Guide me to configure ELK open source version on premises as extension nodes of ECE and transfer data by excluding ECE nodes from holding data.
As far I know that is not possible..
In general, all nodes an elastic cluster need to be / required to be at the same license level..
ANY workaround / hack To try to get that working most likely violates the license agreement.
If you are a paying customer of ECE, you should contact your account team and ask them these questions directly.
CCS/ CCR between clusters, requires all clusters be at the same license level.
We will not be comment anymore on that in the public forum.
Now all that said, you could build a completely separate elastic basic cluster and use something like logstash to transfer to/ migrate the data between the two clusters, that is completely valid...