during the rollover - we notice the document count is already in the old index and when updating during that second the document count gets to the newly created indice as well. is there any way to prevent the duplication of data during the rollover ?
If I'm interpreting you correctly, you're seeing documents that are updated at the same time that rollover happens get written to the new index. Is that correct?
If so, in your update call, you need to specify the concrete index the original document is in, not the alias. When using rollover, any new documents should be written to the alias used for rollover, but any updates to existing documents should be done via the concrete alias they're already in.