Configure master instance of SQL Server Big Data Clusters

Applies to: yesSQL Server 2019 (15.x)

Configure master instance of SQL Server Big Data Clusters.

Server configuration settings cannot be configured for SQL Server master instance at deployment time. Starting in CU9, Big Data Clusters includes a configuration management feature that enables administrators to alter or tune various parts of the Big Data Cluster post-deployment and get deeper insights into the configurations running in their big data cluster.

This article describes a temporary workaround on how to configure settings, including: SQL Server edition, enable or disable SQL Server Agent, enable specific trace flags, enable/disable customer feedback, or domainmapping.

To change any of these settings, follow these steps:

  1. Create a custom mssql-custom.conf file that includes targeted settings. The following example enables SQL Agent, telemetry, sets a PID for Enterprise Edition, and enables trace flag 1204:

    userRequestedLocalAuditDirectory = /tmp/audit
    pid = Enterprise
    traceflag0 = 1204
  2. Copy mssql-custom.conf file to /var/opt/mssql in the mssql-server container in the master-0 pod. Replace <namespaceName> with the big data cluster name.

    kubectl cp mssql-custom.conf master-0:/var/opt/mssql/mssql-custom.conf -c mssql-server -n <namespaceName>
  3. Restart SQL Server instance. Replace <namespaceName> with the big data cluster name.

    kubectl exec -it master-0  -c mssql-server -n <namespaceName> -- /bin/bash
    supervisorctl restart mssql-server


If SQL Server master instance is in an availability groups configuration, copy the mssql-custom.conf file in all the master pods. Note that each restart will cause a failover, so you must make sure you are timing this activity during downtime periods.

Known limitations

  • The steps above require Kubernetes cluster admin permissions
  • You cannot change the server collation for SQL Server master instance of the big data cluster post deployment.

Next steps

For more information about deploying SQL Server Big Data Clusters, see Get started with SQL Server Big Data Clusters.