We can't communicate with your server error on CCMA 3.2.6 when connecting to Oracle DB

Issue Summary

We can't communicate with your server error on CCMA version 3.2.6. Issue has been reproduced when connecting to an Oracle database

Steps to Reproduce

• Create migration on CCMA 3.2.6
• Save and run

Expected Results

• Migration runs

Actual Results

• Page refreshes and migration cannot start

The below exception is thrown in the atlassian-confluence.log file:

java.sql.SQLRecoverableException: Closed Connection

Workaround

• Downgrade CCMA to previous version.
• Uninstall Confluence Migration Assistant 3.2.6 and upload version 3.2.5
• Old version of Confluence Migration Assistant can be found here:
  https://marketplace.atlassian.com/apps/1219672/confluence-cloud-migration-assistant/version-history
• In Confluence server, go to ${CONFLUENCE_URL}/admin/darkfeatures.action
• Add the following feature:
  • migration-assistant.disable.app-outdated-check
• Clear your cache if needed and then try running the migration again.

Notes

After setting up Confluence 7.13.1 with Oracle 12c R2, the issue could not be replicated. It's possible this is caused by a database configuration issue or another performance issue.