Firestore - Checking The Connection Status Of The Module To The Server

Question

I have noticed that after turning off the internet connection and than turning it back on (while my Android app is still running, in the background or not), it takes the Firestore module a pretty long time to regain the connection to the server (about a minute), and I can't make any Firestore operations until the connection is regained.

Is this a normal behavior? If it does, can I somehow check the Firestore module current connection status? (in order to limit my user's actions if there is a need).

Answer 1

As far as i know, there is no equivalent to Firebase Realtime Database's .info/connected in Cloud Firestore, that allows you to verify the connection status. I read on Firebase offical blog a post regarding the differences between Firebase and Firestore and i saw that this problem is in fact one of the use-cases.

The Realtime Database has native support for presence -- that is, being able to tell when a user has come online or gone offline. While we do have a solution for Cloud Firestore, it's not quite as elegant.

If you read Firestore offical documentation, you will see that there is a possible implementation of a presence system by combining Realtime Database and Firestore.

Answer 2

I'm currently testing a fix for this that seems to be working.

Step 1: Ensure the device has a data connection using Android's recommended approach

public static boolean isConnectedToInternet(@NonNull Context _context) {
    ConnectivityManager cm = (ConnectivityManager)_context.getSystemService(Context.CONNECTIVITY_SERVICE);
    if (cm == null)
        return false;
    NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
    return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
}

Step 2: Force Firestore to connect (the idea is to override Firestore's internal connection retry exponential backoff)

FirebaseFirestore.getInstance().enableNetwork()

Step 3 (optional): If you're doing this when your app is in the background, you may also want to use Android's Task API to synchronously wait until the enableNetwork() Task completes. Otherwise, the OS may think your background work is complete, and cut off your app's access to system resources (network, CPU, etc).

try { Tasks.await(FirebaseFirestore.getInstance().enableNetwork()); }
catch (Exception e) {
    Log.e(TAG, "error in Firestore enableNetwork(): ", e);
    return;
}