Hi, we are currently trying to test the KYLIN-3552 feature to rely directly on Mysql for data source instead of Hive.
(we tried as much as possible to add correct info in kylin.properties, add mysql jdbc drivers, create mysql.xml in ./conf/datasources ... as mentioned in https://github.com/apache/kylin/pull/327/files ) the error we entountered is ( excerpt from kylin.log ) : 2019-01-14 09:48:16,223 WARN [http-bio-7070-exec-2] extensible.JdbcSource:50 : DataSource cannot be connected. This may not be required in a MapReduce job. java.lang.LinkageError: loader constraint violation: loader (instance of sun/misc/Launcher$AppClassLoader) previously initiated loading for a different type with name "org/apache/kylin/common/KylinConfig" at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:763) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) at java.net.URLClassLoader.access$100(URLClassLoader.java:73) at java.net.URLClassLoader$1.run(URLClassLoader.java:368) at java.net.URLClassLoader$1.run(URLClassLoader.java:362) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:361) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) at org.apache.kylin.sdk.datasource.framework.SourceConnectorFactory.getJdbcConnector(SourceConnectorFactory.java:27) with further trace : 2019-01-14 09:48:16,229 ERROR [http-bio-7070-exec-2] controller.TableController:197 : java.lang.NullPointerException at org.apache.kylin.source.jdbc.extensible.JdbcExplorer.listDatabases(JdbcExplorer.java:58) at org.apache.kylin.rest.service.TableService.getSourceDbNames(TableService.java:280) at org.apache.kylin.rest.controller.TableController.showHiveDatabases(TableController.java:195) do you have any idea ? Is there a User guide ?
