Introduction:
Upgrading Oracle WebLogic Server from version 12c to 14c is essential for leveraging the latest capabilities, enhancing security, and aligning with modern cloud-based architectures. This guide outlines the key reasons, challenges, and steps for a successful upgrade.
Why Upgrade to WebLogic 14c:
Extended Support: Older WebLogic 12c versions are under limited or no Oracle support.
Java 11 Compatibility: WebLogic 14c supports Java SE 11, a requirement for many modern applications.
Cloud Readiness: Improved Kubernetes and Docker integration for microservices architecture.
Enhanced Security: Stronger encryption and updated security patches.
Challenges in Upgrading:
Domain Compatibility: Existing domain schema needs reconfiguration for 14c.
Deprecated Features: Some WLST commands and APIs are no longer supported.
Application Compatibility: Applications using deprecated classes require updates.
Custom Scripts: Startup/shutdown scripts and Node Manager configurations need adjustments.
Steps to Upgrade WebLogic from 12c to 14c:
1. Backup Existing Environment
Take backups of domains, configuration files (config.xml, JDBC, JMS), and applications.
Backup database schemas linked with WebLogic resources.
2. Install WebLogic 14c
Download and install WebLogic 14c in a new directory.
Apply latest Oracle patches (PSU).
3. Upgrade the Domain
Use WLST to read and upgrade the domain:
readDomain(‘/u01/oracle/domains/mydomain’)
updateDomain()
closeDomain()
Run reconfig.sh if required for domain schema updates.
4. Update Custom Scripts and Node Manager
Update JAVA_HOME and MW_HOME paths in scripts.
Reconfigure Node Manager to point to new WebLogic installation.
5. Validate JDBC & JMS Resources
Replace deprecated JDBC drivers.
Test connection pools and JMS modules.
6. Test Applications
Deploy applications in the upgraded environment.
Validate logs for errors and warnings.
Rollback Plan
Stop WebLogic 14c and restore backup of WebLogic 12c.
Revert database changes if any.
Conclusion:
Upgrading to WebLogic 14c ensures compatibility with modern technologies, improved performance, and security compliance. Following a structured approach helps avoid risks during migration.
