Merge branch 'main' of https://github.com/MicrosoftDocs/azure-docs-pr into mrb_08_21_2024_enhancements

Author: mrbullwinkle

articles/hdinsight/hdinsight-upgrade-cluster.md

@@ -59,6 +59,7 @@ As mentioned above, Microsoft recommends that HDInsight clusters be regularly mi
      * **Multiple workloads on the same cluster**. In HDInsight 4.0, the Hive Warehouse Connector needs separate clusters for Spark and Interactive Query workloads. [Follow these steps to set up both clusters in Azure HDInsight](interactive-query/apache-hive-warehouse-connector.md). Similarly, integrating [Spark with HBASE](hdinsight-using-spark-query-hbase.md) requires two  different clusters.
      * **Custom Ambari DB password changed**. The Ambari DB password is set during cluster creation and there's no current mechanism to update it. If a customer deploys the cluster with a [custom Ambari DB](hdinsight-custom-ambari-db.md), they have the ability to change the DB password on the SQL DB; however, there's no way to update this password for a running HDInsight cluster.
      * **Modifying HDInsight Load Balancers**. The HDInsight load balancers that are automatically deployed for Ambari and SSH access **should not** be modified or deleted. If you modify the HDInsight load balancer(s) and it breaks the cluster functionality, you will be advised to redeploy the cluster.
+     * **Reusing Ranger 4.X Databases in 5.X**. HDInsight 5.1 has [Apache Ranger version 2.3.0](https://cwiki.apache.org/confluence/display/RANGER/Apache+Ranger+2.3.0+-+Release+Notes) which is major version upgrade from 1.2.0 in HDInsight 4.X clusters. Reuse of an HDInsight 4.X Ranger database in HDInsight 5.1 would prevent the Ranger service from starting due to differences in the DB schema. You would need to create an empty Ranger database to successfully deploy HDInsight 5.1 ESP clusters.
 
 ## Next steps