An aside: Remember that the leader is a replica too, so your numbers are off & confusing. "single shard with no replicas" -- I guessed what you mean but surprised to hear a misuse of SolrCloud lingo from you. AFAICT, leadership isn't even pertinent to your inquiry either.
On Wed, Mar 11, 2026 at 5:38 PM David Eric Pugh via dev <[email protected]> wrote: > Hey all, I wanted to get some feedback from you'all on a recent usecase I > was asked about. I suspect the answer will be "Use Solr Operator", but > here goes! > I have an environment where I have 5 or so single shard collections. > Much of the time I run just a single node and each collection is a single > shard with no replicas. Sometimes, to support load, I'll add another node > or two. Then I'll add replicas so cover the new nodes, 1 per node. So > with three nodes, I have one leader and two replicas. Add two more nodes, > move to one leader and four replicas. > However, when I remove a node by shutting it down, then Zookeeper never > get's notified about this, and so the replica is listed as down, and the > node is listed as down in red in the UI. When it isn't really red, it's > just we don't need it for now, and it's not coming back. > I'd like to just declare "For this collection, I want one replica per node > based on however many nodes are current". I don't want to call the > various commands myself to add replicas and or remove then as nodes are > added or removed. And I don't want to call various apis or other complex > things when I add or remove a node, I just want bin/solr stop and bin/solr > start to be run ;-). > I think this is what Replica Placement Plugins were for maybe? Could I > have a Replica Placement strategy that when ZK sees a new node added, then > creates a new replica on it, and vice versa, when a node goes away, it just > removes that replica instead of treating it as "down"? > Thoughts? > Eric >
