is a new type of quorum in Windows Server v.Next.

Cloud Witness!

Instead of using a File Share Witness or Disk Witness, you can now also choose Cloud Witness.
Basically it’s going to create a file on your Azure Storage which counts as a quorum vote.
This cloud witness can be really helpful in case of multi-site clusters.
With multi-site clusters, there is always the question in which datacenter you are going to put the file share witness.
In fact, to configure it correctly, you should put your file share witness in a third datacenter. But that’s really too expensive for most companies just for a file share witness. The cloud witness provides a good alternative for this problem.

The only “issue” that I see with this cloud witness, is that your cluster nodes must have connection with the internet. And honestly, I haven’t seen much SQL Servers or cluster nodes that are able to connect to the internet.
But with the appropriate firewall settings, you should be OK.

I’ve already installed a 2 node Windows vNext Failover Cluster and tried it out.
It’s actually really easy to configure.

Start with opening the Failover Cluster Manager and connect to your cluster.
Right click on the cluster name à More Actions à Configure Cluster Quorum Settings…

In the “Select Quorum Configuration Option” windows, select “Select the quorum witness”

In the “Select Quorum Witness” windows, select “Configure a cloud witness”

To configure the cloud witness, you need to specify your storage account and your Azure storage account key.

This information can be found on the Azure Portal. Just go to the storage option. On the bottom of your screen you will see a button called Manage Access Keys.

Click on that button, copy one of the 2 keys and paste it in the Azure storage field of the cloud witness configuration

Your configuration should look similar like this screen shot below

Finally, complete the wizard and if all went well you have now configured your cloud witness.

When you look at your storage account in the Azure Portal, you will notice that a new container, “msft-cloud-witness”, is created with 1 blob file inside.

Pretty cool if you ask me 😀 !

Pieter

 

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