Description
SOLR-7245 added a retryOnConnLoss parameter to ZkController.ensureReplicaInLeaderInitiatedRecovery so that indexing threads do not hang during a partition on ZK operations. However, some of those changes were unintentionally reverted by SOLR-7336 in 5.2.
I found this while running Jepsen tests on 5.2.1 where a hung update managed to put a leader into a 'down' state (I'm still investigating and will open a separate issue about this problem).