RDS 2016 - SQL Server mirror wont work RRS feed

  • Question

  • Hi,

    We are having an RDS 2016 enviroment, consisting of the following servers (domain name have been replaced):

    S1TSCB01.domain.local - Connection Broker1

    S1TSCB02.domain.local - Connection Broker2

    S1TSCBHA01.domain.local - DNS Round-Robin for HA Connection brokers

    S1TSGW03.domain.local - Gateway and Webfrontend

    S1SQL01.domain.local - SQL Mirror (Partner)

    S1SQL02.domain.local - SQL Mirror (Primary)

    Our issues is, that when flipping the Mirrored SQL database, its not possible to connect to the RDSH servers.

    We are using the following Database Connection String, and ive made sure, that the Native SQL Client is installed:

    DRIVER=SQL Server Native Client 11.0;SERVER=s1sql02.domain.local;Failover_Partner=s1sql01.domain.local;Trusted_Connection=Yes;APP=Remote Desktop Services Connection Broker;DATABASE=S1TSCBHA01

    We are getting these error messages in the Event Viewer on the primary Connection Broker:

    Source: TerminalServices-SessionBroker
    Event ID: 2048
    Level: Warning
    The Remote Desktop Connection Broker server detected that the database is not available and will notify all Remote Desktop Connection Broker plug-ins.

    Source: TerminalServices-SessionBroker
    Event ID: 2072
    Level: Error
    Connection Broker cannot connect to SQL database. Please ensure policy and firewall settings are properly configured to allow connections to the SQL Server. If the SQL Server is configured to listen on a dynamic port either change the port to a static TCP port or enable outgoing UDP traffic to port 1434 from the Connection Broker

    Source: TerminalServices-SessionBroker
    Event ID: 1283
    Level: Information
    Remote Desktop Services successfully left a farm on the Connection Broker server S1TSCB02.domain.local;S1TSCB01.domain.local.

    Source: TerminalServices-SessionBroker
    Event ID: 2056
    Level: Error
    The Remote Desktop Connection Broker server could not enumerate the targets for the provider named NULL from the database.

    Pooled virtual desktop collection name: NULL
    Error: Logon to the database failed.

    When restarting the Remote Desktop Connection Broker service, then clients are able to connect again.

    Why is this happening, and what can we do to solve this?

    The mirroring is working for other applications, and RDS is the only application, that is having the issue.

    Thanks in advance.!

    Monday, November 27, 2017 12:39 PM

All replies

  • I  have same issue
    Monday, November 27, 2017 12:52 PM
  • We also have the same issue, but cannot find any errors in the setup. We have followed best practice according to how RDS and SQL mirroring should be deployed all the way through.
    • Edited by Tkmoeller Tuesday, November 28, 2017 7:58 AM
    Tuesday, November 28, 2017 7:55 AM
  • When restarting the Remote Desktop Connection Broker service, then clients are able to connect again.


    On which RD CB server that restart RD CB services resolves the issue?

    In mirror server side, please ensure Database has sysadmin, owner, the public right to the security group of RD brokers.

    Window server 2012: RD Connection Broker high availability with SQL Server

    Best Regards,


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    Tuesday, November 28, 2017 7:55 AM
  • Hi,

    Sorry for the late answer, but been busy with other projects.

    We usually restart the Connection Broker service on both CBs, since we are running loadbalancing (round-robin), so we cant tell which one the end-user will connect to.

    In mirror server side, please ensure Database has sysadmin, owner, the public right to the security group of RD brokers.

    Im not sure how to grant this permission ?

    I dont believe you / Microsoft wants us, to give the group that includes the Connection Brokers sysadmin access.

    This is still a major issue for us, so any help would be much appreciated.

    Tuesday, January 2, 2018 8:59 AM
  • Kristian,

    I’ve had this issue for over a year now but under slightly different circumstances.

    My RDCB service hangs with the error in the logs of cannot contact SQL database when my SQL database is being backed up by Veeam (VMware hypervisor).

    DB server gets frozen for snapshot, RDCB cannot contact SQL DB and errors in the logs but service is still running and i end up restarting the service.

    Mine is that bad that i have a batch script run after the VM is thawed from backup that restarts the RDCB service.

    i have raised 3 threads throughout the technet forums on this RDCB service timeout issue when not being able to contact the server but yet to get a decent answer from anyone in MS.

    I believe the service times out and locks up after X seconds or something along those lines and if it tries to contact the SQL DB when its in a brief moment of being unavailable everything collapses in the service.

    I would love to give you a glimmer of hope but it took MS well over 6 months to fix the USB passthrough issue in 2016 when it first came out (physically blue screened session hosts!) and ive yet to have any acknowledgement from MS on any of my posts on this topic other than “make sure DB permissions are right” and your “RDCB must have a connection issue”.

    I’ve even gone as far as building 3 new RDCB servers and 2 new databases including servers to go with and yet i keep seeing this issue.The fact that your seeing it on an SQL mirror adds even more fuel to my theory of it being a service communication bug.

    Thursday, February 15, 2018 11:30 PM