Partition-Based Sync - Kotlin SDK

Partition Value

When you select Partition-Based Sync for your backend App configuration, your client implementation must include a partition value. This is the value of the partition key field you select when you configure Partition-Based Sync.

The partition value determines which data the client application can access.

You must provide a partition value when you open a synced realm.

Open a Partition-Based Sync Realm

To open a Partition-Based Sync realm, pass a user, a partition, and a set of Realm object schemas to SyncConfiguration.Builder(). Then, pass the configuration to Realm.open() to open an instance of the realm:

val app = App.create(YOUR_APP_ID)
runBlocking {
    val user = app.login(Credentials.anonymous())
    val config =
        SyncConfiguration.Builder(user, PARTITION, setOf(/*realm object models here*/))
            // specify name so realm doesn't just use the "default.realm" file for this user
            .name(PARTITION)
            .build()
    val realm = Realm.open(config)
    Log.v("Successfully opened realm: ${realm.configuration.name}")
    realm.close()
}

Configure a Partition-Based Sync Realm

To adjust specific configuration settings, use the options provided by SyncConfiguration.Builder:

val app = App.create(YOUR_APP_ID)
runBlocking {
    val user = app.login(Credentials.anonymous())
    val config =
        SyncConfiguration.Builder(user, PARTITION, setOf(/*realm object models here*/))
            .maxNumberOfActiveVersions(10)
            .waitForInitialRemoteData()
            .name("realm name")
            .build()
    val realm = Realm.open(config)
    Log.v("Successfully opened realm: ${realm.configuration}")
    realm.close()
}

Check Upload & Download Progress for a Sync Session

You can monitor the upload and download progress of a sync session. The sync session starts when you open a synced realm. For more information, refer to Manage a Sync Session.

To monitor Sync upload and download progress, call SyncSession.progressAsFlow()

This method returns a Flow of Progress events. Progress provides the total number of transferrable bytes and the remaining bytes to be transferred.

syncSession.progressAsFlow() takes two arguments:

• A Direction enum that can be set to UPLOAD or DOWNLOAD. This specifies that the progress stream tracks uploads or downloads.

• A ProgressMode enum that can be set to either:

  • INDEFINITELY: Sets notifications to continue until the callback is unregistered.

  • CURRENT_CHANGES: Sets notifications to continue until only the currently transferable bytes are synced.

val stream = realm.syncSession.progressAsFlow(
    Direction.UPLOAD, ProgressMode.CURRENT_CHANGES
)
stream.collect { progress ->
    if (progress.transferableBytes == progress.transferredBytes) {
        Log.i("Upload complete")
    }
}

Migrate from Partition-Based Sync to Flexible Sync

You can migrate your App Services Device Sync Mode from Partition-Based Sync to Flexible Sync. Migrating is an automatic process that does not require any changes to your application code. Automatic migration requires Realm Kotlin SDK version 1.9.0 or newer.

Migrating enables you to keep your existing App Services users and authentication configuration. Flexible Sync provides more versatile permissions configuration options and more granular data synchronization.

For more information about how to migrate your App Services App from Partition-Based Sync to Flexible Sync, refer to Migrate Device Sync Modes.