I'm exploring options around keeping my Drupal 7 sites working for anonymous visitors while a database server is being upgraded. The site is already fronted by Cloudflare - but their always on tech is a little hit and miss.
I'd like to understand more about when the database is queried when using the memcache module. My other choice is to use the AutoSlave module and setup a master - slave replication - but if I can get a performance boost from memcache and a little resilience added in - I'd maybe prefer that route.
I'm hoping that the page cache will remain relevant enough to perform the database upgrade. What are the rules around the memcache content going stale?