DNS resolution failure in high load environment with SERVFAIL and "out of memory/success" in the log

Issue

• "SERVFAIL" message once domain ttl is expired.
  For example,

  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3504
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0
  
  ;; QUESTION SECTION:
  ;www.example.com.INA
  
  ;; ANSWER SECTION:
  www.example.com.3374INCNAMEt.www.example.com.edgesuite.net.
  www.example.com.edgesuite.net. 74 INCNAMEa1189.r.akamai.net.
  a1189.r.akamai.net. 1    IN  A  115.112.3.13
  a1189.r.akamai.net. 1   IN  A  115.112.3.6 <---- TTL is 1s 
  
  ;; Query time: 0 msec
  ;; SERVER: 10.132.60.18#53(10.132.60.18)
  ;; WHEN: Fri Apr 24 21:15:15 2015
  ;; MSG SIZE  rcvd: 137
  
  
  $ date +%T; dig www.example.com
  21:15:16
  
  ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.30.rc1.el6_6.1 <<>> www.example.com
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 44786 <---------- SERVFAIL. 
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
  
  ;; QUESTION SECTION:
  ;www.example.com.INA
  
  ;; Query time: 0 msec
  ;; SERVER: 10.132.60.18#53(10.132.60.18)
  ;; WHEN: Fri Apr 24 21:15:16 2015
  ;; MSG SIZE  rcvd: 33