SQL server Basic Availability Group and License issue

Chris kulisz 21 Reputation points
2020-09-11T19:52:34.103+00:00

Scenario:
SQL Standard 2016+
2 Nodes
2 BAG for 2 DB

If you have a DB failure where BAG(1) switches from Node(1) to Node(2) and BAG(2) Does not have a failure so stays Primary on Node(1)
You are technically now consuming 2 licenses.
This is not an ideal use case as there should be something built in to handle the Case where a Single BAG on Node failing should cause Other BAG to also fail to Node(2) is Node(2) is available for the other BAG's

I do understand that there are multiple use cases ..
Node(1) could have DB without BAG and some DB's on BAG.
and BAG(1) could be setup as Node(1-2) while BAG(2) setup as Node(1-3) etc..
But for a basic dedicated SQL Standard Server if you create 2 Nodes and Multiple BAG's between those 2 Nodes You should not automatically have a license usage problem in case of a single BAG fail over.
There are some things you might want to do and jury rig the system so that this works by firing On fail over events and doing some automated work but this is not a standard supported behavior. Is there plans to fix this GAP in the future?

SQL Server
SQL Server
A family of Microsoft relational database management and analysis systems for e-commerce, line-of-business, and data warehousing solutions.
8,576 questions
Accepted answer
  1. David Browne - msft 3,756 Reputation points
    2020-09-11T21:03:18.593+00:00

    Having only one Basic Availibility Group failover should be a very rare occurance. It will really only happen if you enable "Database-level Health Detection" and have an issue that affects only one of your databases. So you can disable "Database-level Health Detection", and document that you have monitoring in place to alert you to any unplanned failovers, that's probably enough. Note that there will always be brief windows where you run on both nodes during patching, as you have to fail-over the BAG's one-at-a-time.

    Is there plans to fix this GAP in the future?

    There's no roadmap information available yet for the next version of SQL Server, but features do tend to migrate from Enterprise Edition to Standard Edition over time.

    You can provide feedback here, and/or vote for this related feedback item.

    And, of course, AlwaysOn Failover Cluster Instances support multiple databases with instance-level failover on SQL Server Standard Edition.

3 additional answers

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  1. Shashank Singh 6,211 Reputation points
    2020-09-12T07:03:30.823+00:00

    If you have a DB failure where BAG(1) switches from Node(1) to Node(2) and BAG(2) Does not have a failure so stays Primary on Node(1).You are technically now consuming 2 licenses.

    AFAIK Microsoft is not going to charge you with penalty if let us say for one hour or 2-3 hour due to failover you have one instances active on passive node. It should be your moral conscience to make configuration such that passive node is truly passive.

    But ofcourse official answer has to come from MS as to how to handle such cases.

  2. Poonam Bhatia 1 Reputation point
    2020-09-12T15:33:07.14+00:00

    The AlwaysOn_health Extended Events session was introduced in SQL Server 2012 to assist database administrators with root-cause diagnosis when troubleshooting Availability Groups.and seems you have enable the db level health dedection that is why it occurs.as of now, this is really a limitation of BAG.

  3. CathyJi-MSFT 20,671 Reputation points Microsoft Employee
    2020-09-14T06:02:34.183+00:00

    Hi @Chris kulisz ,

    Basic availability groups different from traditional AG, it has many limitations. Such as, basic availability group supports a failover environment for a single database. Having multiple Basic availability groups connected to a single instance of SQL Server. Refer to this document.

    As David mentioned, you can submit your issue to the Microsoft feedback.

    Best regards,
    Cathy