Weighted round-robin in Nginx - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is weighted round-robin in nginx?

Weighted round-robin is a load balancing method in nginx that distributes client requests to servers based on assigned weights, sending more requests to servers with higher weights.

beginner

How do you assign weights to servers in nginx configuration for weighted round-robin?

You assign weights by adding the 'weight' parameter to each server in the upstream block, like: server 192.168.1.1 weight=3; which means this server gets 3 times more requests than a server with weight=1.

beginner

Example of an nginx upstream block using weighted round-robin?

upstream backend { server 192.168.1.1 weight=3; server 192.168.1.2 weight=1; } This sends 3 requests to 192.168.1.1 for every 1 request to 192.168.1.2.

intermediate

Why use weighted round-robin instead of simple round-robin?

Weighted round-robin lets you send more traffic to stronger or faster servers by assigning higher weights, improving performance and resource use compared to simple round-robin which treats all servers equally.

beginner

What happens if all servers have the same weight in nginx weighted round-robin?

If all servers have the same weight, weighted round-robin behaves like simple round-robin, distributing requests evenly across all servers.

In nginx weighted round-robin, what does a higher weight mean for a server?

A It receives more client requests

B It receives fewer client requests

C It is ignored by nginx

D It becomes a backup server

A higher weight means the server receives more client requests compared to servers with lower weights.

How do you specify a server with weight 5 in nginx upstream configuration?

A server 192.168.1.1 count=5;

B server 192.168.1.1 priority=5;

C server 192.168.1.1 load=5;

D server 192.168.1.1 weight=5;

The correct syntax to assign weight is 'weight=5' in the server directive.

What load balancing method does nginx use if weights are not specified?

A IP hash

B Least connections

C Simple round-robin

D Random

Without weights, nginx defaults to simple round-robin, distributing requests evenly.

If server A has weight 4 and server B has weight 1, how many requests does server A get for every request to server B?

A 4

B 1

C 5

D 0.25

Server A gets 4 times more requests than server B because its weight is 4.

Which nginx directive block contains the weighted round-robin server definitions?

A location

B upstream

C server

D http

The 'upstream' block defines backend servers and their weights for load balancing.

Explain how weighted round-robin works in nginx and why it might be useful.

Think about sending more work to stronger servers.

Write a simple nginx upstream configuration using weighted round-robin with two servers, one with weight 2 and the other with weight 1.

Use 'server IP weight=number;' inside upstream.