Understanding DNS Record TTL in AWS Route 53

Key Concepts:

• TTL (Time To Live): A DNS record setting that tells clients how long to cache the DNS response. It is a crucial setting for managing DNS queries and their responses effectively.
• Purpose: Reduces the number of DNS queries made over time, as clients will cache the DNS response for the duration of the TTL.
• High TTL vs. Low TTL:
  • High TTL (e.g., 24 hours): Results in fewer DNS queries, reducing traffic and costs but may lead to outdated records being cached longer.
  • Low TTL (e.g., 60 seconds): Increases DNS queries, which can increase costs but allows for quicker updates to DNS records.

TTL Management Strategy:

1. Pre-Update: Before changing a DNS record, reduce the TTL (e.g., to 60 seconds) to ensure clients frequently update their cache.
2. Update Record: Make the necessary changes to the DNS record.
3. Post-Update: After ensuring all clients have the updated record, increase the TTL again to reduce the frequency of DNS queries.