I am having data corruption in my mobile app (Ionic 1), in very occasional cases.
The app is working with users logging to a remote CouchDB server. Each user has its own db in the server. There is only one session at a time in the app, but it may happen that user A uses the app, logs out, then user B logs in to use the app.
Locally, the app has one unique PouchDB, which is created on login, then live-synchronized with the user's remote couchDB, then destroyed on logout.
Problem: in very random and unfrequent cases that I cannot reproduce, some data of user A appear in the data of user B! and more over, some data of user A are destroyed (maybe transferred to B, not sure).
So, I was wondering what happens if I call PouchDB.destroy while a live sync is running (PouchDB.replicate with options { live: true, retry:true, continuous:true } in both ways: local to remote and remote to local). Is destroy doing something to cleanly stop the replication? If not, it might explain that some data are transferred from old-local A database to new-local B database (I have tried to browse the PouchDB source code but got lost in it. I could just see that Replication.cancel is called from its onDestroy method, but not sure it handles things right for my case).
Many thanks for any help!
The safest way to destroy a database during replication is to first call cancel() and then wait for the complete event. For instance:
var sync = db.sync(otherDB, {live: true, retry: true});
sync.on('complete', function () {
db.destroy().then(/* ... */);
});
/* ... */
sync.cancel(); // will trigger a 'complete'Hope that helps!