SQL Server

Component format

To setup SQL Server state store create a component of type state.sqlserver. See this guide on how to create and apply a state store configuration.

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
spec:
  type: state.sqlserver
  version: v1
  metadata:
  - name: connectionString
    value: <REPLACE-WITH-CONNECTION-STRING> # Required.
  - name: tableName
    value: <REPLACE-WITH-TABLE-NAME>  # Optional. defaults to "state"
  - name: keyType
    value: <REPLACE-WITH-KEY-TYPE>  # Optional. defaults to "string"
  - name: keyLength
    value: <KEY-LENGTH> # Optional. defaults to 200. You be used with "string" keyType
  - name: schema
    value: <SCHEMA> # Optional. defaults to "dbo"
  - name: indexedProperties
    value: <INDEXED-PROPERTIES> # Optional. List of IndexedProperties.
  - name: metadataTableName # Optional. Name of the table where to store metadata used by Dapr
    value: "dapr_metadata"
  - name: cleanupIntervalInSeconds # Optional. Cleanup interval in seconds, to remove expired rows
    value: 300

If you wish to use SQL server as an actor state store, append the following to the yaml.

  - name: actorStateStore
    value: "true"

Spec metadata fields

Create Azure SQL instance

Follow the instructions from the Azure documentation on how to create a SQL database. The database must be created before Dapr consumes it.

Note: SQL Server state store also supports SQL Server running on VMs and in Docker.

In order to setup SQL Server as a state store, you need the following properties:

• Connection String: The SQL Server connection string. For example: server=localhost;user id=sa;password=your-password;port=1433;database=mydatabase;
• Schema: The database schema to use (default=dbo). Will be created if does not exist
• Table Name: The database table name. Will be created if does not exist
• Indexed Properties: Optional properties from json data which will be indexed and persisted as individual column

Create a dedicated user

When connecting with a dedicated user (not sa), these authorizations are required for the user - even when the user is owner of the desired database schema:

• CREATE TABLE
• CREATE TYPE

TTLs and cleanups

This state store supports Time-To-Live (TTL) for records stored with Dapr. When storing data using Dapr, you can set the ttlInSeconds metadata property to indicate after how many seconds the data should be considered “expired”.

Because SQL Server doesn’t have built-in support for TTLs, Dapr implements this by adding a column in the state table indicating when the data should be considered “expired”. “Expired” records are not returned to the caller, even if they’re still physically stored in the database. A background “garbage collector” periodically scans the state table for expired rows and deletes them.

You can set the interval for the deletion of expired records with the cleanupIntervalInSeconds metadata property, which defaults to 3600 seconds (that is, 1 hour).

• Longer intervals require less frequent scans for expired rows, but can require storing expired records for longer, potentially requiring more storage space. If you plan to store many records in your state table, with short TTLs, consider setting cleanupIntervalInSeconds to a smaller value - for example, 300 (300 seconds, or 5 minutes).
• If you do not plan to use TTLs with Dapr and the SQL Server state store, you should consider setting cleanupIntervalInSeconds to a value <= 0 (e.g. 0 or -1) to disable the periodic cleanup and reduce the load on the database.

The state store does not have an index on the ExpireDate column, which means that each clean up operation must perform a full table scan. If you intend to write to the table with a large number of records that use TTLs, you should consider creating an index on the ExpireDate column. An index makes queries faster, but uses more storage space and slightly slows down writes.

CREATE CLUSTERED INDEX expiredate_idx ON state(ExpireDate ASC)

Related links

• Basic schema for a Dapr component
• Read this guide for instructions on configuring state store components
• State management building block