I had a quick question on CCR feature which is now GA in 6.7, based on the documentations & presentations available, we can now create two different clusters in two different regions, so going by this ideology.
If I setup a cluster of 3 masters & 3 data nodes in Azure (US-East) region which I would term as a Leader cluster (assuming all the indices in this cluster are leaders), another cluster of 3 masters & 3 data nodes in Azure (US-West) which I would term as follower.
Now that everything is setup & the follower is accurately replicating the leader, I am able to perform index / search operations on the leader.
Due to some reason the region holding my leader cluster goes out, I would be left will the following DR mechanism.
- Update all the indices in the follower cluster to stop following using the "unfollow" API, as this is an index level API I would have to run this against all the indices in the cluster.
- Using the "unfollow" API now makes this cluster a "leader" eligible cluster, which means I can send indexing requests to this cluster.
- Since the "unfollow" API has a drawback "Converting a follower index to a regular index is an irreversible operation.", when my orignal leader region is up, I am left with no other option but to discard everything indexed on that cluster & setup a new cluster altogether which would now be a follower cluster - per documentation "Currently cross-cluster replication does not support converting an existing regular index to a follower index".
Could you please let me know how / what would be the appropriate action in-case of the above scenario using CCR, or are there any planned features which could fill the gap mentioned above.