Akamai Diversity

The Akamai Blog

Best practices for running DNS caching servers

Your new DNS infrastructure is up and running! Here's what to watch for, how to monitor, and tips for patches and upgrades.

  • Run DNS process on server < 20% CPU
  • Maximize cache hit ratio by managing the memory cache value
  • Configure recursive Contexts to be at 10-15% of total available RC's during sustained operation
  • Distribute as much as possible
  • Keep servers as close as possible to subscribers
  • Use multiple operating systems and hardware types if your operations and deployment methods allow.
    • This is usually hard and could become cost prohibitive
      • Resources that understand multiple OS's
      • Multiple operating procedures for support
      • Varying deployment models
      • Expensive to operate
    • Performance metrics could vary based on the OS/hardware type

Monitoring: It is very important to keep track of every available system and software metric to keep your environment running at 99.999% uptime.

  • CPU utilization
  • MEM utilization
  • DISK utilization
  • I/O Subsystem stats
  • Interface statistics
  • Caching Server Process
  • Recursive context statistics
  • Queries per second
  • Top clients devices generating DNS queries
  • Top domains accessed

Patches and upgrades:

  • Validate patches/upgrades in a lab environment
  • Initially deploy patches/upgrades to a single server or a site and run for a period your operations team are comfortable with
  • Update any methods and procedures (M&Ps) for your operations team if new features and or functions have been added.