Windows Server 2016 – Role Upgrades

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windows-server-2016On the 19th October 2016, Microsoft have clarified what can and cannot be upgraded in-place from Windows Server 2012 and 2012 R2 to Windows Server 2016.

The applications/services which cannot be directly upgraded are:

  • Active Directory Federation Services
  • Hyper-V
  • Print and Fax Services

More details can be found Server Role Upgrades and migration matrix for Windows Server 2016.

Server Role Upgradeable from Windows Server 2012 R2? Upgradeable from Windows Server 2012? Migration Supported? Can migration be completed without downtime?
Active Directory Certificate Services Yes Yes Yes No
Active Directory Domain Services Yes Yes Yes Yes
Active Directory Federation Services No No Yes No (new nodes need to be added to the farm)
Active Directory Lightweight Directory Services Yes Yes Yes Yes
Active Directory Rights Management Services Yes Yes Yes No
DHCP Server Yes Yes Yes Yes
DNS Server Yes Yes Yes No
Failover Cluster Yes with Cluster OS Rolling Upgrade process which includes node Pause-Drain, Evict, upgrade to Windows Server 2016 and rejoin the original cluster. Yes, when the server is removed by the cluster for upgrade and then added to a different cluster. Not while the server is part of a cluster. Yes, when the server is removed by the cluster for upgrade and then added to a different cluster. Yes No for Windows Server 2012 Failover Clusters. Yes for Windows Server 2012 R2 Failover Clusters with Hyper-V VMs or Windows Server 2012 R2 Failover Clusters running the Scale-out File Server role. See Cluster OS Rolling Upgrade.
File and Storage Services Yes Yes Varies by sub-feature No
Hyper-V Yes. (When the host is part of a cluster with Cluster OS Rolling Upgrade process which includes node Pause-Drain, Evict, upgrade to Windows Server 2016 and rejoin the original cluster.) No Yes No for Windows Server 2012 Failover Clusters. Yes for Windows Server 2012 R2 Failover Clusters with Hyper-V VMs or Windows Server 2012 R2 Failover Clusters running the Scale-out File Server role. See Cluster OS Rolling Upgrade.
Print and Fax Services No No Yes (Printbrm.exe) No
Remote Desktop Services Yes, for all sub-roles, but mixed mode farm is not supported Yes, for all sub-roles, but mixed mode farm is not supported Yes No
Web Server (IIS) Yes Yes Yes No
Windows Server Essentials Experience Yes N/A – new feature Yes No
Windows Server Update Services Yes Yes Yes No
Work Folders Yes Yes Yes Yes from WS 2012 R2 cluster when usingCluster OS Rolling Upgrade.

Credit to Mike Brannigan for bringing this to my attention.

Microsoft Azure Concepts – SQL Data Warehouse

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azure-sql-data-warehouseIt has been widely reported that data growth is increasing year on year with more data being created in the past two years than in our entire history before this point.

Along with the increase in information is the requirement to report, analyse, manipulate and interrogate the data set.

With traditional on-premises solutions, you aim to size the Data Warehouse for peak workloads so that you have enough compute and storage performance to deal with demand.  This capital investment then leads to further question.

  • What about off-peak times, can I make use of the hardware for other purposes?
  • Who is going to manage and maintain the firmware, operating systems?
  • How are we going to expand the environment or are we sizing it for the future now?
  • What if our predicted future requirement calculations are wrong, can we expand compute and storage, also will we have the budget available?

To answer these questions and more Microsoft introduced Azure SQL Data Warehouse in July 2016.

What Is Azure SQL Data Warehouse?

Azure SQL Data Warehouse is a PaaS offering, meaning that there is no requirement to manage the hardware or operating system, you just consume what you need at any given time.

It’s built on a distributed architecture which decouples storage from compute, meaning you don’t have a hard tie between increasing compute power with storage capacity.  Therefore if you require more storage capacity but your compute resources are adequate you only pay for the extra storage.t

Microsoft use a Massively Parallel Processing system which means that each compute node contributes to the overall workload as shown in the diagram below.  This is versus a traditional Symmetric Multiprocessing system in which you scale resources up for example a SQL Server.


Each node takes a slice of the data from the database, when a query is ran a co-ordination task is undertaken to ensure that the query execution is performed in the most optimal way.

How Is It Priced?

Microsoft use the concept of a Data Warehousing Unit or DWU which is an underlying measure of the compute power of the database.

DWU are charged per hour and you can scale up or down within seconds between different tiers.

