Stream Sourcing : Limit of the number of transforms rules that can be configured as part of Stream Sources->SubjectTransforms

[arunsmenon88]

Hello NATS team,
Is there a limit to the SubjectTransforms that can be configured as part of the StreamConfig.Source.[]SubjectTransforms ?

As a test case, i tried to configure upto 1000 transform rules as part of my StreamSource->SubjectTransforms (using nats.go) and i could observe that the stream create or stream update operation takes more than 30 seconds to complete.

Is there any guidance on how many transform rules can be configured and how it would impact the performance of nats-server?

[ripienaar]

Technical limits aside imo more than 10 would suggest a design problem in how your subject layout is put together.

Why would you need so many?

[NicholasTNG]

Not OP, but we have something similar. We are using the subject transformations to dynamically limit the sync of messages in a stream across a leaf node connections (we don't want to sync everything for bandwidth reasons). We have issues with our update operations timeouting and further all subject transformations are in the Nats-Stream-Source header of sourced messages. This gives problems with headers getting to big.