STEP-BY-STEP: HOW TO CONFIGURE A SQL SERVER 2008 R2 FAILOVER CLUSTER INSTANCE ON WINDOWS SERVER 2008 R2 IN AZURE OR AZURE STACK

Intro

On July 9, 2019, support for SQL Server 2008 and 2008 R2 will end. That means the end of regular security updates. However, if you move those SQL Server instances to Azure or Azure Stack (I will simply refer to both as Azure for the rest of the guide), Microsoft will give you three years of Extended Security Updates at no additional charge. If you are currently running SQL Server 2008/2008 R2 and you are unable to update to a later version of SQL Server before the July 9th deadline, you will want to take advantage of this offer rather than running the risk of facing a future security vulnerability. An unpatched instance of SQL Server could lead to data loss, downtime or a devastating data breach.

One of the challenges you will face when running SQL Server 2008/2008 R2 in Azure is ensuring high availability. On premises you may be running a SQL Server Failover Cluster (FCI) instance for high availability, or possibly you are running SQL Server in a virtual machine and are relying on VMware HA or a Hyper-V cluster for availability. When moving to Azure, none of those options are available. Downtime in Azure is a very real possibility that you must take steps to mitigate.

In order to mitigate the possibility of downtime and qualify for Azure’s 99.95% or 99.99% SLA, you have to leverage SIOS DataKeeper. DataKeeper overcomes Azure’s lack of shared storage and allows you to build a SQL Server FCI in Azure that leverages the locally attached storage on each instance. SIOS DataKeeper not only supports SQL Server 2008 R2 and Windows Server 2008 R2 as documented in this guide, it supports any version of Windows Server, from 2008 R2 through Windows Server 2019 and any version of SQL Server from from SQL Server 2008 through SQL Server 2019.

This guide will walk through the process of creating a two-node SQL Server 2008 R2 Failover Cluster Instance (FCI) in Azure, running on Windows Server 2008 R2. Although SIOS DataKeeper also supports clusters that span Availability Zones or Regions, this guide assumes each node resides in the same Azure Region, but different Fault Domains. SIOS DataKeeper will be used in place of the shared storage normally required to create a SQL Server 2008 R2 FCI.

Pre-Requisites

Active Directory
This guide assumes you have an existing Active Directory Domain. You can manage your own Domain Controllers or use Azure Active Directory Domain Services. For this tutorial we will connect to a domain called contoso.local. Of course you will connect to your own domain when following this tutorial.

Open Firewall Ports
– SQL Server:1433 for Default Instance
– Load Balancer Health Probe: 59999
– DataKeeper: these firewall rules are added to the Windows host based firewall automatically during installation. For details on which ports are opened consult the SIOS documentation.
– Keep in mind, if you have any network based security in place that blocks ports between the cluster nodes you will need to account for these ports there as well.

DataKeeper Service Account
Create a Domain account. We will specify this account when we install DataKeeper. This account will need to be added to the Local Administrators group on each node of the cluster.

Create the first SQL Server Instance in Azure

This guide will leverage the SQL Server 2008R2SP3 on Windows Server 2008R2 image that is published in the Azure Marketplace.

When you provision the first instance you will have to create a new Availability Set. During this process be sure to increase the number of Fault Domains to 3. This allows the two cluster nodes and the file share witness each to reside in their own Fault Domain.

If you don’t already have a virtual network configured, allow the creation wizard to create a new one for you.

Once the instance is created, go in to the IP configurations and make the Private IP address static. This is required for SIOS DataKeeper and is best practice for clustered instances.

Make sure that your virtual network is configured to set the DNS server to be a local Windows AD controller to ensure you will be able to join the domain in a later step.

After the virtual machines are provisioned, add at least two additional disks to each instance. Premium or Ultra SSD are recommended. Disable caching on the disks used for the SQL log files. Enable read-only caching on the disk used for the SQL data files. Refer to Performance guidelines for SQL Server in Azure Virtual Machines for additional information on storage best practices.

Create the 2nd SQL Server Instance in Azure

Follow the same steps as above, except be sure to place this instance in the same virtual network and Availability Set that you created with the 1st instance.

Create a File Share Witness (FSW) Instance

In order for the Windows Server Failover Cluster (WSFC) to work optimally you are required to create another Windows Server instance and place it in the same Availability Set as the SQL Server instances. By placing it in the same Availability Set you ensure that each cluster node and the FSW reside in different Fault Domains, ensuring your cluster stays on line should an entire Fault Domain go off line. This instances does not require SQL Server, it can be a simple Windows Server as all it needs to do is host a simple file share.

This instance will host the file share witness required by WSFC. This instance does not need to be the same size, nor does it require any additional disks to be attached. It’s only purpose is to host a simple file share. It can in fact be used for other purposes. In my lab environment my FSW is also my domain controller.

Uninstall SQL Server 2008 R2

Each of the two SQL Server instances provisioned already have SQL Server 2008 R2 installed on them. However, they are installed as standalone SQL Server instances, not clustered instances. SQL Server must be uninstalled from each of these instances before we can install the cluster instance. The easiest way to do that is to run the SQL Setup as shown below.

When you run setup.exe /Action-RunDiscovery you will see everything that is preinstalled

setup.exe /Action=RunDiscovery

Running setup.exe /Action=Uninstall /FEATURES=SQL,AS,RS,IS,Tools /INSTANCENAME=MSSQLSERVER kicks off the uninstall process

setup.exe /Action=Uninstall /FEATURES=SQL,AS,RS,IS,Tools /INSTANCENAME=MSSQLSERVER

Running setup.exe /Action-RunDiscovery confirms the uninstallation completed

setup.exe /Action-RunDiscovery

Run this uninstallation process again on the 2nd instance.

Add instances to the Domain

All three of these instances will need to be added to a Windows Domain. As mentioned in the Prerequisites section, you must have access to join an existing Windows Active Directory. In our case, we are joining a domain called contoso.local.

Add Windows Failover Clustering Feature

The Failover Clustering Feature needs to be added to the two SQL Server instances

Add-WindowsFeature Failover-Clustering

Install Convenience Rollup Update for Windows Server 2008 R2 SP1

There is a critical update ( kb2854082) that is required in order to configure a Windows Server 2008 R2 instance in Azure. That update and many more are included in the Convenience Rollup Update for Windows Server 2008 R2 SP1. Install this update on each of the two SQL Server instances.

Format the Storage

The additional disks that were attached when the two SQL Server instances were provisioned need to be formatted. Do the following for each volume on each instance.

Microsoft best practices says the following…

“NTFS allocation unit size: When formatting the data disk, it is recommended that you use a 64-KB allocation unit size for data and log files as well as TempDB.”

Run Cluster Validation

Run cluster validation to ensure everything is ready to be clustered.

Import-Module FailoverClusters
Test-Cluster -Node "SQL1", "SQL2"

Your report will contain WARNINGS about Storage and Networking. You can ignore those warnings as we know there are no shared disks and only a single network connection exists between the servers. You may also receive a warning about network binding order which can also be ignored. If you encounter any ERRORS you must address those before you continue.

Since there are no “Potential Cluster DIsks” available, the first test throws a warning and all the subsequent disks test are skipped. This is expected since we will be using just local disks replicated with SIOS DataKeeper.
The Validate Network Communication tests warn about just a single network being available between cluster nodes. You can ignore this warning since the network redundancy is handled at the virtual layer by Azure.

Error trying to run Cluster Validation?

I have encountered this error on a few occasions and I’m still trying to sort out under what conditions this occurs. Occasionally you will find that test-cluster fails to run as described in the forum post.

Test-Cluster
Unable to Validate a Cluster Configuration. The operation has failed. The action validate a configuration did not complete
There is an error in XML document (5, 73).  

Attempt by method

Microsoft.Xml.Serialzation.GeneratedAssembly.XmlSerialzationReaderClusterPrep.Config.Read4_As...Bolean) to access method

MS.Internal.ServerClusters.Validation.TestAssemblyCollection.Add(MS.Internal.ServerClusters.V....Failed

If this happens to you, I have found the following fix recommended in the forum post works for me.