For example if it took 15 minutes to load three tables and run a report on 100 DWU then I would expect it to take 5 minutes to load the same tables and run the report on 300 DWU.

As well as the DWU cost thereis also a storage cost which is charged per GB on Azure Premium Storage.

One of the excellent features is that you can ‘pause’ your SQL Data Warehouse which means that you don’t pay for any compute resources during this time.  Let’s look at a practical example:

8am Monday – Normal working conditions ‘un-pause SQL Data Warehouse at 300 DWU’

6pm Monday – ‘Pause SQL Data Warehouse’

8am Tuesday – End of month reporting ‘un-pause SQL Data Warehouse and increase to 3000 DWU’

10am Tuesday – End of month reporting complete ‘scale down to 300 DWU’

For more details on pricing, please see SQL Data Warehouse Pricing.


Azure SQL Data Warehouse is designed differently and also behaves differently to an on-premises environment.

Those of us who are used to making design decisions in a VMware network environment based on load distribution will be vaguely familiar with the concepts of a distribution key.  A distribution key determines the method in which Azure SQL Data Warehouse spreads data across nodes.

When data is loaded from a table into Azure SQL Data Warehouse it is split into 60 distributions (buckets of data) which are attached to different compute nodes.

Hash Distribution – A unique field within a table is used to distribute data.  The entry within the field is hashed and those fields returning the same value will be placed on the same compute node for example:

Row 1 Trainer would go to Compute Node 1

Row 2 Sock would go to Compute Node 2

Row 3 Trainer would go to Compute Node 1

Row 4 Shoe would go to Compute Node 3

The main drawback of Hash Distribution is you could end up with an data skew causing uneven workload spread across your distributions.

Round-Robin Distribution – Each row within the table is distributed to a different compute node for example:

Row 1 Trainer would go to Compute Node 1

Row 2 Sock would go to Compute Node 2

Row 3 Trainer would go to Compute Node 3

Row 4 Shoe would go to Compute Node 4

Table Types

Azure SQL Data Warehouse offers three different table types:

  1. Clustered Columnstore – Organises records by columns, has a high compression ratio but without secondary indexes.  Note this is the default table type in Azure SQL Data Warehouse.
  2. Heap – No index on the data, but much faster at loading as has no compression.  But does allow for secondary indexes.
  3. Clustered B-Tree Index – A table that is organised on a sorted column which is often the clustering key.  Enables fast single lookup, but doesn’t support compression.  But does allow for secondary indexes.

Azure SQL Data Warehouse users the concept of Table Partitioning, this is where a top level table is split into different data buckets as shown in the diagram below.


This approach has a number of benefits which include the ease of loading and removing data, the ability to target specific table partitions for maintenance operations and overall increased performance.

Within Azure SQL Data Warehouse it is best to use lower granularity partition schemes for example weekly or monthly rather than daily.

Loading Data into Azure SQL Data Warehouse

When loading data into Azure SQL Data Warehouse we have to bear in mind that it is a Massively Parallel Processing system which therefore means we want to load as much data in parallel as possible.

Depending on the DWU are you paying for, depends on the number of reader threads which are available to you. These are threads that read data in parallel. Note that the number of writer threads into the MPP remain the same.

DWU Readers
100 8
200 16
300 24
400 32
500 40
600 48
1,000 60

As you can see your DWU has a direct impact on how fast you can load data.

When data is read into Azure SQL Data Warehouse, you can choose to use single client loading methods such as SSIS and Azure Data Factory. Alternatively you can use PolyBase for parallel loading.

Loading data using a single-client methodology means that your ‘Control Node’ becomes your bottleneck.  A ‘Control Node’ is a special category of node that receives all the connections and sends the queries onto the compute nodes.


The ‘Control Node’ is a static item and doesn’t increase or decrease depending on the amount of DWU you add or remove.  Therefore meaning that if you load with SSIS, then the ‘Control Node’ could become a bottleneck.

Loading data with PolyBase which is recommended for parallel loading means that data is taken straight into the compute nodes without the need for a ‘Control Node’.

Data is usually exported from SQL and then loaded into Azure Blob Storage as a CSV before being imported into the compute nodes using an automation routine.


This means that using PolyBase loading scales more efficiently and is usually much faster.


Built into Azure SQL Data Warehouse is a backup functionality which provides a data warehouse consist backup every four to eight hours.  This means that you will receive between three and six backups per day which are stored for seven days.

