Minimum size for in-sync replicas (allocation IDs)

OpenDistro
1

Hi,

I was reading many articles online on how the replication protocol works in OpenSearch (Relevant to ES as most articles on that).

I was wondering if it’s possible in OpenSearch to define the minimum size for in-sync replicas. I’m aware of the index.write.wait_for_active_shards feature, which will wait for say 2 / 3 active shards before continuing with writing to replicas, yet it’s not enforced - it those nodes failed the operation, it will still ack the write, although written say only to the primary.

My questions are:

  1. Is it possible to define a minimum number for the in-sync and if below per write, fail?
  2. What was the motivation for that decision in the protocol. It stands in contrast with other systems like Kafka, Cassandra, M3.

Would love any input on that,

Thanks!

Asaf