monstache save timestamp not as expected when use change stream watching multiple collections

[neilchen12]

Hi rwynn.

when set change-stream-namespaces = ["db.member", "db.product"] and resume = true, If the synchronization of the member collection has a long delay(product collection is normal), if i insert one doc in product collection and the monstache save the timestamp in monstache collection, now timestamp recorded in the monstache collection is newer than member collection in oplog, this causes that the timestamp in the montache collection cannot be update when synchronizing the member collection oplog until the oplog timestamp is newer than the timestamp recorded in the montache collection(ic.hasNewEvents == false).

Is this expected behavior or is there something wrong with my configuration? Please help @rwynn

[rwynn]

Hi @neilchen12 Would you be able to try a different resume strategy? There is another that saves a separate resume token per change stream (per collection in your case) instead of a single timestamp. You can enable using

resume-strategy=1

https://rwynn.github.io/monstache-site/config/#resume-strategy

[neilchen12]

@rwynn thank you for your reply.

I tried resume token and it works, but sometimes i need to resume from a specified timestamp by resume-from-timestamp config( or directly modify the ts in the monstache collection), when use resume token, how should i do? the token._data doesn't seem to be modifiable.