On 4/26/2019 6:14 AM, Sadiki Latty wrote:
What you're saying makes sense but is it achievable without downtime? i.e: Is
it achievable to change the replication factor to 2 as you suggest, and Solr
puts the sharded documents back together then replicate?
Just changing the replicationFactor parameter on the collection changes
nothing. It won't automatically add another replica unless you have
also configured autoscaling to do that. By default, replicationFactor
is just a parameter used when creating a collection.
You would have to add another replica for each shard. I don't see any
mention of your current Solr version or the version you are upgrading
to, so I will point you at the ADDREPLICA portion of the latest version
of the documentation, which is 7.7:
https://lucene.apache.org/solr/guide/7_7/collections-api.html#addreplica
Once you have multiple copies of your whole index running on different
servers, you can take one of the Solr servers down for an upgrade and
everything will still work with what's left.
Thanks,
Shawn
