3 ms·
MySQL, for all its faults, actually handles this quite well. Generally speaking, assuming there aren't any major backwards-incompatibilities (which there haven'
by danudey 2y ago
MySQL, for all its faults, actually handles this quite well. Generally speaking, assuming there aren't any major backwards-incompatibilities (which there haven't often been in my experience), you can start up the old server in place of the new server and you're good to go. Some table-rebuilding can be done in-place if you need to do things like recreate indices, but _generally_ you're good to go from there.
For more complex deployments, cases of backwards-incompatibilities in the data structure, or where I had reason to rebuild many large tables, you set up a replication secondary, do pre-upgrade migrations (e.g. in the case of deprecated functionality), upgrade the secondary, do post-upgrade migrations (e.g. in the case of new functionality), and wait for replication to catch up 100%. Then, after sending traffic to it for a bit to ensure it works correctly, you swap the primary and secondary and do it again.