Behind Every Click: Understanding Client–Server Architecture

Murali — Thu, 04 Dec 2025 05:41:00 +0000

Client–server architecture is one of the most fundamental models used in modern application development.

It consists of two major components:

Client — the user or application making the request
Server — the machine that processes the request and returns the response

When a user wants to access a server, the simplest method is by pinging the server’s IP address. However, IP addresses are difficult to remember, which makes direct access impractical. To solve this problem, we use the Domain Name System (DNS).
DNS converts user-friendly domain names into IP addresses, allowing users to connect to the server seamlessly.

Server Performance and Scaling

A server with limited hardware for example, 2 CPUs and 4 GB RAM can process only a certain number of requests. When traffic increases significantly, users may experience delays or the server may even become unresponsive.

To handle this, we can scale the system in two ways:

1. Vertical Scaling (Scaling Up)

This involves increasing the physical resources of the server, such as upgrading to 16 CPUs and 128 GB RAM.
While this increases the server’s capacity, it introduces problems:

Resource wastage when traffic is low
Downtime during scaling, since the server needs to be restarted
Hardware limits — there is a maximum capacity beyond which upgrades are not possible

2. Horizontal Scaling (Scaling Out)

Instead of upgrading one large server, we duplicate multiple small servers with the same configuration (e.g., multiple 2-CPU, 4-GB-RAM servers).
Benefits include:

No downtime when adding or removing servers
Better cost efficiency
High fault tolerance
Efficient traffic management during peak times

However, when we clone servers, each server gets its own IP address, creating an important question…

How Do We Handle Multiple Server IPs If DNS Points to Only One
This is where Load Balancers come into play.
A load balancer sits between clients and servers. It exposes one public IP to the DNS and intelligently distributes incoming traffic to multiple backend servers.

Critical Design Considerations:

If multiple servers exist, how does the load balancer decide which server to send each request to?
How do we maintain user sessions across multiple servers? (e.g., login sessions)
How do auto-scaling groups work when traffic increases suddenly?
How do applications store shared files when servers are distributed?
How does health-checking ensure that traffic is never sent to a failed server?

Basic Data Types in Python

Murali — Sat, 18 Oct 2025 11:06:47 +0000

1. int (Integer)
Definition:
An integer is a whole number (positive, negative, or zero) without a decimal point.

Examples:

a = 10
b = -25
c = 0

Properties:

No limit on the size of an integer (Python handles big integers automatically).
Supports arithmetic operations: +, -, , /, //, %, *.

Example:

x = 5
y = 2
print(x + y)   # 7
print(x // y)  # 2  (integer division)
print(x ** y)  # 25 (power)

2. float (Floating Point)
Definition:
A float represents real numbers (numbers with decimals).

Examples:

pi = 3.14159
temperature = -5.4
height = 10.0

Properties:

Used for precise decimal calculations.
Supports all arithmetic operations.
You can use scientific notation: e = 1.23e4 # 1.23 × 10⁴ → 12300.0

Example:

a = 2.5
b = 4.0
print(a * b)    # 10.0

3. complex (Complex Number)
Definition:
A complex number has a real and an imaginary part, written as a + bj,
where a is real and b is imaginary.

Examples:

z1 = 2 + 3j
z2 = 1 - 4j

Properties:

z.real gives the real part.
z.imag gives the imaginary part.
Supports arithmetic operations.

Example:

z = 2 + 3j
print(z.real)  # 2.0
print(z.imag)  # 3.0
print(z * 2)   # (4+6j)

4. bool (Boolean)
Definition:
Boolean type has only two values: True and False.
Used in conditional logic and comparisons.

Examples:

is_active = True
is_admin = False

Properties:

bool is actually a subclass of int:
True → 1
False → 0

Example:

print(True + True)   # 2
print(False + True)  # 1
#Used in comparisons:
x = 10
y = 5
print(x > y)  # True
print(x == y) # False

5. str (String)
Definition:
A string is a sequence of characters enclosed in single, double, or triple quotes.

Examples:

name = "Ravi"
greeting = 'Hello'
paragraph = """This is
a multi-line string."""

Properties:

Strings are immutable (cannot be changed after creation).
You can concatenate (+), repeat (*), slice, and iterate.

Example:

s = "Python"
print(s[0])      # P
print(s[-1])     # n
print(s[0:3])    # Pyt
print(s + "3")   # Python3
print(s * 2)     # PythonPython
Common string methods:
text = "hello world"
print(text.upper())    # HELLO WORLD
print(text.capitalize()) # Hello world
print(text.replace("world", "Python"))  # hello Python
print(text.split())    # ['hello', 'world']

DEV Community: Murali

Behind Every Click: Understanding Client–Server Architecture

Server Performance and Scaling

1. Vertical Scaling (Scaling Up)

2. Horizontal Scaling (Scaling Out)

Basic Data Types in Python