Although upgrading the APM network is generally a seamless process, this document presents a solution if certain errors occur.
After an APM migration, seeing some errors and the database does not start. What should I do?
APM 10.1 and Oracle 11g.
After migrating a perfectly APM working system with PostgreSQL to APM 10.1 and Oracle 11g, the EM works perfectly, but there is no access to the database.
Using INFO mode, we see these errors which are inconclusive:
10/12/15 04:34:31.700 PM EDT [ERROR] [main] [Manager] The EM failed to start. Error activating bean: com.wily.introscope.server.beans.apm.ApmServiceBean (com.wily.introscope.server.beans.apm.ApmServiceBean)
10/12/15 04:34:42.332 PM EDT [ERROR] [main] [Manager.AppMapSubsystem] APM Data model subsystem is unavailable so AppMap feature is not functional. Please check the DataBase connectivity or disable AppMap feature.
Logs in DEBUG mode shows these error messages:
10/12/15 04:34:14.106 PM EDT [DEBUG] [main] [org.hibernate.util.DTDEntityResolver] recognized hibernate namespace; attempting to resolve on classpath under org/hibernate/
10/12/15 04:34:28.477 PM EDT [DEBUG] [main] [org.hibernate.cfg.Configuration] hibernate.dialect=org.hibernate.dialect.Oracle10gDialect
10/13/15 04:37:06.673 PM EDT [ERROR] [main] [org.springframework.web.context.ContextLoader] Context initialization failed
Caused by: org.hibernate.HibernateException: Dialect class not found: org.hibernate.dialect.Oracle10gDialect
So this last line gives a hint that there is a problem trying to use the Oracle Dialect.
A closer look on the classpath shows org.hibernate.dialect.Oracle10gDialect. Replacing it with org.hibernate.dialect.OracleDialect resolves all these errors and EM with the Oracle DB starts and works faultlessly.