Inside C:\Windows\System32\WindowsPowerShell\v1.0 make a copy of powershell_ise.exe.config file (make a copy inside C:\Windows\System32\WindowsPowerShell\v1.0)- rename it to powershell.exe.config

Open it with notepad- delete current config line and paste:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <system.xml.serialization>
    <xmlSerializer useLegacySerializerGeneration="true"/>
  </system.xml.serialization>
</configuration>
- save and run test-cluster

While this fix will allow you to run test-cluster from Powershell, I have found that running Validate through the GUI still throws an error, even with this fix. I have a query in to Microsoft to see if they have a solution, but for now if you need to run cluster Validation you may have to use Test-Cluster in Powershell.

Create the Cluster

Best practices for creating a cluster in Azure would be to use Powershell to create a cluster, specifying a static IP address. Powershell allows us to specify a Static IP Address, whereas the GUI method does not. Unfortunately, Azure’s implementation of DHCP does not work well with WSFC, so if you use the GUI method you will wind up with a duplicate IP address as the Cluster IP Address that will need to be fixed before the cluster is usable.

However, what I have found is that the typical New-Cluster powershell command with the -StaticAddress command doesn’t work. To avoid the problem of the duplicate IP address, we have to resort to the cluster.exe utility and run the following command.

cluster /cluster:cluster1 /create /nodes:"sql1 sql2" /ipaddress:10.0.0.100/255.255.255.0

Add the File Share Witness

Next we need to add the File Share Witness. On the 3rd server we provisioned as the FSW, create a folder and share it as shown below. You will need to grant the Cluster Name Object (CNO) read/write permissions at both the Share and Security levels as shown below.

Once the share is created, run the Configure Cluster Quorum wizard on one of the cluster nodes and follow the steps illustrated below.

Install DataKeeper

Install DataKeeper on each of the two SQL Server cluster nodes as shown below.

This is where we will specify the Domain account we added to each of the local Domain Administrators group.

Configure DataKeeper

Once DataKeeper is installed on each of the two cluster nodes you are ready to configure DataKeeper.

NOTE – The most common error encountered in the following steps is security related, most often by pre-existing Azure Security groups blocking required ports. Please refer to the SIOS documentation to ensure the servers can communicate over the required ports.

First you must connect to each of the two nodes.

If everything is configured properly, you should then see the following in the Server Overview report.

Next, create a New Job and follow the steps illustrated below

Choose Yes here to register the DataKeeper Volume resource in Available Storage

Complete the above steps for each of the volumes. Once you are finished, you should see the following in the WSFC UI.

You are now ready to install SQL Server into the cluster.

NOTE – At this point the replicated volume is only accessible on the node that is currently hosting Available Storage. That is expected, so don’t worry!

Install SQL Server on the first node

If you want to script the installation, I have included the example below of a scripted cluster installation of SQL Server 2008 R2 into the first node of cluster. The script to add a node to existing cluster is found further down in the guide.

Of course adjust for your environment.

c:\SQLServerFull\setup.exe /q /ACTION=InstallFailoverCluster /FEATURES=SQL /INSTANCENAME="MSSQLSERVER" /INSTANCEDIR="C:\Program Files\Microsoft SQL Server" /INSTALLSHAREDDIR="C:\Program Files\Microsoft SQL Server" /SQLSVCACCOUNT="contoso\admin" /SQLSVCPASSWORD="xxxxxxxxx" /AGTSVCACCOUNT="contoso\admin" /AGTSVCPASSWORD="xxxxxxxxx" /SQLDOMAINGROUP="contoso\SQLAdmins" /AGTDOMAINGROUP="contoso\SQLAdmins" /SQLCOLLATION="SQL_Latin1_General_CP1_CI_AS" /FAILOVERCLUSTERGROUP="SQL Server 2008 R2 Group" /FAILOVERCLUSTERDISKS="DataKeeper Volume E" "DataKeeper Volume F" /FAILOVERCLUSTERIPADDRESSES="IPv4;10.0.0.101;Cluster Network 1;255.255.255.0" /FAILOVERCLUSTERNETWORKNAME="SQL2008Cluster" /SQLSYSADMINACCOUNTS="contoso\admin" /SQLUSERDBLOGDIR="E:\MSSQL10.MSSQLSERVER\MSSQL\Log" /SQLTEMPDBLOGDIR="F:\MSSQL10.MSSQLSERVER\MSSQL\Log" /INSTALLSQLDATADIR="F:\MSSQL10.MSSQLSERVER\MSSQLSERVER" /IAcceptSQLServerLicenseTerms

If you prefer to use the GUI, just follow along with the screenshots below.

On the first node, run the SQL Server setup.

Choose New SQL Server Failover Cluster Installation and follow the steps as illustrated.

Choose only the options you need.

Please note, this document assumes you are using the Default instance of SQL Server. If you use a Named Instance you need to make sure you lock down the port that it listens on, and use that port later on when you configure the load balancer. You also will need to create a load balancer rule for the SQL Server Browser Service (UDP 1434) in order to connect to a Named Instance. Neither of those two requirements are covered in this guide, but if you require a Named Instance it will work if you do those two additional steps.

Here you will need to specify an unused IP address

Go to the Data Directories tab and relocate data and log files. At the end of this guide we talk about relocating tempdb to a non-mirrored DataKeeper Volume for optimal performance. For now, just keep it on one of the clustered disks.

Install SQL Server on the second node

Below is an example of the command you can run to add an additional SQL Server 2008 R2 node into an existing cluster.

c:\SQLServerFull\setup.exe /q /ACTION=AddNode /INSTANCENAME="MSSQLSERVER" /SQLSVCACCOUNT="contoso\admin" /SQLSVCPASSWORD="xxxxxxxxx" /AGTSVCACCOUNT="contoso\admin" /AGTSVCPASSWORD="xxxxxxxx" /IAcceptSQLServerLicenseTerms

If you prefer using the GUI, follow along with the following screenshots.

Run the SQL Server setup again on the second node and choose Add node to a SQL Server Failover Cluster.

Congratulations, you are almost done! However, due to Azure’s lack of support for gratuitous ARP, we will need to configure an Internal Load Balancer (ILB) to assist with client redirection as shown in the following steps.

Update the SQL Cluster IP Address

In order for the ILB to function properly, you must run run the following command from one of the cluster nodes. It SQL Cluster IP enables the SQL Cluster IP address to respond to the ILB health probe while also setting the subnet mask to 255.255.255.255 in order to avoid IP address conflicts with the health probe.

cluster res <IPResourceName> /priv enabledhcp=0 address=<ILBIP> probeport=59999  subnetmask=255.255.255.255

NOTE – I don’t know if it is a fluke, but on occasion I have run this command and it looks like it runs, but it doesn’t complete the job and I have to run it again. The way I can tell if it worked is by looking at the Subnet Mask of the SQL Server IP Resource, if it is not 255.255.255.255 then you know it didn’t run successfully.  It may simple be a GUI refresh issue, so you can also try restarting the cluster GUI to verify the subnet mask was updated.

After it runs successfully, take the resource offline and bring it back online for the changes to take effect.

Create the Load Balancer

The final step is to create the load balancer. In this case we are assuming you are running the Default Instance of SQL Server, listening on port 1433.

The Private IP Address you define when you Create the load balancer will be the exact same address your SQL Server FCI uses.

Add just the two SQL Server instances to the backend pool. Do NOT add the FSW to the backend pool.

In this load balancing rule you must enable Floating IP

Validate the Cluster

Before you continue, run cluster validation one more time. The Cluster Validation report should return just the same network and storage warnings that it did the first time you ran it. Assuming there are no new errors or warnings, your cluster is configured correctly.

