Blue/Green Deployment to 7.7

Hi,

I'm running a 3 node cluster running 1 shard 2 replica for most indexes. Is it possible to carry out a Blue/Green deployment type upgrade to Elasticsearch whereby I shutdown a node and bring up a brand new node on 7.7 which then replicates the data from the existing 2? then repeat this step until all 3 nodes are upgraded?

If so will i need to carry out any of the pre-work around sync flush, disable shard allocation etc...

Thanks

Yes it is!

will i need to carry out any of the pre-work around sync flush, disable shard allocation or can I treat it like a failed node and just shutdown and bring up a new node?

The cleanest way is to add the new node, then use allocation filtering to exclude one of the old version nodes, wait for it to be empty, then remove. Repeat.

Given you have 2 replicas, you can probably just "hard" stop one node and the cluster will be ok. Then add the new one and let it rebalance. But the first method is ultimately safer.

Great thanks