SQLite

Detailed information on the SQLite name resolution component

As an alternative to mDNS, the SQLite name resolution component can be used for running Dapr on single-node environments and for local development scenarios. Dapr sidecars that are part of the cluster store their information in a SQLite database on the local machine.

Configuration format

Name resolution is configured via the Dapr Configuration.

Within the Configuration YAML, set the spec.nameResolution.component property to "sqlite", then pass configuration options in the spec.nameResolution.configuration dictionary.

This is the basic example of a Configuration resource:

apiVersion: dapr.io/v1alpha1
kind: Configuration
metadata:
  name: appconfig
spec:
  nameResolution:
    component: "sqlite"
    version: "v1"
    configuration:
      connectionString: "/home/user/.dapr/nr.db"

Spec configuration fields

When using the SQLite name resolver component, the spec.nameResolution.configuration dictionary contains these options:

Field Required Type Details 示例
connectionString Y string The connection string for the SQLite database. Normally, this is the path to a file on disk, relative to the current working directory, or absolute. "nr.db" (relative to the working directory), "/home/user/.dapr/nr.db"
updateInterval N Go duration (as a string) Interval for active Dapr sidecars to update their status in the database, which is used as healthcheck.
Smaller intervals reduce the likelihood of stale data being returned if an application goes offline, but increase the load on the database.
Must be at least 1s greater than timeout. Values with fractions of seconds are truncated (for example, 1500ms becomes 1s). Default: 5s		 "2s"
timeout N Go duration (as a string).
Must be at least 1s.		 Timeout for operations on the database. Integers are interpreted as number of seconds. Defaults to 1s "2s", 2
tableName N string Name of the table where the data is stored. If the table does not exist, the table is created by Dapr. Defaults to hosts. "hosts"
metadataTableName N string Name of the table used by Dapr to store metadata for the component. If the table does not exist, the table is created by Dapr. Defaults to metadata. "metadata"
cleanupInterval N Go duration (as a string) Interval to remove stale records from the database. Default: 1h (1 hour) "10m"
busyTimeout N Go duration (as a string) Interval to wait in case the SQLite database is currently busy serving another request, before returning a “database busy” error. This is an advanced setting.
busyTimeout controls how locking works in SQLite. With SQLite, writes are exclusive, so every time any app is writing the database is locked. If another app tries to write, it waits up to busyTimeout before returning the “database busy” error. However the timeout setting controls the timeout for the entire operation. For example if the query “hangs”, after the database has acquired the lock (so after busy timeout is cleared), then timeout comes into effect. Default: 800ms (800 milliseconds)		 "100ms"
disableWAL N bool If set to true, disables Write-Ahead Logging for journaling of the SQLite database. This is for advanced scenarios only true, false