Determine timestamp of replication of documents during live sync in Cloudant

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Right now I have transaction syncs with clients that go offline and online frequently. This means that creation of a transaction document (when it goes into pouch) doesn't align with the point that it is entered into Couch.

Is there a way for me to tag these documents with a timestamp on confirmation of replication? I see there are advanced replication schedulers but the completed flag does not apply to live replication which is what we are using.

I have tried tagging the document before syncing it, but this doesn't account for issues of network delay or backend delay of replication. It simply is the time I started the sync of that document, there's no promise that it arrived at that point in CouchDB.

cloudant pouchdb couchdb
1 Answers

You would need to use an add-on like spiegel (using on_change documents to call back to an update function) or another (pouchdb?) client to observe the changes feed and add the timestamp of when it was available to that client from the couchdb (which might be a little delayed).

Such a client would be in danger of creating an infinite loop as @Flimzy indicated in the comments, unless it uses a rule to not re-update docs with existing timestamps so that it does not write when it is re-triggered by itself and therefore stops retriggering itself. Spiegel has support for such a rule and/or stopping an infinite loop could be part of an update function.

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