LOAD BALANCERS
One forwards blind.
One reads the path.
BOTH ARE CALLED A LOAD BALANCER
A load balancer sits in front of your servers
and picks one per request.
LAYER 4
TRANSPORT
BALANCER
picks by IP and port
It picks a server before it knows what you asked for.
LAYER 7
APPLICATION
BALANCER
reads path + headers
It reads the path first — so /api and /video go different places.
L4 — never opens the packet.
Picks by IP and port alone.
L7 — opens every request.
Picks by path and headers.
One forwards blind.
One reads the path.
Save this before your
next design review.
