Search Services Release Notes for 1.8.16-GA

This is technically a code-level (not API level) breaking change, since references to ZooKeeper now point to SolrZkClient.

However, it likely will not affect most clients, since most will not have overridden logic in DefaultZooKeeperDistributedLockService or ReentrantDistributedZookeeperLock.

For those who have, migration is very simple, as SolrZkClient contains almost all the same methods as ZooKeeper albeit with slight differences in arguments (like the addition of a boolean retryOnConnLoss parameter). Furthermore, SolrZkClient does expose its internal ZooKeeper instance with a getter if direct use of it is still required (though it should be used with care, as it may be recycled as described above).