You can also trigger snapshots of the Blob Storage on which the Azure SQL Data Warehouse resides if you want a one off or more frequent backup schedule.  Note this would be triggered by PowerShell and automated by Azure Automation see Using Azure PowerShell with Azure Storage.

Migration Utility

Microsoft provides a Migration Utility that supports SQL Server 2012 or above and Azure SQL Databases.  It provides a report pointing out possible migration issues which could be encountered when using Azure SQL Data Warehouse.  It can help to assist with schema and data migrations.

Microsoft Azure Concepts – Mobile Apps

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Mobile Apps are a recent phenomenon in Microsoft Azure and form part of App Services, which are specifically targeted at the delivery applications on mobile technology.

What Are Mobile Apps

In a nutshell, Mobile Apps are a PaaS offering, which means that the developer can create and manage mobile applications without needing to worry about managing and maintaining the underlying operating system.

Depending on the App Service Plan chosen, will entitle you to a number of features for your website which are:

  • Amount of disk space
  • SLA
  • Number of instances
  • Auto Scale
  • Backups
  • Geo Distributed Deployment
  • Custom Domain
  • Staging Environment
  • Offline Sync
  • Active Mobile Devices

Most businesses would choose the Standard Tier as this provides an SLA of 99.95% along with Auto-Scale.  More information on the types of App Service plans can be found here.

As part of the Mobile Apps PaaS offering identity and access are included as this is underpinned via Azure Active Directory.  Meaning that if you use Azure AD Connect in either same sign on or single sign on you have the ability to provide enterprise level authentication using your on-premises directory services.  Or if the mobile application is going to be standaline, the ability to use social providers such as Facebook, Google or Twitter is provided.

Offline Data

Mobile coverage is an issue in the UK, I can be driving on the M1 and in some areas have no phone signal.  This is a challenge when developing mobile applications as you can’t expect the user to always be in an area that has excellent coverage.  Built into Mobile Apps is an offline sync client which uses SQL Lite to cache and modify data locally on the end device.  It works on a push basis with the end device providing the notification to Mobile Apps to receive data over REST API’s.

Offline sync is available on Andiod, Cordova, iOS, Windows.

Notification Hubs

Integrated with Mobile Apps are Azure Notification Hubs.  These allow you to send notifications to mobile devices using a Platform Notification System (PNS).  In the same way that offline sync is available across platforms, so are notifications hubs.

Typical use cases for Azure Notification Hubs are:

  • Breaking news or offers
  • Updates per location e.g. travel issues
  • Updates per group e.g. people with a similar interest
  • One time passwords for MFA

Upload Content

Mobile apps by their very nature usually require input from the client device.  This could be in the form of uploading documents or images to Azure Blob storage.  To achieve this you would use a Shared Access Signature (SAS), the client device calls the Mobile App to generate a SAS which passes a storage token back to the client device enabling the user to write data to your Azure Blob storage account on a time restricted basis.

The diagram below provides a logical overview of the use of mobile apps and how the components integrate.



Microsoft Azure – UK Datacentres

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azureMicrosoft have made Azure and Office 365 generally available from UK datacentres in London, Durham and Cardiff.

The go live of these services means that customers who had concerns regarding data sovereignty and compliance, now have some of their concerns alleviated.

It is important to understand that some services are not available from UK datacentres yet, these include:

  • Storage Import and Export which could be a factor if you want to seed data
  • Azure Site Recovery, meaning that you cannot protect your Azure based VM’s across regions using this service

A full list of services available in the Europe are located here.

Thanks to @sideshowtob for the Resource Group picture below.



Azure App Service Migration Assistant Tool

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App ServiceOne of my colleagues brought the Azure App Service Migration Assistant Tool to my attention recently.

App Services are used to provide PaaS type offerings with Microsoft controlling items such as deployment slots, load balancing, backups and operating system patches, with the consumer focusing on the IIS instance.

App Services are quite appealing to customers as it allows them to pass over the infrastructure elements to Microsoft enabling them to deal with managing and maintaining their websites.

So the question is, how do I know if my website is ready to become a Microsoft Azure App Service?  This is where the Azure App Service Migration Assistant Tool comes into play.  It scans the IIS server and determines readiness for migration to Microsoft Azure including:

  • Websites running on the IIS server.
  • Applications and virtual directories configured under each site.
  • Application pools used by the sites and applications and their settings.
  • HTTP and HTTPS bindings used by the sites.
  • Databases defined in web.config using connectionString attribute.