CODEWITHSUNDEEP
amazon-ec2dnsload-balancing
pjf
pjf

Reputation: 193

Amazon ec2, ELB and DNS

I am trying to come up with a solution to my problem and I am sure it would be possible using AWS but I am not sure which product would be required.

Problem: Load balancing DNS with AWS.

I host a DNS server that has a lot of simple records. This server runs DNS on port 53. I am looking to load balance the connections to port 53 across multiple instances.

When I look at amazons ELBs it has HTTP, HTTPs, SSL and TCP but There is no option for UDP or DNS. How can I achieve this?

Is this a feature of Route 53 that I am missing. Route 53 hosts my domain records but this is a separate system. I cannot add 500,000 records to Route 53 or is that what I would need to do?

Upvotes: 0

Views: 942

Answers (2)

Michael - sqlbot
Michael - sqlbot

Reputation: 178956

I'm not seeing a reason why you'd need a load balancer for DNS servers. Serving up DNS is pretty much self-load-balancing... that's why a domain typically has at least two authoritative DNS servers. When you configure your domain (with the registrar) the DNS servers are listed in an order, but they are not used in order. You should typically be able to declare multiple DNS servers for the domain and expect each one to receive an approximately even balance of traffic.

If the DNS server you describe is working from delegated subdomains, the same thing should hold true -- delegate the subdomains to multiple servers with multiple NS records from within Route 53.

Because DNS is inherently designed such that once a resolver server, looking up your DNS records on behalf of clients, gets an answer from one of your servers, it will cache that answer until the time-to-live (TTL) expires, so, on the case of only 2 DNS servers, with one server offline, the number of attempted lookups hitting the failed server, timing out, and retrying the other server would be far less than half the total number of lookups attempted, because resolvers would already be serving up their own cached replies to popular queries.

Alternatively, you can programmatically create records in Route 53 through the various APIs... as opposed to typing in thousands of records by hand. The "maximum number of records" limit in Route 53 is 10,000 per zone by default, but there is an established process for requesting that this limit be raised.

http://docs.aws.amazon.com/Route53/latest/DeveloperGuide/DNSLimitations.html

Upvotes: 1

slayedbylucifer
slayedbylucifer

Reputation: 23492

There is no out-of-the-box DNS load balancing feature available in AWS at the moment.

Route 53 does provide DNS fail-over but it does not do DNS load balancing.

for ELB, what you have already mentioned your post stands true.

Upvotes: 0

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