Configuring an SQL Server or PostgreSQL database for Machine Learning Server


This content is being retired and may not be updated in the future. The support for Machine Learning Server will end on July 1, 2022. For more information, see What's happening to Machine Learning Server?

Applies to: Machine Learning Server, Microsoft R Server 9.x

The operationalization feature for Machine Learning Server (and R Server) installs and uses a local SQLite database by default to store internal information. Later, you can update the configuration to use another database locally or remotely. This is useful when you want to use a remote database or when you have multiple web nodes.

The database provides internal storage for the sessions, web services, snapshots, and other entities created as a result of operationalization. When a request comes in to a web node (for example, to consume a service), the web node connects to the databases, retrieves parameters for the service, and then sends the information to a compute node for execution.

Consider the size of the machine hosting this database carefully to ensure that database performance does not degrade overall performance and throughput.

This feature uses a SQLite 3.7+ database by default, but can be configured to use:

  • SQL Server (Windows) Professional, Standard, or Express Version 2008 or greater
  • SQL Server (Linux)
  • Azure SQL DB
  • Azure Database for PostgreSQL
  • PostgreSQL 9.2 or greater (Linux)


Any data that was saved in the default local SQLite database will not be migrated to a different DB, if you configure one.

To use a different local or remote database, do the following:


These steps assume that you have already set up SQL Server or PostgreSQL as described for that product.

Create this database and register it in the configuration file below BEFORE the service for the control node is started.

  1. On each web node, stop the service.

  2. Update the database properties to point to the new database as follows:

    1. Open the configuration file, <web-node-install-path>/appsettings.json.

    2. Locate the ConnectionStrings property block.

    3. Within that property block, locate the type of database you want to set up.

      • For SQL Server or Azure SQL DB, look for "sqlserver": {.

      • For PostgreSQL or Azure Database for PostgreSQL, look for "postgresql": {.

    4. In the appropriate database section, enable that database type by adding the property "Enabled": true,. You can only have one database enabled at a time.

      For example:

       "ConnectionStrings": {
               "sqlserver": {
                   "Enabled": true,
    5. Add the connection string.

      For SQL Server Database (Integrated Security), use your string properties that are similar to:

      "Connection":  "Data Source=<DB-SERVER-IP-OR-FQDN>\\<INSTANCE-NAME>;Initial Catalog=<DB-NAME>;Integrated Security=True;"

      For SQL Server Database (SQL authentication), use your string properties similar to:

      "Connection":  "Data Source=<DB-SERVER-IP-OR-FQDN>\\<INSTANCE-NAME>;Initial Catalog=<DB-NAME>; Integrated Security=False; User Id=<USER-ID>;Password=<PASSWORD>;"

      For PostgreSQL Database, use your string properties:

      "Connection":  "User ID=<DB-USERNAME>;Password=<USER-PASSWORD>;Host=<DB-SERVER-IP-OR-FQDN>;Port=5432;Database=<DB-NAME>;Pooling=true;"
    6. For better security, we recommend you encrypt the connection string for this database before adding the information to appsettings.json.

      1. Encrypt the connection string.

      2. Copy the encrypted string returned by the administration utility into "ConnectionStrings": { property block and set "Encrypted": to true. For example:

       "ConnectionStrings": {
               "sqlserver": {
                   "Enabled": true,
                   "Encrypted": true,
    7. Save the changes you've made to appsettings.json.

  3. Open the database port on the remote machine to the public IP of each web node as described in these articles: SQL Server | PostgreSQL

  4. Start the web node and the database is created upon restart.

  5. Run the diagnostic tests to ensure the connection can be made to your new database.