Migrating a 50GB WooCommerce site with zero downtime — the runbook we use

A recent WooCommerce migration: 50 GB of data, 480,000 products, 14 years of order history, moved from a creaking single-server VPS onto a properly-architected setup. Total customer-facing downtime: 38 seconds. The trick isn't speed — it's setting up MySQL replication to the new host while the old host is still taking orders, so cutover replays only the last few seconds of writes.

The cutover script — the 38-second part

ssh source "wp maintenance-mode activate"
sleep 60                                          # drain in-flight checkouts
ssh dest "mysql -e 'STOP SLAVE; RESET SLAVE ALL;'"
rsync -avz --delete source:uploads/ dest:uploads/
ssh dest "wp search-replace 'old-domain.com' 'new-domain.com' --all-tables --skip-columns=guid"
curl -X PATCH ".../dns_records/$ID" -d '{"content":"<new-ip>"}'
ssh dest "wp maintenance-mode deactivate"

The rsync is fast because the bulk copy ran nightly for a week prior. The DB is fast because replication has been catching up all along.

The full write-up covers:

• Why mysqldump-and-import is wrong for sites this size
• Setting up cross-host MySQL replication for the bulk-copy phase
• Character set + collation traps (emoji in product names will bite you)
• The dry-run cutover against staging — what to test before the real one
• Payment gateway webhook handling during cutover
• The 72-hour reverse-replication safety net for hot rollback

We've run this playbook on every meaningful WooCommerce migration in the past two years. Reach out if you're staring down one.