- Is it being used as long-term storage for the Workflow data?
( Whenever Workflow data is updated, Temporal sends a POST to Elasticsearch so as to update the ES data )
No, workflow data is never stored in ES. It only stores so-called “visibility records” which are used to list workflows based on various properties we call “search attributes”.
- Is a Kafka installation needed for using ES ? ( An old post seems to be suggesting that it is needed: How to set up ElasticSearch? - #4 by samar )
It was needed some time ago. The recent releases of Temporal don’t use Kafka for anything.
- Our interest is mainly in the long-term storage of our business objects that will get updated as the result of various workflows. ( Temporal related data and the ability to debug Temporal Workflows is not really important at this point )… is it better if we maintain our business data independent of Temporal-ES integration?
Yes, we recommend storing this business data independently from ES. Another option is to have an always open workflow that maintains that particular entity data. It is hard to give a concrete recommendation without knowing the specifics of your use case.