Pause or Resume a Sync Session - Java SDK

When to Pause a Sync Session

For most applications, there is no need to manually pause and resume a sync session. However, there are a few circumstances under which you may want to pause or suspend a sync session:

• You only want to sync after the user takes a specific action

• You only want to sync during a certain time of the day

• You don't want to attempt to sync when there is poor network connectivity

• You want to explicitly force a sync session to connect

In the case of poor network connectivity, continually trying to establish a network connection can drain the user's device battery.

The case of explicitly forcing a sync session to connect is most commonly related to being offline for some time. The sync client attempts to connect, and upon failure, goes into exponential backoff. After being offline for a long time, the client may not immediately reconnect. Pausing and resuming the sync session explicitly forces the connection.

When you do pause a sync session, keep these things in mind:

• If the client may be offline longer than the client maximum offline time, the client will be unable to resume syncing and must perform a client reset.

• Pausing a sync session pauses it in both directions. Changes that your app makes on the device do not sync with the backend, and changes to the data in the backend or on other devices do not sync to the device. There is no way to pause only uploads or pause only downloads.

• Do not pause a sync session if you want a client to permanently stop syncing with the backend. To permanently stop syncing, copy the contents of the synced realm into a non-synced realm, and use the non-synced realm in the client.

Do not pause sync to stop syncing for indefinite time periods or time ranges in months and years. The functionality is not designed or tested for these use cases. You could encounter a range of issues when using it this way.