MSSQL : What should I know about licensing HA/DR scenario’s in the cloud?


This week I met a customer who described the following situation to me…


Where, to be honest, I was a it flabbergasted as I could not imagine this being true. So I read up on the matter, to see where this could possibly come from.

Over the course of the last years, I’ve been in contact with licensing way too much. Though in the end, this can really make a lot of difference in euros/dollars/… And that is what matters to the business!

Update (31 Oct 2019) :



All things I’m going to say during this post use the following posts as foundation ;


Disclaimer & Licensing discussion advice

First of all… INAL => I am not a licensing-expert. 😉

I just happen to have come into contact with Microsoft licensing way too much over the course of the years. This is mainly due that licensing has a major impact when designing IT landscapes for various customers.

Also be aware that terms do change over the years. Certainly when it comes to cloud. This was a major game change for a lot of companies, where we all can relate to cases where we saw (or even still see) vendors struggle with the shift towards this new way of thinking.

Therefore, if you are in doubt/discussion, please contact your LSP (licensing solutions partner). You can show them this post to assist in thinking in a certain logic. Though in the end, they follow a lot of training to keep up with this matter!

If you are stuck, I would advise to open up a support case and ask the question. This removes any doubt as you’ll get an answer “in writing”, on which you can bank. Often I see customer trying this via the traditional sales channels. How odd it may seem, I advise against it. I’ve seen many situations end bad due to this. Licensing is a really a trade on its own.


The “basics” are out of scope

At the moment I’m assuming you are already familiar with the basics of licensing per core or via server/cal. So I will not touch this topic in this post. Check the licensing guide if you are unfamiliar with this topic.


Software Assurance

Software Assurance, or SA, comes with various benefits. Many organizations think the only really benefit comes through the ability to upgrade your product at no additional cost when it’s covered by SA. Though there are a lot of additional benefits, like ;

  • Planning/Training/Deployment Vouchers
  • E-Learning
  • Home Usage
  • Failover Rights
  • License Mobility

For SQL server, the following benefits apply ;


So today we’ll take a look at “Failover Rights”, “Disaster Recovery” & “License Mobility”.


Disaster Recovery Rights

From the “Product Usage Rights”, a summary…

For each Instance of eligible server software Customer runs in a Physical OSE or Virtual OSE on a Licensed Server, it may temporarily run a backup Instance in a Physical OSE or Virtual OSE on either, another one of its Servers dedicated to disaster recovery, or, for Instances of eligible software other than Windows Server, on Microsoft Azure Services, provided the backup Instance is managed by Azure Site Recovery to Azure. The License Terms for the software and the following limitations apply to Customer’s use of the backup Instance.


The backup Instance can run only during the following exception periods:

  • For brief periods of disaster recovery testing within one week every 90 days;

  • During a disaster, while the production Server being recovered is down; and

  • Around the time of a disaster, for a brief period, to assist in the transfer between the primary production server and the disaster recovery Server.

So having SA on your products provides you with the ability to do a failover for testing up to one week every three months. And you have the ability to use the license during a DR scenario when your production server is down.


Failover Rights

Many organisations adopt failover technologies to re-assign  workloads from a primary server to a secondary standby server when a production server fails.

A standby server that is considered ‘passive’ (and not running any active workloads or reports) would generally not require a license to be assigned. This includes back-up and restore related tasks under the passive designation.

This passive failover server rule  would commonly support situations when a primary server suffers a hardware or software failure (or is taken offline for routine maintenance or patch management) and requires the secondary ‘passive’ server to take over completely for ‘temporary’ support.

A secondary server, utilised solely to maintain a copy of the database and will never take over from the primary does also fall under the ‘passive’ designation, however the passive failover server rule will only support a single designated passive server under the allowance for each primary licensed server.

