Hi, I think there is a bug on the getUserList method when the Shiro realm is a JdbcRealm. A connection is borrowed from the connection pool but it's never close:
https://github.com/apache/zeppelin/blob/master/zeppelin-server/src/main/java/org/apache/zeppelin/rest/GetUserList.java#L241 Kind regards, Luis Angel Vicente Sanchez zeppelin-us...@bigcente.ch