Test the Cluster

The most simple test is to open SQL Server Management Studio on the passive node and connect to the cluster. If you are able to connect, congratulations, you did everything correct! If you can’t connect don’t fear, you wouldn’t be the first person to make a mistake. I wrote a blog article to help troubleshoot the issue. Managing the cluster is exactly the same as managing a traditional shared storage cluster. Everything is controlled through Failover Cluster Manager.

Optional – Relocate Tempdb

For optimal performance it would be advisable to move tempdb to the local, non replicated, SSD. However, SQL Server 2008 R2 requires tempdb to be on a clustered disk. SIOS has a solution called a Non-Mirrored Volume Resource which addresses this issue. It would be advisable to create a non-mirrored volume resource of the local SSD drive and move tempdb there. However, the local SSD drive is non-persistent, so you must take care to ensure the folder holding tempdb and the permissions on that folder are recreated each time the server reboots.

After you create the Non-Mirrored Volume Resource of the local SSD, follow the steps in this article to relocate tempdb. The startup script described in that article must be added to each cluster node.

For More Information

As always, if you have questions or comments you can leave them in the comment section below or reach me on Twitter @daveberm

STEP-BY-STEP: HOW TO CONFIGURE A SQL SERVER 2008 R2 FAILOVER CLUSTER INSTANCE ON WINDOWS SERVER 2008 R2 IN AZURE OR AZURE STACK

Achieving SQL Server HA/DR with a mix of Always On Availability Groups and SANless SQL Server Failover Cluster Instances

Introduction

The topic of mixing SQL Server Failover Cluster Instances (FCI) with Always On Availability Groups (AG) is pretty well documented. However, most of the available documentation documents configurations that assume the SQL Server FCI portion of the solution utilizes shared storage. What if I want to build a SANless SQL Server FCI using Storage Spaces Direct (S2D), can I still add a SQL Server AG to the mix? Unfortunately, the answer to this question is no. As of today, this combination of S2D based SQL Server FCI and Always On AG is not supported. I previously blogged about this S2D limitation here.

However, the good news is you CAN build a SANless SQL Server FCI with SIOS DataKeeper and still leverage Always On AG for things like readable secondaries. You still have to abide by the same rules that apply when mixing traditional SAN based SQL Server FCI and Always On AGs, but other than that it is exactly the same….mostly.

DataKeeper Synchronous replication is commonly used between nodes in the same data center or cloud region, but you may want to replicate asynchronously to an additional node in a different region for disaster recovery. In this case, if you ever do have to bring the DR node online after an unexpected failure, you will have to scrap the Always On AG configurations and reconfigure them. This requirement is very similar to to what Microsoft published here in regards to restoring asynchronous snapshots of SQL Server Always On AGs running inside VMs.

Availability Groups

Essentially, a SANLess SQL Server FCI w/DataKeeper looks like a single instance of SQL Server as far as the Always On Availability Group Wizard is concerned. The configuration of the Always On AG is exactly the same as if you were creating just an Always On AG between two Standalone (non-clustered) SQL Server instances.

The real confusion arise in the fact that in this configuration all the servers reside in the same failover cluster, but the SQL Server FCI is only configured to run only on the cluster nodes where SQL Server was installed as a Clustered SQL Server Instance. The other nodes are in the same cluster, but SQL is installed on those nodes as a Standalone SQL Server Instance, not a Clustered Instance. It’s a bit confusing, but what is happening is that Always On AG’s leverage the WSFC quorum model and listeners, so all the AG Replicas need to reside in the same WSFC, even though they typically do not run clustered instances of SQL Server. If you are completely confused that is okay, most people are confused when they first try to wrap their head around this hybrid configuration.

The real benefit in a configuration like this is that a SQL Server FCI can be a better and more cost effective (more on this later*) HA solution than Always On AG in many circumstances, but it lacks the ability to offer a readable secondary replica. Adding an Always On AG readable secondary replica becomes a viable option to address this need. And using SIOS DataKeeper eliminates the need for a SAN for the SQL Server FCI, which opens up the possibility of configuring SQL Server FCIs where nodes reside in different data center, which also means support for SQL Server FCI’s that span Availability Zones in both Azure and AWS.

Please note that pictured below is just one possible configuration. Multiple FCI cluster nodes, multiple AGs and multiple Replicas are all supported. You are only limited by the limits imposed by your version of SQL Server.

This article seems to document the setup steps pretty well. Of course, instead of shared storage for the SQL FCI, you will use SIOS DataKeeper to build the FCI as I document here.

Image result for SQL Server FCI with Availability Groups

Basic Availability Groups

As of SQL Server 2016 a scaled down “Basic Availability Groups” became available in SQL Server Standard Edition, making this configuration possible even in SQL Server Standard Edition. Basic AGs are limited to a single database per Availability Group, a Single Replica (2-nodes). However, they do not support a readable secondary replica so their use cases in this hybrid configuration are very limited.

Distributed Availability Groups

Distributed AGs were introduced in SQL Server 2016 are also supported in this hybrid configuration. Distributed AGs are very similar to regular AGs, but the Replicas do not need to reside in the same cluster, or even in the same Windows Domain. Microsoft documents the the main use cases of Distributed Availability Groups as follows:

  • Disaster recovery and easier multi-site configurations
  • Migration to new hardware or configurations, which might include using new hardware or changing the underlying operating systems
  • Increasing the number of readable replicas beyond eight in a single availability group by spanning multiple availability groups
Image result for distributed availability groups

Summary

If you like the idea of SQL Server FCIs for high availability, but want the flexibility of read-only secondary replicas, this hybrid solution might just be the thing you are looking for. Traditional SAN baseds SQL Server FCIs, and even Storage Spaces Direct (S2D) based FCIs, limit you to a single data center. SIOS DataKeeper frees you from the limits of your SAN and enables configurations such as SQL Server FCI that span Availability Zones or Cloud Regions. It also eliminates the reliance on the SAN, allowing you to leverage locally attached high speed storage devices without giving up your SQL Server FCI.

* How to Save Money

Earlier I promised I would tell you how to save money by doing this all with SQL Server Standard Edition. If you can live with readable replicas that are point in time based snapshots, you can skip Always On AGs completely and just use the SIOS DataKeeper target side snapshot feature to periodically take an application consistent snapshot of the volumes on the target server without impacting ongoing replication or availability. Here’s how…

http://discover.us.sios.com/rs/siostechnology/images/10-Ways-Save-AlwaysOn-vs-Failover-Clustering.pdf

Create a 2-node SQL Server FCI with SQL Server Standard Edition and save a boatload of money on SQL licenses, but yet still replicate the data to a 3rd node outside the cluster for reporting or DR purposes. If you take a snapshot of the volumes on this third server these snapshots are read-right accessible, so you can mount those databases from a standalone instance of SQL Server to run month end reports, copy to archives, or you might even want to use those snapshot to quickly and easily update your QA and Test/Dev environments with the latest SQL data.

I hope you found this helpful and informative. As always, if you have questions, add them here or reach me on Twitter @daveberm

Achieving SQL Server HA/DR with a mix of Always On Availability Groups and SANless SQL Server Failover Cluster Instances

Configure SQL Server Failover Cluster Instance on Azure Virtual Machines with MSDTC #SQL #Azure #MSDTC

If you have been following my blog, you probably know that I write a lot of step-by-step guides for building SQL Server Failover Cluster Instances (FCI) on Azure, from SQL Server 2008 through the lastest. Here are some links to get you started, but really there is very little difference in the configuration between the different versions of Windows and SQL Server, so I think you will be able to figure it out regardless of what versions you use.

STEP-BY-STEP: HOW TO CONFIGURE A SQL SERVER FAILOVER CLUSTER INSTANCE (FCI) IN MICROSOFT AZURE IAAS #SQLSERVER #AZURE #SANLESS

STEP-BY-STEP: HOW TO CONFIGURE A SQL SERVER 2008 R2 FAILOVER CLUSTER INSTANCE IN AZURE

What I have not addressed is what to do about MSDTC. Microsoft addressed that in this article posted here.

https://blogs.msdn.microsoft.com/sql_pfe_blog/2018/07/05/configure-sql-server-failover-cluster-instance-on-azure-virtual-machines-with-msdtc

However, that article/video only addresses SQL Server 2016 and later. The good news is that most of that guidance can be applied to SQL Server 2008/2012/2014. Until I have time to do a proper step-by-step guide I wanted to jot down some basic notes, more as a reminder to myself, but you might find this information useful as well in the meantime.

