Get stream length

EventStoreDB
1

Hi,

Is there a built in way of getting stream length, which takes into consideration that streams may have been truncated e.g old items expired?

At first I tried using the C# API with ReadStreamEventsForwardAsync (from event 0) and then using LastEventNumber - FromEventNumber with the slice result, but you have to know what the first actual event number is to get this to work, otherwise the slice reports that FromEventNumber is 0 even if the stream has been truncated.

For reference, I would like to know what stream length is for monitoring purposes e.g. length of parked message streams.

Thanks, Tim.

2

Stream metadata will have $tb set for truncated streams (unless max age/count)

3

Hi Greg,

Sounds like I can optimise for the case where $tb is available, and use something like a binary search for the maxAge case. It's not time critical so should be fine.

Thanks, Tim.

4

Just read the first event and the last event :slight_smile:

5

Hi Greg,

Reading the first event (event 0) using ReadStreamEventsForwardAsync yields an empty slice for streams that have been truncated. I fear I am missing something obvious here 're. the API.

I would of course optimise for streams that have not been truncated :slight_smile:

Thanks.

Just read the first event and the last event :slight_smile:

6

Do you want the length of the stream as it would have been it if were not truncated? or the number of events in it?

7

The number of events remaining in the stream i.e. after truncation.

8

https://github.com/EventStore/EventStore/blob/dev/src/EventStore.ClientAPI/EventStoreCatchUpSubscription.cs#L392

What are you getting here?

9

Can take a look later, cheers.