$by_correlation_id projection

EventStoreDB
1

Hi,

I tried to test $by_correlation_id projection, but no $bc streams are available while projection enabled.

I enabled the projection and emitted some events with “$correlationId”: “332d7902-f9ca-4565-a069-2002b55ffc44”, but the stream “$bc-332d7902-f9ca-4565-a069-2002b55ffc44” doesnt exists. In projection detail is right number of processed events, but the projection doesnt create any new streams.

Am I doing something wrong?

Thanks,

Jakub Koci

2

Hi,

Is this on ES 5 or 4? Did you put the field in the event or the
metadata? (needs to be in metadata AFAICT)

/Rickard

3

Hi,

yes it is on Event Store 5.0.0.0, running in docker. I have correlationId in metadata with same key like in the projection:

{"$correlationId": “332d7902-f9ca-4565-a069-2002b55ffc44” }

{“correlationIdProperty”:"$correlationId"}

When I emit new event the processed events number in projection is increased so everything looks working, but no “$bc-” stream appear.

Thanks

út 26. 2. 2019 v 11:19 odesílatel Rickard Öberg [email protected] napsal:

4

So, just to double check:
In config you have:
RunProjections: System

You have enabled the projection:
curl -i -X POST
"http://localhost:2113/projection/%24by_correlation_id/command/enable"
-H "accept:application/json" -H "Content-Length:0" -u admin:changeit

You can see it running at:
http://localhost:2113/web/index.html#/projections

But it doesn't show up at:
http://localhost:2113/web/index.html#/streams

Is that correct?

/Rickard

5

Correct. Im running also $by_category projection and it works without any problems…

út 26. 2. 2019 v 15:13 odesílatel Rickard Öberg [email protected] napsal:

6

I found the problem…

I am using ES HTTP API client, which sends body with escaped quotes in data and metadata. So the projection can not propably identify correlationIdProperty:

[

{

“eventId”: “someId”,

“eventType”: “someType”,

“data”: “{“aggragateId”:“95799ea1-aab1-4b20-aadc-d7cfff6fd4c3”}”,

“metadata”: “{”$correlationId":“fbacdd2b-88a3-4b5f-995b-131ff187f660”}"

}

]

If I send it like standart json, projection works right:

[

{

“eventId”: “someId”,

“eventType”: “someType”,

“data”: {“aggragateId”:“95799ea1-aab1-4b20-aadc-d7cfff6fd4c3”},

“metadata”: {"$correlationId":“fbacdd2b-88a3-4b5f-995b-131ff187f660”}

}

]

ES accept both formats and events are identical in the ES, but the first format its not processed by $bc projection, which is little bit confusing.

út 26. 2. 2019 v 15:20 odesílatel Jakub Koci [email protected] napsal:

7

Hey folks,

Sorry for the dumb question, but how can you see the Visualisation of the correlationId using public Docker image?
Do I need to get “Enterprise” for that or is the Enterprise for production only (not sure how the licensing works)?

Cheers,
D.

8

Hey there,

Yup, it’s just for commercial users I’m afraid.

Chris

9

Thanks Chris.

Maybe you know if there is some documentation on this publicly available
(can't seem to see it, and event change-log screenshot is a 404)?

10

You can find a little here - ​https://github.com/EventStore/documentation/pull/333

But it’s not finished, and I’m not sure useful it is to you without having the featue.

Chris