Ability to run Confluence in 'Read-Only' mode

It would be nice if Confluence could run in a read-only mode, selectable through the administrative console.

This would make it easy to disable modifying pages when read access should still be possible. Currently, when exporting in preparation for an upgrade we have to involve network operations to disable access to Confluence for the general public but allow access to the administrator.

Additionally, our MySQL cluster failed over to the read-only node today. Every few minutes Confluence stopped working due to cluster safety issues, even though we're not operating in a cluster. We gave up on rebooting until the read-write node recovered.