Replication not replicating every document

[panuhorsmalahti]

I first thought this was a CouchDB issue, but now I'm suspecting it's npm specific.

I've documented the issue here:
https://issues.apache.org/jira/browse/COUCHDB-2822

I'm replicating the NPM's skimdb from https://skimdb.npmjs.com/registry/ to my own, private database. The replication has been working for about a year, but it was timed out for a month. Now if I start the replication again, it's successfully picking up all the new changes to the database, but not replicating any (or almost none?) of the changes for the duration of the downtime of the replication.

The issue might be caused by the target document (in this example the id is "nan") having "_rev": "102-e83ff1aefa1bcd7165cc9e8b7e14532d" while the source document has "_rev": "18-a3159727cf84daf13992d181d25e83de" even though the source document should contain more updates than the target document. I don't understand why the target document has such a high revision number. I wonder if npm changed the revision numbers at some point.

[panuhorsmalahti]

Hmm, I remember that we used the full fat registry at some point in the past, and switched to the skim db.

I also noticed that e.g. the "nan" package only has 18 revisions here:
https://skimdb.npmjs.com/registry/nan?revs=true&revs_info=true

But it should have about 51 revisions due to having 51 releases.

I wonder if the real cause of this replication issue is that the skim db was not "cleanly" replicated from the full fat registry, thus having different revision history? EDIT: But apparently we switched cleanly from the full fat registry to the skimdb, not simply changing the replicator, so this is probably not the reason.