The Uptime Engineer
👋 Hi, I am Yoshik Karnawat
Don’t scroll past, this week’s 180 second read might just save you hours at work.
Facts about DNS
The internet processes 115 billion DNS queries every single day
Before DNS existed in 1983, the internet used one file called HOSTS.TXT
Only 13 root server clusters handle DNS queries for the entire planet
One DNS provider alone handled 41.97 trillion queries in 2023
You type google.com into your browser and boom. It loads instantly.
But here’s the real question:
How does your computer actually find Google’s servers in the first place?
The answer: DNS - Domain Name System.
And if you’re learning DevOps, understanding DNS isn’t optional, it’s foundational.
Why DNS exists in the first place
Computers don’t understand names like google.com.
They talk in IP addresses like 142.250.xx.xx.
Without DNS, you’d need to memorize IPs for every site you visit. Imagine remembering 142.250.xx.xx instead of typing “google.com”. Absurd, right?
So DNS was invented to fix that.
It’s the internet’s phonebook, translating human-readable domains into machine-friendly IPs.website
What Happens When You Visit a Website
Step 1: Local cache check
Your browser checks if it already knows the IP. If you’ve been there recently, it might be stored locally.
Step 2: Ask the DNS resolver
If not cached, your computer asks a DNS resolver. Usually your ISP’s or a public one like Google’s 8.8.8.8 or Cloudflare’s 1.1.1.1.
Step 3: Query the root DNS server
The resolver queries a root DNS server.
There are only 13 sets of these globally. They don’t know your domain, but they point to the right top-level domain (TLD) like .com or .org.
Step 4: TLD server lookup
The .com server sends your resolver to the authoritative server for example.com.
This server returns the actual IP (e.g., 93.184.216.34).
Step 6: Your browser connects
Your computer now knows exactly where to go and connects to that IP.
All this happens in milliseconds.
That’s how the web feels instant, even though your computer just traveled a miniature roadmap of the internet.
The hierarchy that makes DNS work
Think of DNS like a library system:
Root nameservers = The catalog itself (points you to the right section)
TLD servers = A specific section page (like all books in "Science")
Authoritative nameservers = The exact shelf row with your book
No single server stores every record.
Each one knows just enough to point to the next, creating a scalable, resilient lookup chain.
Common DNS record types you'll encounter
When you start working with DNS, you'll see different types of records:
A Record: Maps a domain name to an IPv4 address (example.com → 93.184.216.34)
AAAA Record: Maps to an IPv6 address
CNAME Record: Creates an alias (www.example.com → example.com)
MX Record: Directs email to mail servers
TXT Record: Stores text information (often used for verification)
You don’t need to memorize these yet, just know what they do.
Once you start configuring infrastructure, you’ll see how often DNS is the silent culprit behind outages.
⚡Your turn: Open your terminal and run nslookup google.com to see DNS in action. You’ll see exactly which IP address your DNS resolver returns for Google.