Route 53 Flashcards
What is Route 53?
R53 is a managed DNS
What is DNS?
DNS is a collection of rules and records which helps clients understand how to reach a server through URLs.
The most common records are?
- A: URL to IPv4
- AAAA: URL to IPv6
- CNAME: URL to URL
- Alias: URL to AWS resource.
R53 has what features?
- Load balancing (through DNS – also called client load balancing)
- Health checks (although limited…)
- Routing policy: simple, failover, geolocation, latency, weighted, multi value
How is R53 priced?
• You pay $0.50 per month per hosted zone
What is the different DNS Records TTL (Time to Live)
Low TTL (60s)
More traffic on DNS
• Records are outdated for less time
• Easy to change record
High TTL (24 hr)
Less traffic on DNS
• Possibly outdated records
Is TTL mandatory for each DNS record?
YES
CNAME works for root domains?
False
Alias works for Root and Non root domains?
True
What’s a simple routing policy?
Maps a domain to one URL
• Use when you need to redirect to a single resource
• You can’t attach health checks to simple routing policy
What’s a weighted routing policy? And their uses?
- Control the % of the requests that go to specific endpoint
- Helpful to test 1% of traffic on new app version for example
- Helpful to split traffic between two regions
- Can be associated with Health Checks
What’s Latency Routing Policy
Redirect to the server that has the least latency close to us
• Super helpful when latency of users is a priority
• Latency is evaluated in terms of user to designated AWS Region
• Germany may be directed to the US (if that’s the lowest latency)
Health checks marked unhealthy after how many unhealthy responses? What’s the default health check interval?
3, 30s
About how many health checkers will check the endpoint health?
15
What kinds of health checks can you have? SSL verification?
Can have HTTP,TCP and HTTPS health checks (no SSL verification)