The steps below assume you have already created a SQL Server FCI in Azure and clustered the DTC resource. Reference the guides above for the details on those steps. The steps below really just detail the load balancer configuration required in Azure to make this work.

Create Load Balancer for MSDTC

The MSDTC resource will require its own load balancer. Instead of creating a new load balancer, we will add a new frontend to the load balancer that should already be configured for the SQL Server FCI. Of course this frontend IP address should match the cluster IP address associated with the clustered MSDTC resource.

For the backend pool just reuse the existing pool that you created that contains the SQL cluster nodes.

You will need to create a new health probe dedicated to the MSDTC resource. The port you use has to be different than the one you used for the SQL resource, so don’t use 59999. Instead maybe use something like 49999.

The final step is to create the load balancing rule for MSDTC. Create a new rule and reference the MSDTC frontend that we just created and the existing backend. Next we need to create a new load balancing rule. Since MSDTC uses ephemeral ports, which is a big range of ports, when you create the rule you have to select the box that says “HA Ports”. And finally make sure Direct Server Return is enabled.

Update MSDTC Cluster IP Resource

Just like our SQL Server Cluster IP address, we need to run a Powershell command that will for the MSDTC cluster IP resource to respond to the health probe we just created that probes port 49999. It also sets the subnet mask of that MSDTC cluster IP address to 255.255.255.255 to avoid IP address conflicts with the load balancer frontend we setup that shares the same address.

# Define variables $ClusterNetworkName = “”  
# the cluster network name (Use Get-ClusterNetwork on Windows Server 2012 of higher to find the name of the MSDTC resource) $IPResourceName = “”  
# the IP Address resource name of the MSDTC resource  $ILBIP = “”  
# the IP Address of the Internal Load Balancer (ILB) and MSDTC resource 
Import-Module FailoverClusters 
# If you are using Windows Server 2012 or higher: 
Get-ClusterResource $IPResourceName | Set-ClusterParameter -Multiple @{Address=$ILBIP;ProbePort=49999;SubnetMask="255.255.255.255";Network=$ClusterNetworkName;EnableDhcp=0} 
# If you are using Windows Server 2008 R2 use this:  
#cluster res $IPResourceName /priv enabledhcp=0 address=$ILBIP probeport=59999  subnetmask=255.255.255.255

Confirm it is working!

You can use DTCPing or go into Component Services and look under Computers>My Computers>Distributed Transaction Coordinator where you should see a local DTC and a clustered DTC. Any distributed transactions should appear in the clustered DTC, not the local DTC. Check out this video for an example of how to create a distributed transaction for testing.

Next Steps

This is a quick and dirty guide, but for the experienced user it should get your MSDTC resource up and running in Azure. I’ll be publishing a detailed step-by-step guide in the near future. In the meantime, if you get stuck don’t hesitate to reach out to me on Twitter @daveberm

Configure SQL Server Failover Cluster Instance on Azure Virtual Machines with MSDTC #SQL #Azure #MSDTC

Step-by-Step: How to configure a SQL Server 2008 R2 Failover Cluster Instance in Azure

Introduction

If you are reading this article you probably are still using SQL Server 2008/2008 R2 and want to take advantage of the extended security updates that Microsoft is offering if you move your SQL Server 2008/2008 R2 into Azure. I previously wrote about this topic in this blog post.

You may be wondering how to make sure your SQL Server instance remains highly available once you make the move to Azure. Today, most people have business critical SQL Server 2008/2008 R2 configured as a clustered instance (SQL Server FCI) in their data center. When looking at Azure you have probably come to the realization that due to the lack of shared storage it might seem that you can’t bring your SQL Server FCI to the Azure cloud. However, that is not the case thanks to SIOS DataKeeper.

SIOS DataKeeper enables you to build a SQL Server FCI in Azure, AWS, Google Cloud, or anywhere else where shared storage is not available or where you wish to configure multi-site clusters where shared storage doesn’t make sense. DataKeeper has been enabling SANless clusters for WIndows and Linux since 1999. Microsoft documents the use of SIOS DataKeeper for SQL Server FCI in their documentation: High availability and disaster recovery for SQL Server in Azure Virtual Machines.

I’ve written about SQL Server FCI’s running in Azure before, but I never published a Step-by-Step Guide specific to SQL Server 2008/2008 R2. The good news is that it works just as great with SQL 2008/2008 R2 as it does with SQL 2012/2014/2016/2017 and the soon to be released 2019. Also, regardless of the version of Windows Server (2008/2012/2016/2019) or SQL Server (2008/2012/2014/2016/2017) the configuration process is similar enough that this guide should be sufficient enough to get you through any configurations.

If your flavor of SQL or Windows is not covered in any of my guides, don’t be afraid to jump in and build a SQL Server FCI and reference this guide, I think you will figure out any differences and if you ever get stuck just reach out to me on Twitter @daveberm and I’ll be glad to give you a hand.

This guide uses SQL Server 2008 R2 with Windows Server 2012 R2. As of the time of this writing I did not see an Azure Marketplace image of SQL 2008 R2 on Windows Server 2012 R2, so I had to download and install SQL 2008 R2 manually. Personally I prefer this combination, but if you need to use Windows Server 2008 R2 or Windows 212 that is fine. If you use Windows Server 2008 R2 don’t forget to install the kb3125574 Convenience Rollup Update for Windows Server 2008 R2 SP1. Or if you are stuck with Server 2012 (not R2) you need the Hotfix in kb2854082.

Don’t be fooled by this article that says you must install kb2854082 on your SQL Server 2008 R2 instances. If you start searching for that update for Windows Server 2008 R2 you will find that only the version for Server 2012 is available. That particular hotfix for Server 2008 R2 is instead included in the rollup Convenience Rollup Update for Windows Server 2008 R2 SP1.

Provision Azure Instances

I’m not going to go into great detail here with a bunch of screenshots, especially since the Azure Portal UI tends to change pretty frequently, so any screenshots I take will get stale pretty quickly. Instead, I will just cover the important topics that you should be aware of.

Fault Domains or Availability Zones?

In order to ensure your SQL Server instances are highly available, you have to make sure your cluster nodes reside in different Fault Domains (FD) or in different Availability Zones (AZ). Not only do your instances need to reside in different FDs or AZs, but your File Share Witness (see below) also needs to reside in a FD or AZ that is different than that one your cluster nodes reside in.

Here is my take on it. AZs are the newest Azure feature, but they are only supported in a handful of regions so far. AZs give you a higher SLA (99.99%) then FDs (99.95%), and protect you against the kind of cloud outages I describe in my post Azure Outage Post-Mortem. If you can deploy in a region that supports AZs then I recommend you use AZs.

In this guide I used AZs which you will see when you get to the section on configuring the load balancer. However, if you use FDs everything will be exactly the same, except the load balancer configuration will reference Availability Sets rather than Availability Zones.

What is a File Share Witness you ask?

Without going into great detail, Windows Server Failover Clustering (WSFC) requires you configure a “Witness” to ensure failover behaves properly. WSFC supports three kinds of witnesses: Disk, File Share, Cloud. Since we are in Azure a Disk Witness is not possible. Cloud Witness is only available with Windows Server 2016 and later, so that leaves us with a File Share Witness. If you want to learn more about cluster quorums check out my post on the Microsoft Press Blog, From the MVPs: Understanding the Windows Server Failover Cluster Quorum in Windows Server 2012 R2

Add storage to your SQL Server instances

As you provision your SQL Server instances you will want to add additional disks to each instance. Minimally you will need one disk for the SQL Data and Log file, one disk for Tempdb. Whether or not you should have a seperate disk for log and data files is somewhat debated when running in the cloud. On the back end the storage all comes from the same place and your instance size limits your total IOPS. In my opinion there really isn’t any value in separating your log and data files since you cannot ensure that they are running on two physical sets of disks. I’ll leave that for you to decide, but I put log and data all on the same volume.

