1 files changed, 22 insertions, 3 deletions
diff --git a/lib/gitlab/database/load_balancing/resolver.rb b/lib/gitlab/database/load_balancing/resolver.rb
index a291080cc3d..3e3998cae92 100644
--- a/lib/gitlab/database/load_balancing/resolver.rb
+++ b/lib/gitlab/database/load_balancing/resolver.rb
@@ -7,8 +7,21 @@ module Gitlab
   module Database
     module LoadBalancing
       class Resolver
+        FAR_FUTURE_TTL = 100.years.from_now
+
         UnresolvableNameserverError = Class.new(StandardError)
 
+        Response = Class.new do
+          attr_reader :address, :ttl
+
+          def initialize(address:, ttl:)
+            raise ArgumentError unless ttl.present? && address.present?
+
+            @address = address
+            @ttl = ttl
+          end
+        end
+
         def initialize(nameserver)
           @nameserver = nameserver
         end
@@ -28,13 +41,14 @@ module Gitlab
         private
 
         def ip_address
-          IPAddr.new(@nameserver)
+          # IP addresses are valid forever
+          Response.new(address: IPAddr.new(@nameserver), ttl: FAR_FUTURE_TTL)
         rescue IPAddr::InvalidAddressError
         end
 
         def ip_address_from_hosts_file
           ip = Resolv::Hosts.new.getaddress(@nameserver)
-          IPAddr.new(ip)
+          Response.new(address: IPAddr.new(ip), ttl: FAR_FUTURE_TTL)
         rescue Resolv::ResolvError
         end
 
@@ -42,7 +56,12 @@ module Gitlab
           answer = Net::DNS::Resolver.start(@nameserver, Net::DNS::A).answer
           return if answer.empty?
 
-          answer.first.address
+          raw_response = answer.first
+
+          # Defaults to 30 seconds if there is no TTL present
+          ttl_in_seconds = raw_response.ttl.presence || 30
+
+          Response.new(address: answer.first.address, ttl: ttl_in_seconds.seconds.from_now)
         rescue Net::DNS::Resolver::NoResponseError
           raise UnresolvableNameserverError, "no response from DNS server(s)"
         end