Choosing TTL values involves trade-offs.
Long TTLs (hours to days):
- Reduce load on authoritative servers
- Faster lookups for users (cached locally)
- Slow propagation when you make changes
Short TTLs (minutes):
- Changes propagate quickly
- More queries hit your servers
- Useful before planned changes
Before migrating servers, lower TTLs to minutes. After migration completes, raise them back to normal.