Normally a SQL Server 2008 R2 FCI would require you to put tempdb on a clustered disk. However, SIOS DataKeeper has this really nifty feature called a DataKeeper Non-Mirrored Volume Resource. This guide does not cover moving tempdb to this non-mirrored volume resource, but for optimal performance you should do this. There really is no good reason to replicate tempdb since it is recreated upon failover anyway.

As far as the storage is concerned you can use any storage type, but certainly use Managed Disks whenever possible. Make sure each node in the cluster has the identical storage configuration. Once you launch the instances you will want to attach these disks and format them NTFS. Make sure each instance uses the same drive letters.

Networking

It’s not a hard requirement, but if at all possible use an instance size that supports accelerated networking. Also, make sure you edit the network interface in the Azure portal so that your instances use a static IP address. For clustering to work properly you want to make sure you update the settings for the DNS server so that it points to your Windows AD/DNS server and not just some public DNS server.

Security

By default, the communications between nodes in the same virtual network are wide open, but if you have locked down your Azure Security Group you will need to know what ports must be open between the cluster nodes and adjust your security group. In my experience, almost all the issues you will encounter when building a cluster in Azure are either caused by blocked ports.

DataKeeper has some some ports that are required to be open between the clustered instance. Those ports are as follows:
UDP: 137, 138
TCP: 139, 445, 9999, plus ports in the 10000 to 10025 range

Failover cluster has its own set of port requirements that I won’t even attempt to document here. This article seems to have that covered. http://dsfnet.blogspot.com/2013/04/windows-server-clustering-sql-server.html

In addition, the Load Balancer described later will use a probe port that must allow inbound traffic on each node. The port that is commonly used and described in this guide is 59999.

And finally if you want your clients to be able to reach your SQL Server instance you want to make sure your SQL Server port is open, which by default is 1433.

Remember, these ports can be blocked by the Windows Firewall or Azure Security Groups, so to be sure to check both to ensure they are accessible.

Join the Domain

A requirement for SQL Server 2008 R2 FCI is that the instances must reside in the same Windows Server Domain. So if you have not done so, make sure you have joined the instances to your Windows domain

Local Service Account

When you install DataKeeper it will ask you to provide a service account. You must create a domain user account and then add that user account to the Local Administrators Group on each node. When asked during the DataKeeper installation, specify that account as the DataKeeper service account. Note – Don’t install DataKeeper just yet!

Domain Global Security Groups

When you install SQL 2008 R2 you will be asked to specify two Global Domain Security Groups. You might want to look ahead at the SQL install instructions and create those groups now. You will also want to create a domain user account and place them in each of these security accounts. You will specify this account as part of the SQL Server Cluster installation.

Other Pre-Requisites

You must enable both Failover Clustering and .Net 3.5 on each instance of the two cluster instances. When you enable Failover Clustering, also be sure to enable the optional “Failover Cluster Automation Server” as it is required for a SQL Server 2008 R2 cluster in Windows Server 2012 R2.

Create the Cluster and DataKeeper Volume Resources

We are now ready to start building the cluster. The first step is to create the base cluster. Because of the way Azure handles DHCP, we MUST create the cluster using Powershell and not the Cluster UI. We use Powershell because it will let us specify a static IP address as part of the creation process. If we used the UI it would see that the VMs use DHCP and it will automatically assign a duplicate IP address, so we we want to avoid that situation by using Powershell as shown below.

New-Cluster -Name cluster1 -Node sql1,sql2 -StaticAddress 10.0.0.100 -NoStorage

After the cluster creates, run Test-Cluster. This is required before SQL Server will install.

Test-Cluster

You will get warnings about Storage and Networking, but you can ignore those as they are expected in a SANless cluster in Azure. If there are any other warnings or errors you must address those before moving on.

After the cluster is created you will need to add the File Share Witness. On the third server we specified as the file share witness, create a file share and give Read/Write permissions to the cluster computer object we just created above. In this case $Cluster1 will be the name of the computer object that needs Read/Write permissions at both the share and NTFS security level.

Once the share is created, you can use the Configure Cluster Quorum Wizard as shown below to configure the File Share Witness.

Install DataKeeper

It is important to wait until the basic cluster is created before we install DataKeeper since the DataKeeper installation registers the DataKeeper Volume Resource type in failover clustering. If you jumped the gun and installed DataKeeper already that is okay. Simply run the setup again and choose Repair Installation.

The screenshots below walk you through a basic installation. Start by running the DataKeeper Setup.

The account you specify below must be a domain account and must be part of the Local Administrators group on each of the cluster nodes.

When presented with the SIOS License Key manager you can browse out to your temporary key, or if you have a permanent key you can copy the System Host ID and use that to request your permanent license. If you ever need to refresh a key the SIOS License Key Manager is a program that will be installed that you can run separately to add a new key.

Create DataKeeper Volume Resource

Once DataKeeper is installed on each node you are ready to create your first DataKeeper Volume Resource. The first step is to open the DataKeeper UI and connect to each of the cluster nodes.

If everything is done correctly the Server Overview Report should look something like this.

You can now create your first Job as shown below.

After you choose a Source and Target you are presented with the following options. For a local target in the same region the only thing you need to select is Synchronous.

Choose Yes and auto-register this volume as a cluster resource.

Once you complete this process open up the Failover Cluster Manager and look in Disk. You should see the DataKeeper Volume resource in Available Storage. At this point WSFC treats this as if it were a normal cluster disk resource.

Slipstream SP3 onto SQL 2008 R2 install media

SQL Server 2008 R2 is only supported on Windows Server 2012 R2 with SQL Server SP2 or later. Unfortunately, Microsoft never released a SQL Server 2008 R2 installation media that that includes SP2 or SP3. Instead, you must slipstream the service pack onto the installation media BEFORE you do the installation. If you try to do the installation with the standard SQL Server 2008 R2 media you will run into all kinds of problems. I don’t remember the exact errors you will see, but I do recall they didn’t really point to the exact problem and you will waste a lot of time trying to figure out what went wrong.

As of the date of this writing, Microsoft does not have a Windows Server 2012 R2 with SQL Server 2008 R2 offering in the Azure Marketplace, so you will be bringing your own SQL license if you want to run SQL 2008 R2 on Windows Server 2012 R2 in Azure. If they add that image later, or if you choose to use the SQL 2008 R2 on Windows Server 2008 R2 image you must first uninstall the existing standalone instance of SQL Server before moving forward.

I followed the guidance in Option 1 of this article to slipstream SP3 on onto my SQL 2008 R2 installation media. You will of course have to adjust a few things as this article references SP2 instead of SP3. Make sure you slipstream SP3 on the installation media we will use for both nodes of the cluster. Once that is done, continue to the next step.

Install SQL Server on the First Node

Using the SQL Server 2008 R2 media with SP3 slipstreamed, run setup and install the first node of the cluster as shown below.

If you use anything other than the Default instance of SQL Server you will have some additional steps not covered in this guide. The biggest difference is you must lock down the port that SQL Server uses since by default a named instance of SQL Server does NOT use 1433. Once you lock down the port you also need to specify that port instead of 1433 whenever we reference port 1433 in this guide, including the firewall setting and the Load Balancer settings.

Here make sure to specify a new IP address that is not in use. This is the same IP address we will use later when we configure the Internal Load Balancer later.

As I mentioned earlier, SQL Server 2008 R2 utilizes AD Security Groups. If you have not already created them, go ahead and create them now as show below before you continue to the next step in the SQL install

Specify the Security Groups you created earlier.

Make sure the service accounts you specify are a member of the associated Security Group.

Specify your SQL Server administrators here.

If everything goes well you are now ready to install SQL Server on the second node of the cluster.

