Bucket shadowing not propagating deletes

[jnordberg]

When removing a document from the bucket that is being shadowed the sync bucket is not updated. New documents and updates works fine.

[jessliu]

@snej or @andreibaranouski do we have a test for this? Can we reproduce?

@jnordberg do you have any other information that you can share, such as how the document was removed, how the sync function was set up, etc.?

[jnordberg]

The document was removed from the bucket by a remove call via coucbhaselib, changes never propagate. From what i can tell sync_gateway isn't even getting a message that something happened.

sync fn

function(doc, oldDoc) {

  if (doc._deleted) {
    requireUser(oldDoc.owner);
    return;
  }

  function isValidUsername(name) {
    return (typeof name == 'string' && /^[0-9a-z]+$/.test(name));
  }

  if (!isValidUsername(doc.owner)) {
    throw ({forbidden: "invalid document owner"});
  }

  if (!(Array.isArray(doc.members) && doc.members.every(isValidUsername))) {
    throw ({forbidden: "invalid document members"});
  }

  if (oldDoc) {
    // validate changes
    if (doc.owner != oldDoc.owner) {
      // only admins can change the owner of a document
      requireRole('admin');
    }

    // only doc.members and admins can modify the document
    if (!haveUser(oldDoc.owner) && !haveUser(oldDoc.members) && !haveRole('admin')) {
      throw ({forbidden: 'no access'});
    }
  } else {
    // validate new document
    // only allow users to create documents as themselves
    requireUser(doc.owner);
  }

  channel(doc.owner, doc.members);
}

[snej]

Try turning on "CRUD" and "Shadow+" logging. You should get some logs regarding the deletion. Please post them here.

[jessliu]

@jnordberg is this issue still persisting after turning on CRUD and/or Shadow+? Also, can you try using the latest stable branch? There is a possible fix for this.

[jnordberg]

We changed our setup so we didn't need the bucket shadowing, i'll see if i can reproduce just by keeping a shadow running on our new setup

[jnordberg]

Same thing... If i delete a document via the sync gateway the document in the bucket gets deleted, if i do it the other way around and delete it from the shadow bucket it still appears in the gateway and the logs are silent.

Also i noticed now that turning it on for an existing bucket did not shadow all the existing document, just stuff that was created/updated after shadowing was turned on.

[jessliu]

I see, thank you. Instead of bucket shadowing what are you using instead?

[jnordberg]

We are using the gateway as db for our backend as well, over the admin interface, never talking directly to the couchbase server

[snej]

Our unit tests are infallible so there's no way this could be happening 😉 but I'll humor you and test this manually today using a real Couchbase Server bucket.

[snej]

Fixed. For some reason Couchbase Server sends Tap deletion messages with a nonzero expiration field, even for non-expiring documents. The shadower code was ignoring all events with a nonzero expiration. Made it only ignore them when it's an insertion/update event, not deletion. Verified that deletion from a real Couchbase Server bucket is propagated to the gateway database.