Do You Have to License Your Standby SQL Server?

Licensing
20 Comments

Businesses who need high availability and disaster recovery usually want three servers:

  1. A primary SQL Server where all the writes & reads take place
  2. A high availability SQL Server sitting right next to the primary, in the same data center, keeping up with its writes, and
  3. A disaster recovery SQL Server sitting in another city or region, keeping up with the writes, but not necessarily in real time – the writes here are usually asynchronous

There are several different techniques we can use to keep those in sync, like failover clustering, Always On Availability Groups, SAN replication, log shipping, and database mirroring.

Regardless of which technology you use, there’s an important question: do you have to license the standby SQL Servers, aka #2 and #3? Since November 2019, you don’t have to pay licensing for those SQL Servers in most circumstances. Microsoft changed the licensing terms when SQL Server 2019 came out.

As long as your licensing is covered under Software Assurance, you get several new benefits including:

  • One high availability server is free
  • One disaster recovery server is free
  • You can offload corruption checks, full backups, and log backups to these servers too
  • But you still can’t query them. As soon as you start offloading end user queries onto them, they need to be fully licensed.

Isn’t that awesome? And the best thing is that you don’t even have to be running SQL Server 2019 in order to get those benefits! As long as you’re current on Software Assurance, you get this on any supported version.

This is the kind of thing that really makes an impact on your high availability and disaster recovery architectures, and I’ll be talking about that on Thursday, June 17th.

Previous Post
Free Webcast: Architecture Design for SQL Server High Availability & Disaster Recovery
Next Post
Announcing My 2021/2022 Training Class Schedule

20 Comments. Leave new

  • Steve Sc AZ
    May 27, 2021 5:08 pm

    For option #2, can it be in a read-only mode so that you can do reporting off of it?

    Reply
    • Doesn’t this address your question? “But you still can’t query them. As soon as you start offloading end user queries onto them, they need to be fully licensed.”

      Reply
  • Leo Mclovin
    May 27, 2021 8:40 pm

    Does this apply also for BASIC availability groups on Standard Edition?

    Reply
    • The SQL 2019 Licensing Guide doesn’t limit the HA/DR methodology, and actually says: “For the purposes of this guide, we are not drawing a distinction in how high availability is being implemented,”
      However since BASIC AGs only gives a singe secondary you’re 3rd & 4th servers (yes, the guide says you can actually have a 4th one in Azure) would need to use Log Shipping.
      The only underlying requirement is a licensed server with SA.
      From the guide:
      For each on-prem server OSE licensed with SQL Server 2019 and covered by active SA, customers can use the
      following passive replicas in anticipation of a failover event:
      • One passive fail-over replica for High Availability in a separate OSE
      • One passive fail-over replica for Disaster Recovery in a separate OSE
      • One passive fail-over replica for Disaster Recovery in a single VM on Azure

      Reply
      • Leo Mclovin
        May 27, 2021 11:25 pm

        Nice points Miller, tks for the tips. This is a huge incentive for small clients to enroll in SA. I’m a big noob regarding MSSQL HA/DR methods. I’m really looking forward Brent’s next webinar about it.

        Reply
    • Fraser Rackham
      May 28, 2021 12:58 pm

      Anyone know how you’d take advantage of this in Azure sql? I can tell from another comment that you *can*, but can’t see *how*.

      Reply
  • I’ve been over the Microsoft SQL Server 2019 Licensing Guide, and as I read page page 29, you can have a 3rd free instance in Azure.

    Reply
  • Hi Brent, thanks for the great info!
    Is it only from sql 2019? Or did they change that policy back as well?
    Thanks

    Reply
  • So what happens when you license at the VM Host level? Can you split your active instances over 2 datacenters?
    This will help a lot with load balancing on the network and SAN level.
    At the moment all our primaries are in one data center and secondaries in another.

    Reply
    • That’s well outside of the scope of this blog post and webcast, sorry. For personalized help on this kind of thing, click Consulting at the top of the page. Thanks!

      Reply
  • Brent, is that true even if your SQL Servers are in the cloud, not on-prem? And what about if in AWS, not Azure — does that not count for the cloud DR server?

    The licensing guide seems to be explicit about using the words “on-prem” and “Azure”:

    “For each on-prem server with SQL Server 2019 and covered by active SA, customers can use the following passive replicas in anticipation of a failover event:
    • One passive fail-over replica for High Availability in a separate server
    • One passive fail-over replica for Disaster Recovery in a separate server
    • One passive fail-over replica for Disaster Recovery in a single VM on Azure”

    Reply
  • Thanks Brent for the post. We are designing distributed availability groups, with one AG having 2 nodes in Data Center 1(Primary is Read/Write, Secondary is read-only) and another AG with 2 nodes in another Data Center or AWS (Forwarder node, Secondary node is read-only). How does the licensing works in this scenario? Thanks.

    Reply
  • Shaun Austin
    June 11, 2021 2:21 pm

    Be careful when offloading corruption checks to a secondary. You may incur the wrath of Mr Randal https://www.sqlskills.com/blogs/paul/the-curious-case-of-whether-corruption-can-propagate-to-secondary-databases/

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Fill out this field
Fill out this field
Please enter a valid email address.

Menu