I found this to be the most helpful: https://lists.apache.org/thread/g3m4nx3klfdrzhxvhtbqyj81sf6zj7k3 Plus I followed the recommendation to add the settings to SOLR_ZK_CREDS_AND_ACLS and not SOLR_OPTS in the solr.in.sh file: -Dzookeeper.client.secure=true -Dzookeeper.clientCnxnSocket=org.apache.zookeeper.ClientCnxnSocketNetty -Dzookeeper.ssl.keyStore.location=/path/to/zk-keystore.jks -Dzookeeper.ssl.keyStore.password=thepassword -Dzookeeper.ssl.trustStore.location=/path/to/zk-truststore.jks -Dzookeeper.ssl.trustStore.type=JKS -Dzookeeper.ssl.trustStore.password=thepassword"
-Matt
