Finish Reverse DNS lookup

[thorncorona]

Description

DNS lookup code.

InetAddress.getByName(ip).getCanonicalHostName();

Java's native implementation is very slow.

• 15s-20s to fail resolution
• 30-100ms to successfully resolve.

Out of sites

[
  'google.com',
  'reddit.com',
  'nytimes.com',
  'reddit.com',
  'facebook.com',
  'python.org',
  'imgur.com',
  'wikipedia.org',
  'youtube.com',
  'stackoverflow.com',
]

about 40% simply returned back their IP.

My solution:

• Resolve IP to DNS authority/server using Google DoH DNS

• Detect whether DNS returned authority

• Return response

• 30-50ms on average to resolve

• 90% takes 100ms to resolve

• No fail resolution penalties

PR for #17

Checklist:

• [x] Code follows the style guidelines
• [x] Code commented in relevant places
• [x] Changes to necessary documentation made
• [x] New and existing unit tests pass locally with changes

Tests Performed:

• [x] Upload data to Datastore
• [x] Retrieve data from Datastore
• [x] Map Visualization
• [x] Network Map Visualization
• [x] List other manual test cases performed

[arunk054]

You should be able to merge this to master then rebase your map_viz to master.

[thorncorona]

Rebased.