Keda: [Scaler] Azure CosmosDB

[jeffhollan]

Scale on the Azure CosmosDB change feed. Would require Go SDK support most likely, or work to make scalers extensible.

[jeffhollan]

Chatted with the CosmosDB team. The Go SDK doesn't currently have support for the change feed, but they are willing to work with us and help write the logic that would be needed to check the leases collection and know how much remaining work is there in a Go variation of the code

[edrevo]

@jeffhollan, do you know if there's any update of this? I'd definitely be interested in a CosmosDB change-feed scaler

[lgmorand]

same here. customers are looking for it

[tomkerkhove]

Paging @jeffhollan to see if we can implement this.

@lgmorand @edrevo What are the scenarios you are looking at? Just change-feed or scale on other metrics/scenarios as well?

[edrevo]

From my side, change feed is enough

[lgmorand]

I have two customers with cosmosdb as the output of databricks and functions in AKS to consume them so changefeed should be perfectly fitted

[tomkerkhove]

This should be feasible, but we need a Go SDK / REST API interface which is probably not available yet.

@jeffhollan can you follow-up on this please? An alternative approach is to evaluate an external scaler which handles through .NET Core or so.

[bsstahl]

Would it be possible to get an update on this? I know it depends on other work outside of the scope of this project but it is also likely to become a blocking issue for me and my company very soon. Have we gotten an ETA on the Cosmos SDK work or REST API that is blocking this issue? Scaling based on the change feed is all I'd need at this point.

[tomkerkhove]

I'll try to get some info

[abhirockzz]

@tomkerkhove @jeffhollan It maybe possible to implement this using a combination of External Scaler and Change Feed Estimator.

[tomkerkhove]

This is coming through an external scaler that you can find here: https://github.com/kedacore/keda-external-scaler-azure-cosmos-db

It is still being developed though.