An extract of one of the first advisories published by Microsoft ;

“When doing failover support, a server is designated as the passive server. The purpose of the passive server is to absorb the data and information held in another server that fails. A passive server does not need a license, provided that the number of processors in the passive server is equal or less than those of the active server. The passive server can take the duties of the active server for 30 days. Afterward, it must be licensed accordingly


License Mobility

License mobility is the ability to move licenses access server farms. This motion behind this term is that licenses can be reassigned for a long term basis. So when you are migrating servers or in a DR scenario. In addition, licenses may be reassigned within one farm as often as needed.

An extract of the product usage rights ;

License Mobility Across Server Farms

Under License Mobility Across Server Farms, Customer may reassign any of its Licenses which are designated as having License Mobility and for which it has SA to any of its Licensed Servers located within the same Server Farm as often as needed. Customer may also reassign these Licenses from one Server Farm to another, but not on a short-term basis (i.e., not within 90 days of the last assignment). Products used for Self-Hosting may be used at the same time under License Mobility Across Server Farms rights.


License Mobility through Software Assurance

Under License Mobility Through Software Assurance (SA), Customer may move its licensed software to shared servers under any of its Licenses which are designated as having License Mobility for which it has SA, subject to the requirements below. Products used for Self-Hosting may be used at the same time under License Mobility through SA rights, subject to the limitations of the Self-Hosting License Terms.


Permitted Use:

With License Mobility through SA, Customer may:

  • Run its licensed software on shared servers;

  • Access that software under access licenses and for which it has SA, and under its User and Device SLs that permit access to the Products;

  • Manage its OSEs that it uses on shared servers; and/or

  • Manage its OSEs that it uses on its servers using software that it runs on shared servers.


License Mobility : Server Farm 

Let’s take a look at the SQL Server 2016 Licensing Guide ;

All SQL Server licenses with active SA can be reassigned to another server within the server farm as often as needed; however, they can only be reassigned to another server in another server farm, or to a non-private cloud, once every 90 days.

  • A server farm may consist of up to two data centers located in time zones that are within four hours of one another and/or with the European Union (EU) and/or European Free Trade Association (EFTA).

  • A given data center may only be part of one server farm.

So for for a lot of European organizations, that would mean that DR scenario’s would can be covered by the definitions as stated for a single server farm…


Scenario Discussion Time!

Example 1 – Failover within same farm

2016-10-23-10_53_00-sql_server_2016_licensing_guide_en_us-pdf 2016-10-23-10_53_21-sql_server_2016_licensing_guide_en_us-pdf
Once you do a failover within one farm, you do not need to license the passive node. As long as you do not run active workloads on it!


Example 2 – Multiple Passive Secondaries


In a scenario with multiple secondaries, you’ll only get “one freebie”. And this is even if all secondaries are passive.

Do note that you can still do a HA+DR scenario… The DR part could be covered via the license mobility part to another zone. Though I assume that a hot standby would become tricky, as that can be considered a passive secondary, which would put you back in the above scenario.


Example 3 – DR to a 3th party provider (“cloud”)

2016-10-23-10_53_55-sql_server_2016_licensing_guide_en_us-pdfA DR scenario to the cloud is covered by license mobility. I would even go so far to say that passive secondary is covered, as long as you abide by the rules of a single server farm. As mentioned, this is feasible to most European organizations in my experience!


Example 4 – Hybrid


When taking a look at this example from the Licensing guide, I must say I’m a bit puzzled… The only reason I can think of to justify the above statement is if this is for failover reasons, thus it needs to be in the same server farm. Though, in my opinion, such a hybrid scenario is only feasible if you have either a high-speed / low latency connection (thus the license mobility – same server farm rule will probably apply) or this is to facilitate a DR scenario (where you should limit yourself to a cold standby ; log shipping?).




  • Licensing is, sadly enough, a complex field…
  • Be aware of your SA benefits
  • Educate yourself on licensing, it can save you a lot of money!

2 thoughts on “MSSQL : What should I know about licensing HA/DR scenario’s in the cloud?

    1. Have you seen anything that would indicate otherwise? (announcement or some sort)

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