Install SQL Server on the Second Node

One the second node, run the SQL Server 2008 R2 with SP3 install and select Add Node to a SQL Server FCI.

Proceed with the installation as shown in the following screenshots.

Assuming everything went well, you should now have a two node SQL Server 2008 R2 cluster configured that looks something like the following.

However, you probably will notice that you can only connect to the SQL Server instance from the active cluster node. The problem is that Azure does not support gratuitous ARP, so your clients cannot connect directly to the Cluster IP Address. Instead, the clients must connect to an Azure Load Balancer, which will redirect the connection to the active node. To make this work there are two steps: Create the Load Balancer and Fix the SQL Server Cluster IP to respond to the Load Balancer Probe and use a 255.255.255.255 Subnet mask. Those steps are described below.

Create the Azure Load Balancer

I’m going to assume your clients can communicate directly to the internal IP address of the SQL cluster so we will create an Internal Load Balancer (ILB) in this guide. If you need to expose your SQL Instance on the public internet you can use a Public Load Balancer instead.

In the Azure portal create a new Load Balancer following the screenshots as shown below. The Azure portal UI changes rapidly, but these screenshots should give you enough information to do what you need to do. I will call out important settings as we go along.

Here we create the ILB. The important thing to note on this screen is you must select “Static IP address assignment” and specify the same IP address that we used during the SQL Cluster installation.

Since I used Availability Zones I see Zone Redundant as an option. If you used Availability Sets your experience will be slightly different.

In the Backend pool be sure to select the two SQL Server instances. You DO NOT want to add your File Share Witness in the pool.

Here we configure the Health Probe. Most Azure documentation has us using port 59999, so we will stick with that port for our configuration.

Here we will add a load balancing rule. In our case we want to redirect all SQL Server traffic to TCP port 1433 of the active node. It is also important that you select Floating IP (Direct Server Return) as Enabled.

Run Powershell Script to Update SQL Client Access Point

Now we must run a Powershell script on one of the cluster nodes to allow the Load Balancer Probe to detect which node is active. The script also sets the Subnet Mask of the SQL Cluster IP Address to 255.255.255.255.255 so that it avoids IP address conflicts with the Load Balancer we just created.

# Define variables
$ClusterNetworkName = “” 
# the cluster network name (Use Get-ClusterNetwork on Windows Server 2012 of higher to find the name)
$IPResourceName = “” 
# the IP Address resource name 
$ILBIP = “” 
# the IP Address of the Internal Load Balancer (ILB) and SQL Cluster
Import-Module FailoverClusters
# If you are using Windows Server 2012 or higher:
Get-ClusterResource $IPResourceName | Set-ClusterParameter -Multiple @{Address=$ILBIP;ProbePort=59999;SubnetMask="255.255.255.255";Network=$ClusterNetworkName;EnableDhcp=0}
# If you are using Windows Server 2008 R2 use this: 
#cluster res $IPResourceName /priv enabledhcp=0 address=$ILBIP probeport=59999  subnetmask=255.255.255.255

This is what the output will look like if run correctly.

You probably notice that the end of that script has a commented line of code to use if you are running on Windows Server 2008 R2. If you are running Windows Server 2008 R2 make sure you run the code specific for Windows Server 2008 R2 at a Command prompt, it is not Powershell.

Next Steps

If you get to this point and you still cannot connect to the cluster remotely you wouldn’t be the first person. There are a lot of things that can go wrong in terms of security, load balancer, SQL ports, etc. I wrote this guide to help troubleshoot connection issues.

In fact, in this very installation I ran into some strange issues in terms of my SQL Server TCP/IP Properties in SQL Server Configuration Manager. When I looked at the properties I did not see the SQL Server Cluster IP address as one of the addresses it was listening on, so I had to add it manually. I’m not sure if that was an anomaly, but it certainly was an issue I had to resolve before I could connect to the cluster from a remote client.

As I mentioned earlier, one other improvement you can make to this installation is to use a DataKeeper Non-Mirrored Volume Resource for TempDB. If you set that up please be aware of the following two configuration issues people commonly run into.

The first issue is if you move tempdb to a folder on the 1st node, you must be sure to create the exact same folder structure on the second node. If you don’t do that when you try to failover SQL Server will fail to come online since it can’t create TempDB

The second issue occurs anytime you add another DataKeeper Volume Resource to a SQL Cluster after the cluster is created. You must go into the properties of the SQL Server cluster resource and make it dependent on the new DataKeeper Volume resource you added. This is true for the TempDB volume and any other volumes you may decide to add after the cluster is created.

If you have any questions about this configuration or any other cluster configurations please feel free to reach out to me on Twitter @DaveBerm.

Step-by-Step: How to configure a SQL Server 2008 R2 Failover Cluster Instance in Azure

Step-by-Step: Configuring a File Server Cluster in Azure that Spans Availability Zones

In this post we will detail the specific steps required to deploy a 2-node File Server Failover Cluster that spans the new Availability Zones a single region of Azure. I will assume you are familiar with basic Azure concepts as well as basic Failover Cluster concepts and will focus this article on what is unique about deploying a File Server Failover Cluster in Azure across Availability Zones.  If your Azure region doesn’t support Availability Zones yet you will have to use Fault Domains instead as described in an earlier post.

With DataKeeper Cluster Edition you are able to take the locally attached Managed Disks, whether it is Premium or Standard Disks, and replicate those disks either synchronously, asynchronously or a mix or both, between two or more cluster nodes. In addition, a DataKeeper Volume resource is registered in Windows Server Failover Clustering which takes the place of a Physical Disk resource. Instead of controlling SCSI-3 reservations like a Physical Disk Resource, the DataKeeper Volume controls the mirror direction, ensuring the active node is always the source of the mirror. As far as Failover Clustering is concerned, it looks, feels and smells like a Physical Disk and is used the same way Physical Disk Resource would be used.

Pre-requisites

  • You have used the Azure Portal before and are comfortable deploying virtual machines in Azure IaaS.
  • Have obtained a license or eval license of SIOS DataKeeper

Deploying a File Server Failover Cluster Instance using the Azure Portal

To build a 2-node File Server Failover Cluster Instance in Azure, we are going to assume you have a basic Virtual Network based on Azure Resource Manager and you have at least one virtual machine up and running and configured as a Domain Controller. Once you have a Virtual Network and a Domain configured, you are going to provision two new virtual machines which will act as the two nodes in our cluster.

Our environment will look like this:

DC1 – Our Domain Controller and File Share Witness
SQL1 and SQL2 – The two nodes of our File Server Cluster. Don’t let the names confuse you, we are building a File Server Cluster in this guide. In my next post I will demonstrate a SQL Server cluster configuration.

Provisioning the two cluster nodes

Using the Azure Portal, we will provision both SQL1 and SQL2 exactly the same way.  There are numerous options to choose from including instance size, storage options, etc. This guide is not meant to be an exhaustive guide to deploying Servers in Azure as there are some really good resources out there and more published every day. However, there are a few key things to keep in mind when creating your instances, especially in a clustered environment.

Availability Zones – It is important that both SQL1, SQL2 reside in different Availability Zones. For the sake of this guide we will assume you are using Windows 2016 and will use a Cloud Witness for the Cluster Quorum. If you use Windows 2012 R2 or Windows Server 2008 R2 instead of Windows 2016 you will instead need to configure a File Share Witness in the 3rd Availability Zone as Cloud Witness was not introduced until Windows Server 2016.

By putting the cluster nodes in different Availability Zones we are ensuring that each cluster node resides in a different Azure datacenter in the same region. Leveraging Availability Zones rather than the older Fault Domains isolates you from the types of outages that occured just a few weeks ago that brought down the entire South Central region for multiple days.

Availability Zones
Be sure to add each cluster node to a different Availability Zone. If you leverage a File Share Witness it should reside in the 3rd Availability Zone.

Static IP Address

Once each VM is provisioned, you will want to go into the setting and change the settings so that the IP address is Static. We do not want the IP address of our cluster nodes to change.

