How to Monitor Redis with Zabbix Agent2: A Complete Guide

Thanks to community expert Wanger for the contribution.

1. Monitoring Redis Implementation Principles

The Redis plugin is located in

zabbix-agent2/src/go/plugins/redis

. The main file

redis.go

implements the Exporter interface and dispatches functions based on key values to obtain specific data.

The

whereToConnect

function builds a URI from the configuration file and key parameters; the first key parameter can be a Redis session name or a URI. The plugin supports multiple sessions, allowing monitoring of several Redis instances, and a URI defined in the key takes precedence over the configuration file.

Configuration parameter priority (from highest to lowest):

Key parameters in the monitoring item

Parameters in

Plugins.Redis.Sessions.<sessionName>.<parameter>

Parameters in

Plugins.Redis.<parameter>

(configuration file)

Plugin default values

The plugin can retrieve Redis INFO command output, server configuration, health status, and the number of slow‑query logs.

01 – Getting INFO

This corresponds to executing the

INFO

command in Redis. By default it returns all sections; an optional

section

argument can limit the output. The result is parsed by

parseRedisInfo

into a map.

02 – Getting CONFIG

This is equivalent to running

CONFIG GET *

on the client, which returns all configuration parameters by default; a

pattern

argument can request specific settings.

03 – Getting Health Status

The health check simply executes the

PING

command.

04 – Getting Slow‑Query Log Count

The plugin obtains the number of slow‑query logs by querying the last slow‑query ID.

Connection Management

Returning to

redis.go

, the

GetConnection

method obtains a connection, updates

lastTimeAccess

, and compares it with the

keepalive

setting to close idle connections. If no connection exists, a new one is created; a mutex ensures thread safety. Multiple URIs can be added to monitor different instances.

Configuration File Parsing

The

config.go

file reads the plugin configuration. It shows that session parameters (

Plugins.Redis.Sessions.<sessionName>.<parameter>

) have higher priority than general plugin parameters (

Plugins.Redis.<parameter>

).

2. Monitoring Redis with Zabbix

After understanding the implementation, use the Redis template in Zabbix. Modify the URI macro; the default address is

tcp://127.0.0.1:6379

and both TCP and Unix socket connections are supported. If Redis runs in protected mode, edit

redis.conf

to set

protected-mode no

and restart the server.

<code>DENIED Redis Is Running In Protected Mode Because Protected Mode Is Enabled, No Bind Address Was Specified,
No Authentication Password Is Requested To Clients. In This Mode Connections Are Only Accepted From The Loopback Interface.
If You Want To Connect From External Computers To Redis You May Adopt One Of The Following Solutions:
1) Just Disable Protected Mode Sending The Command 'CONFIG SET Protected-Mode No' From The Loopback Interface By Connecting To Redis From The Same Host The Server Is Running, However MAKE SURE Redis Is Not Publicly Accessible From Internet If You Do So. Use CONFIG REWRITE To Make This Change Permanent.
2) Alternatively You Can Just Disable The Protected Mode By Editing The Redis Configuration File, And Setting The Protected Mode Option To 'No', And Then Restarting The Server.
3) If You Started The Server Manually Just For Testing, Restart It With the '--Protected-Mode No' Option.
4) Setup A Bind Address Or An Authentication Password. NOTE: You Only Need To Do One Of The Above Things In Order For The Server To Start Accepting Connections From The Outside.</code>

After fixing the configuration, the Redis metrics appear in Zabbix.