Conditional sync

By default, the data management service syncs all captured data at a regular interval. Conditional sync lets you control when sync happens, so data accumulates locally until your conditions are met: sync only during off-peak hours, when connected to WiFi, after a sensor reading crosses a threshold, or based on any other logic you define.

How conditional sync works

Conditional sync uses a sensor component as a gate. You configure a sensor whose Readings() method returns "should_sync": true or "should_sync": false. At each sync interval, the data manager calls Readings() on this sensor before uploading. If the result is true, sync proceeds. If false, the cycle is skipped and data continues to accumulate locally.

The sensor is the only mechanism for conditional sync. There is no built-in rules engine or config-only option. Any logic you need goes in the sensor’s Readings() implementation. You can use an existing sensor module from the registry or write your own.

Important

If selective_syncer_name is configured but the sensor cannot be found, scheduled sync is disabled until the sensor becomes available. Make sure the sensor is correctly configured and added to the data manager’s depends_on field.

Conditional sync does not control capture

Conditional sync only controls when data is uploaded. Capture continues writing to local disk at the configured frequency regardless of whether sync is active. If the sync window is short or bandwidth is limited, the backlog from a full capture cycle may not clear in a single window. Monitor the capture directory size on constrained devices. See Manage local storage for storage management guidance.

Configure conditional sync

This example uses the sync-at-time/timesyncsensor sensor module to sync data only during a configured time window. You can substitute any sensor that returns should_sync.

1. Add the sync sensor

1. On your machine’s CONFIGURE tab, click + next to your machine part and select Component or service.
2. Search for sync-at-time/timesyncsensor and select the result.
3. Enter a name (for example, timesensor) and click Add to machine.
4. Configure the time window in the sensor’s attributes:

   {
        "start": "18:00:00",
        "end": "06:00:00",
        "zone": "America/New_York"
   }

5. Click Save.

2. Point the data manager at the sensor

The selective_syncer_name field is not available in the UI. Switch to JSON mode on the CONFIGURE tab.

Find the data management service in your config and add two fields:

• selective_syncer_name: the name of your sync sensor
• depends_on: include the sensor name so the data manager waits for it to be available

Click Save.

3. Verify conditional sync is working

1. Confirm data capture is running: check the machine’s LOGS for capture activity.
2. If you are outside the sync window, data should accumulate locally but not appear in the DATA tab.
3. When the sync window opens, check the DATA tab. Captured data should begin appearing.
4. If data appears immediately regardless of the window, check that selective_syncer_name matches the sensor name exactly and that the sensor is in depends_on.

Build a custom sync sensor

If no existing module fits your use case, you can write a sensor module that implements whatever sync logic you need: check network connectivity, compare sensor readings to a threshold, query an external API, or combine multiple conditions.

The sensor must implement the sensor API and return a "should_sync" key with a boolean value from Readings(). The data manager checks this key at each sync interval. The sensor can return additional readings alongside should_sync.

The RDK provides a helper: datamanager.CreateShouldSyncReading(bool) returns a properly formatted readings map.

1. Follow the module development guide to create a sensor module.
2. Implement Readings() to return "should_sync": true when sync should proceed and "should_sync": false otherwise.
3. Deploy the module and configure the data manager with your sensor’s name.