Static IP
Make sure each cluster node uses a static IP

Storage

As far as Storage is concerned, you will want to consult Performance best practices for SQL Server in Azure Virtual Machines. In any case, you will minimally need to add at least one additional Managed Disk to each of your cluster nodes. DataKeeper can use Basic Disk, Premium Storage or even multiple disks striped together in a local Storage Space. If you do want to use a local Storage Space just be aware that you should create the Storage Space BEFORE you do any cluster configuration due to a known issue with Failover Clustering and local Storage Spaces. All disks should be formatted NTFS.

Create the Cluster

Assuming both cluster nodes (SQL1 and SQL2) have been provisioned as described above and added to your existing domain, we are ready to create the cluster. Before we create the cluster, there are a few Features that need to be enabled. These features are .Net Framework 3.5 and Failover Clustering. These features need to be enabled on both cluster nodes. You will also need to enable the FIle Server Role.

6
Enable both .Net Framework 3.5 and Failover Clustering features and the File Server on both cluster nodes

Once that role and those features have been enabled, you are ready to build your cluster. Most of the steps I’m about to show you can be performed both via PowerShell and the GUI. However, I’m going to recommend that for this very first step you use PowerShell to create your cluster. If you choose to use the Failover Cluster Manager GUI to create the cluster you will find that you wind up with the cluster being issued a duplicate IP address.

Without going into great detail, what you will find is that Azure VMs have to use DHCP. By specifying a “Static IP” when we create the VM in the Azure portal all we did was create sort of a DHCP reservation. It is not exactly a DHCP reservation because a true DHCP reservation would remove that IP address from the DHCP pool. Instead, this specifying a Static IP in the Azure portal simply means that if that IP address is still available when the VM requests it, Azure will issue that IP to it. However, if your VM is offline and another host comes online in that same subnet it very well could be issued that same IP address.

There is another strange side effect to the way Azure has implemented DHCP. When creating a cluster with the Windows Server Failover Cluster GUI, there is not option to specify a cluster IP address. Instead it relies on DHCP to obtain an address. The strange thing is, DHCP will issue a duplicate IP address, usually the same IP address as the host requesting a new IP address. The cluster install will complete, but you may have some strange errors and you may need to run the Windows Server Failover Cluster GUI from a different node in order to get it to run. Once you get it to run you will need to change the core cluster IP address to an address that is not currently in use on the network.

You can avoid that whole mess by simply creating the cluster via Powershell and specifying the cluster IP address as part of the PowerShell command to create the cluster.

You can create the cluster using the New-Cluster command as follows:

New-Cluster -Name cluster1 -Node sql1,sql2 -StaticAddress 10.0.0.100 -NoStorage

After the cluster creation completes, you will also want to run the cluster validation by running the following command. You should expect to see some warnings about storage and network, but that is expected in Azure and you can ignore those warnings. If any errors are reported you will need to address those before you move on.

Test-Cluster

Create a Quorum Witness

if you are running Windows 2016 or 2019 you will need to create a Cloud Witness for the cluster quorum. If you are running Windows Server 2012 R2 or 2008 R2 you will need to create a File Share Witness. The detailed instruction on witness creation can be found here.

Install DataKeeper

After the cluster is created it is time to install DataKeeper. It is important to install DataKeeper after the initial cluster is created so the custom cluster resource type can be registered with the cluster. If you installed DataKeeper before the cluster is created you will simply need to run the install again and do a repair installation.

8
Install DataKeeper after the cluster is created

During the installation you can take all of the default options.  The service account you use must be a domain account and be in the local administrators group on each node in the cluster.

9
The service account must be a domain account that is in the Local Admins group on each node

Once DataKeeper is installed and licensed on each node you will need to reboot the servers.

Create the DataKeeper Volume Resource

To create the DataKeeper Volume Resource you will need to start the DataKeeper UI and connect to both of the servers.
10Connect to SQL1
11

Connect to SQL2
12

Once you are connected to each server, you are ready to create your DataKeeper Volume. Right click on Jobs and choose “Create Job”
13

Give the Job a name and description.
14

Choose your source server, IP and volume. The IP address is whether the replication traffic will travel.
15

Choose your target server.
16

Choose your options. For our purposes where the two VMs are in the same geographic region we will choose synchronous replication. For longer distance replication you will want to use asynchronous and enable some compression.
17

By clicking yes at the last pop-up you will register a new DataKeeper Volume Resource in Available Storage in Failover Clustering.
18

You will see the new DataKeeper Volume Resource in Available Storage.
19

Create the File Server Cluster Resource

To create the File Server Cluster Resource we will use Powershell once again rather than the Failover Cluster interface. The reason being is that once again because the virtual machines are configured to use DHCP, the GUI based wizard will not prompt us to enter a cluster IP address and instead will issue a duplicate IP address. To avoid this we will use a simple powershell command to create the FIle Server Cluster Resource and specify the IP Address

Add-ClusterFileServerRole -Storage "DataKeeper Volume E" -Name FS2 -StaticAddress 10.0.0.101

Make note of the IP address you specify here. It must be a unique IP address on your network. We will use this same IP address later when we create our Internal Load Balancer.

Create the Internal Load Balancer

Here is where failover clustering in Azure is different than traditional infrastructures. The Azure network stack does not support gratuitous ARPS, so clients cannot connect directly to the cluster IP address. Instead, clients connect to an internal load balancer and are redirected to the active cluster node. What we need to do is create an internal load balancer. This can all be done through the Azure Portal as shown below.

You can use an Public Load Balancer if your client connects over the public internet, but assuming your clients reside in the same vNet, we will create an Internal Load Balancer. The important thing to take note of here is that the Virtual Network is the same as the network where your cluster nodes reside. Also, the Private IP address that you specify will be EXACTLY the same as the address you used to create the File Server Cluster Resource. Also, because we are using Availability Zones we will be creating a Zone Redundant Standard Load Balancer as shown in the picture below.

Load Balancer

After the Internal Load Balancer (ILB) is created, you will need to edit it. The first thing we will do is to add a backend pool. Through this process you will choose the two cluster nodes.

Backend Pools

The next thing we will do is add a Probe. The probe we add will probe Port 59999. This probe determines which node is active in our cluster.
probe

And then finally, we need a load balancing rule to redirect the SMB traffic, TCP port 445 The important thing to notice in the screenshot below is the Direct Server Return is Enabled. Make sure you make that change.

rules

Fix the File Server IP Resource

The final step in the configuration is to run the following PowerShell script on one of your cluster nodes. This will allow the Cluster IP Address to respond to the ILB probes and ensure that there is no IP address conflict between the Cluster IP Address and the ILB. Please take note; you will need to edit this script to fit your environment. The subnet mask is set to 255.255.255.255, this is not a mistake, leave it as is. This creates a host specific route to avoid IP address conflicts with the ILB.

# Define variables
$ClusterNetworkName = “” 
# the cluster network name (Use Get-ClusterNetwork on Windows Server 2012 of higher to find the name)
$IPResourceName = “” 
# the IP Address resource name 
$ILBIP = “” 
# the IP Address of the Internal Load Balancer (ILB)
Import-Module FailoverClusters
# If you are using Windows Server 2012 or higher:
Get-ClusterResource $IPResourceName | Set-ClusterParameter -Multiple @{Address=$ILBIP;ProbePort=59999;SubnetMask="255.255.255.255";Network=$ClusterNetworkName;EnableDhcp=0}
# If you are using Windows Server 2008 R2 use this: 
#cluster res $IPResourceName /priv enabledhcp=0 address=$ILBIP probeport=59999  subnetmask=255.255.255.255

Creating File Shares

You will find that using the File Share Wizard in Failover Cluster Manager does not work. Instead, you will simply create the file shares in Windows Explorer on the active node. Failover clustering automatically picks up those shares and puts them in the cluster.

Note that the”Continuous Availability” option of a file share is not supported in this configuration.

