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https://issues.apache.org/jira/browse/SOLR-8619?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15122882#comment-15122882
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Erick Erickson commented on SOLR-8619:
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Perhaps a new state? "new"? "never_syncd"? "not_eligible_for_leader_election"? 
Whatever. Point is just a flag saying "I don't care what else you do, I 
shouldn't be leader yet".

Still, you'd have to reconcile such a state with collection creation, but that 
doesn't seem like a big deal.

> A new replica should not become leader when all current replicas are down as 
> it leads to data loss
> --------------------------------------------------------------------------------------------------
>
>                 Key: SOLR-8619
>                 URL: https://issues.apache.org/jira/browse/SOLR-8619
>             Project: Solr
>          Issue Type: Bug
>            Reporter: Anshum Gupta
>
> Here's what I'm talking about:
> * Start a 2 node solrcloud cluster
> * Create a 1 shard/1 replica collection
> * Add documents
> * Shut down the node that has the only active shard
> * ADDREPLICA for the shard/collection, so Solr would attempt to add a new 
> replica on the other node
> * Solr waits for a while before this replica becomes an active leader.
> * Index a few new docs
> * Bring up the old node
> * The replica comes up, with it's old index and then syncs to only contain 
> the docs from the new leader.
> All old documents are lost in this case
> Here are a few things that might work here:
> 1. Reject an ADDREPLICA call if all current replicas for the shard are down. 
> Considering the new replica can not sync from anyone, it doesn't make sense 
> for this replica to even come up
> 2. The replica shouldn't become active/leader unless either it was the last 
> known leader or active before it went into recovering state
> unless there are no other replicas in the clusterstate.
> This might very well be related to SOLR-8173 but we should add a check to 
> ADDREPLICA as well.



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