When Confluence DC is in read only mode, CCMA does not work

Issue Summary

Confluence app vendors with DC compatible apps should decide how they choose to make their apps compatible with read only mode. This may be to disable the functionality of an app in read only mode so that an admin does not have to contend with an app writing data to the database.

In the case of CCMA, read only mode is often used by admins during a Server > Cloud migration, so CCMA should be fully functional during read only mode and continue to work.

Steps to Reproduce

1. Be running Confluence Data Center - (add a DC license to Confluence Server)
2. Put Confluence into read only mode - link
3. Start using CCMA

Expected Results

CCMA continues to work as usual

Actual Results

CCMA is not functional

Workaround

none