Conclusion

You should now have a functioning File Server Failover Cluster in Azure that spans Availability Zones. If you have ANY problems, please reach out to me on Twitter @daveberm and I will be glad to assist. If you need a DataKeeper evaluation key fill out the form at http://us.sios.com/clustersyourway/cta/14-day-trial and SIOS will send an evaluation key sent out to you.

Step-by-Step: Configuring a File Server Cluster in Azure that Spans Availability Zones

Azure Outage Post-Mortem – Part 1

The first official Post-Mortems are starting to come out of Microsoft in regards to the Azure Outage that happened last week. While this first post-mortem addresses the Azure DevOps outage specifically (previously known as Visual Studio Team Service, or VSTS), it gives us some additional insight into the breadth and depth of the outage, confirms the cause of the outage, and gives us some insight into the challenges Microsoft faced in getting things back online quickly. It also hints at some some features/functionality Microsoft may consider pursuing to handle this situation better in the future.

As I mentioned in my previous article, features such as the new Availability Zones being rolled out in Azure, might have minimized the impact of this outage. In the post-mortem, Microsoft confirms what I previously said.

The primary solution we are pursuing to improve handling datacenter failures is Availability Zones, and we are exploring the feasibility of asynchronous replication.

Until Availability Zones are rolled out across more regions the only disaster recovery options you have are cross-region, hybrid-cloud or even cross-cloud asynchronous replication. Software based #SANless clustering solutions available today will enable such configurations, providing a very robust RTO and RPO, even when replicating great distances.

When you use SaaS/PaaS solutions you are really depending on the Cloud Service Provider (CSPs) to have an iron clad HA/DR solution in place. In this case, it seems as if a pretty significant deficiency was exposed and we can only hope that it leads all CSPs to take a hard look at their SaaS/PaaS offerings and address any HA/DR gaps that might exist. Until then, it is incumbent upon the consumer to understand the risks and do what they can to mitigate the risks of extended outages, or just choose not to use PaaS/SaaS until the risks are addressed.

The post-mortem really gets to the root of the issue…what do you value more, RTO or RPO?

I fundamentally do not want to decide for customers whether or not to accept data loss. I’ve had customers tell me they would take data loss to get a large team productive again quickly, and other customers have told me they do not want any data loss and would wait on recovery for however long that took.

It will be impossible for a CSP to make that decision for a customer. I can’t see a CSP ever deciding to lose customer data, unless the original data is just completely lost and unrecoverable. In that case, a near real-time async replica is about as good as you are going to get in terms of RPO in an unexpected failure.

However, was this outage really unexpected and without warning? Modern satellite imagery and improvements in weather forecasting probably gave fair warning that there was going to be significant weather related events in the area.

With hurricane Florence bearing down on the Southeast US as I write this post, I certainly hope if your data center is in the path of the hurricane you are taking proactive measures to gracefully move your workloads out of the impacted region. The benefit of a proactive disaster recovery vs a reactive disaster recovery are numerous, including no data loss, ample time to address unexpected issues, and managing human resources such that employees can worry about taking care of their families, rather than spending the night at a keyboard trying to put the pieces back together again.

Again, enacting a proactive disaster recovery would be a hard decision for a CSP to make on behalf of all their customers, as planned migrations across regions will incur some amount of downtime. This decision will have to be put in the hands of the customer.

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Hurricane Florence Satellite Image taken from the new GOES-16 Satellite, courtesy of Tropical Tidbits

So what can you do to protect your business critical applications and data? As I discussed in my previous article, cross-region, cross-cloud or hybrid-cloud models with software based #SANless cluster solutions are going to go a long way to address your HA/DR concerns, with an excellent RTO and RPO for cloud based IaaS deployments. Instead of application specific solutions, software based, block level volume replication solutions such SIOS DataKeeper and SIOS Protection Suite replicate all data, providing a data protection solution for both Linux and Windows platforms.

My oldest son just started his undergrad degree in Meteorology at Rutgers University. Can you imagine a day when artificial intelligence (AI) and machine learning (ML) will be used to consume weather related data from NOAA to trigger a planned disaster recovery migration, two days before the storm strikes? I think I just found a perfect topic for his Master’s thesis. Or better yet, have him and his smart friends at the WeatherWatcher LLC get funding for a tech startup that applies AI and ML to weather related data to control proactive disaster recovery events.

I think we are just at the cusp of  IT analytics solutions that apply advanced machine-learning technology to cut the time and effort you need to ensure delivery of your critical application services. SIOS iQ is one of the solutions leading the way in that field.

Batten down the hatches and get ready, Hurricane season is just starting and we are already in for a wild ride. If you would like to discuss your HA/DR strategy reach out to me on Twitter @daveberm.

Azure Outage Post-Mortem – Part 1

Help! I can’t connect to my SQL Server multi-subnet failover cluster

I get that kind of call or email from customers all the time. I have a generic response as follows…

This has everything you need to know.

They don’t go into great detail about what to do if your connection does not support multisubnetfailover=true. If your connection does NOT support that parameter, then set registerallprovidersip to false and cleanup DNS. That procedure is described best here.
I figure I get this question often enough I probably should just flesh out my response a bit, hence the reason for this post.
In general people just aren’t aware of how multi-subnet failover clusters work. Multi-subnet failover clustering support was added in Windows Server 2012 with the addition of the “OR” technology when defining cluster resource dependencies. This allowed people to allow a Cluster Name resource to be dependent upon IP Address x.x.x.x OR IP Address y.y.y.y.
x.x.x.x would be an a cluster IP resource valid in Subnet A and y.y.y.y would be a cluster IP address valid in Subnet B. Only one address will be online at any given time, whichever address was valid for the subnet the resource was currently running on.
Microsoft SQL Server started supporting this concept starting with SQL Server 2012 with both failover cluster instances (FCI) using 3-party SANless clustering solutions like SIOS DataKeeper and SQL Server Always On Availability Groups.
By default if you create a SQL Server multi-subnet failover cluster the cluster should be automatically configured optimally, including setting up the two IP addresses, adding two A records to DNS and setting the registerallprovidersIP to true. However, on the client end you need to tell it that you are connecting to a multi-subnet failover cluster, otherwise the connection won’t be made.

Configuring the client

Configuring the client is done by adding multisubnetfailover=true to the connection string. This Microsoft documentation is a great resource, but if you just search for multisubnetfailover=true you will find a lot of information about that setting.
However, not every application will support adding that to the connection string. If you find yourself in that situation you should ask your application vendor to add support for that or show you how to do it.
However, all is not lost if you find yourself in that situation. You will want to change the behavior of the cluster so that upon failover DNS is update so that the single A record associated with the cluster client access point is updated with the new IP address. This is in lieu of having two A records in DNS, one with each cluster IP address, which is the default behavior in an multi-subnet cluster.
This article reference SharePoint, you can ignore that, the rest of the article is pretty well written to describe the process you should follow.
The highlights of that article are as follows…
Get-ClusterResource “[Network Name]” | Set-ClusterParameter RegisterAllProvidersIP 0
After restarting the cluster-name-object (basically restarting the role) & cleaning up all “A” records manually (clean-up isn’t done automatically) we can see our old A-records are still in DNS so we’ll need to delete those manually.
In addition to those steps I’d advise you to reduce the TTL on the HostRecordTTL as described in this article.
The highlight of that article is as follows.
PS C:\> Get-ClusterResource -Name cluster1FS | Set-ClusterParameter -Name HostRecordTTL -Value 300
With a Value of 300 you could potentially be waiting up to 5 minutes for your clients to reconnect after a failover, or even longer if if have a large Active Directory infrastructure and AD replication takes some time to update all the DNS servers across your infrastructure.
You are going to want to figure out what the optimal TTL is to facilitate quick client reconnections without over burdening your DNS servers with a bunch of DNS Lookup requests.
This type of configuration is common in disaster recovery configurations where your DR site is in a different subnet. It is also very common in HA deployments in AWS because different Availability Zones are in different subnets.
Let me know if you have any questions. You can always reach me on Twitter @daveberm
Help! I can’t connect to my SQL Server multi-subnet failover cluster