Upstream blocks in Nginx - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an upstream block in nginx?

An upstream block defines a group of backend servers that nginx can proxy requests to. It helps distribute traffic among multiple servers.

beginner

How do you define multiple servers inside an upstream block?

Inside the upstream block, list each server with the server directive, for example:<br>

upstream backend {
  server 192.168.1.10;
  server 192.168.1.11;
}

beginner

What is the purpose of the proxy_pass directive in relation to upstream blocks?

The proxy_pass directive tells nginx to forward client requests to the servers defined in an upstream block, enabling load balancing.

intermediate

Name two load balancing methods supported in nginx upstream blocks.

Two common methods are:<br>1. round-robin (default): requests are distributed evenly.<br>2. least_conn: requests go to the server with the fewest active connections.

intermediate

How can you mark a server as a backup in an upstream block?

Add the backup parameter to the server directive. This server will only receive traffic if all primary servers are down.<br>

server 192.168.1.12 backup;

What does an upstream block in nginx do?

A Configures SSL certificates

B Sets client request timeout

C Defines backend servers for load balancing

D Specifies static file locations

An upstream block groups backend servers to distribute client requests.

Which directive inside an upstream block lists backend servers?

A proxy_pass

B server

C location

D listen

The server directive defines each backend server inside the upstream block.

What is the default load balancing method in nginx upstream blocks?

A round-robin

B ip_hash

C random

D least_conn

The default method is round-robin, which distributes requests evenly.

How do you tell nginx to use an upstream block in a server configuration?

A Using <code>proxy_pass</code> with the upstream name

B Using <code>listen</code> directive

C Using <code>root</code> directive

D Using <code>error_page</code>

The proxy_pass directive forwards requests to the named upstream group.

What does the backup parameter do in an upstream server directive?

A Marks the server as primary

B Enables SSL on the server

C Disables the server

D Marks the server as a fallback used only if others fail

The backup server is used only when all primary servers are unavailable.

Explain how nginx uses an upstream block to balance load between servers.

Think about how nginx forwards requests to several servers.

Describe how to configure a backup server in an nginx upstream block and why it is useful.

Consider what happens if main servers go down.