In about a week, I have to update several production sites hosted in AcquiaCloud environments to 8.5.3. All of these sites receive frequent real-time DB writes from user-submitted content. I can request that the site be put into maintenance mode to limit user interactions with the DB, but I cannot, under any circumstance, lose any data whatsoever during the process of upgrading production to 8.5.3 from 8.4.3.
There are, as you know, several db schema changes/updates between the two versions and I am using modules in these sites that frequently alter the schemata between releases; i.e. Multiversion/Revisions, Workspaces, Workflow Moderation, etc.
What is the best practice to pull down my production database, reconcile it and get it working against my dev 8.5.3 environment, and safely send it back up to prod? Getting 8.5.3 working with the current schema of the production 8.4.3 site took a ridiculous amount of debugging, troubleshooting, and work to get a mostly-functional site. I feel like I'm missing something here. Can anyone offer advice on reconciling my two environment databases? Thanks in advance, any help is appreciated!