$by_category projection issue

EventStoreDB
#1

Hi.

We are having a trouble with $by_category projection. The issue is that category that we are reading has no events that exist in original stream.

Here are the contents of a category: http://i.imgur.com/Yb70m33.png. There is event # 10, and then right after it event #13 from the same stream.

If I open stream itself: http://i.imgur.com/SNEHY5D.png, events are in the right order and go one after another as expected.

If I go to projections list and reset $by_category, events are appearing in the right order. I don’t really know the reason why such thing happen. What can I check to find out?

Thanks.

#2

Was there some kind of failure condition (e.g. a master takeover in a cluster) around the time this happened? I’ve not previously seen this, but it would be explained by a bug in recovering from a checkpoint (which is also causing other problems right now)

#3

We are running a single node. Unfortunately we can’t have stable reproduce steps.

#4

For the same DB while starting we have error message

[08084,16,11:36:34.905] The ‘$by_category’ projection faulted due to ‘An event emitted in recovery differ from the originally emitted event. Existing(’$>’, ‘C:49098978/P:49098467’). New(’$>’, ‘C:49098284/P:49097159’)’

But after projection restart issue it builds. We didn’t upgrade versions and always were running 3.0.1. Could this be related?

#5

Yes, that sounds related.

Are you able to supply us with a copy of your database for further analysis?

Thanks,

James

#6

I thought the issue was resolved by rerunning…