How to Auto‑Discover and Monitor Redis Ports with Zabbix

Zabbix Auto-Discovery of Redis Ports and Monitoring

When a server runs many Redis instances, manually adding each to Zabbix is time‑consuming; Zabbix's auto‑discovery can automatically find Redis ports and collect metrics.

Monitoring Items

Redis metrics are obtained via the

info

command. Example items include:

<code>uptime_in_days                ## days Redis has been up
connected_clients            ## number of client connections
blocked_clients              ## clients waiting for blocking commands
used_memory_peak_human        ## peak memory usage
used_memory                  ## current memory usage
expired_keys                  ## number of expired keys
evicted_keys                  ## number of evicted keys
keyspace_misses               ## cache misses
keyspace_hits                 ## cache hits
connected_slaves              ## number of slave servers
rejected_connections          ## connections rejected due to limit</code>

Additional items can be retrieved with the

info

command as needed.

Develop Auto‑Discovery Scripts

Both shell and Python scripts can be used; two examples are provided.

Shell Script

<code>#!/bin/bash
# Auto‑discover Redis ports
port=(`sudo netstat -tpln | awk -F "[ :]+" '/redis/ && /0.0.0.0/ {print $5}'`)
printf '{
"data":[
'
for key in ${!port[@]}
do
    if [[ "${#port[@]}" -gt 1 && "${key}" -ne "$((${#port[@]}-1))" ]]; then
        socket=`ps aux|grep ${port[${key}]}|grep -v grep|awk -F '=' '{print $10}'|cut -d ' ' -f 1`
        printf '	 {
'		"{#REDISPORT}":"${port[${key}]}"},
    else
        socket=`ps aux|grep ${port[${key}]}|grep -v grep|awk -F '=' '{print $10}'|cut -d ' ' -f 1`
        printf '	 {
'		"{#REDISPORT}":"${port[${key}]}"}
    fi
done
printf '	 ]
}
'</code>

Python Script

<code>#!/usr/bin/env python
import os, json
t=os.popen("""sudo netstat -tlpn |grep redis-server|grep 0.0.0.0|awk '{print $4}'|awk -F: '{print $2}' """)
ports = []
for port in t.readlines():
    r = os.path.basename(port.strip())
    ports += [{'{#REDISPORT}': r}]
print(json.dumps({'data': ports}, sort_keys=True, indent=4, separators=(',', ':')))
</code>

These scripts discover Redis ports; they can be adapted to discover other services by passing the service name as a parameter.

Configure the Agent on the Monitored Host

(1) Copy one of the scripts to the host, e.g.,

/etc/zabbix/scripts/discovery_redis.py

, and make it executable.

<code># mkdir /etc/zabbix/scripts
# chmod +x discovery_redis.py</code>

(2) Create a Zabbix user‑parameter file

userparameter_discovery_redis.conf

:

<code>UserParameter=redis.discovery,/etc/zabbix/scripts/discovery_redis.py
UserParameter=redis.stats[*],/usr/local/redis-3.2.9/src/redis-cli -h 127.0.0.1 -p $1 info | grep -w $2 | cut -d ':' -f2</code>

(3) Edit

zabbix_agentd.conf

to include the custom directory and allow unsafe parameters:

<code>Include=/etc/zabbix/zabbix_agentd.conf.d/*.conf
UnsafeUserParameters=1</code>

(4) Grant the Zabbix user sudo rights for

netstat

(or set the set‑uid bit):

<code># visudo
Defaults:zabbix !requiretty
zabbix ALL=(root) NOPASSWD:/bin/netstat</code>

(5) Restart the agent and test with

zabbix_get

:

<code># service zabbix-agent restart
zabbix_get -s 10.2.42.16 -p 10050 -k redis.discovery
zabbix_get -s 10.2.42.16 -p 10050 -k redis.stats[6383,expired_keys]
</code>

If zabbix_get is missing, install it via yum install zabbix_get -y .

Server‑Side Configuration (Web UI)

Create a template, an application set, and a discovery rule. Configure optional filters and regular expressions to limit discovered hosts.

Create Item Prototypes

Within the discovery rule, add item prototypes such as:

<code>redis_stats[{#REDISPORT},evicted_keys]</code>

Explanation:

redis_stats – the key defined on the agent side.

{#REDISPORT} – the macro supplied by the discovery script.

evicted_keys – the specific Redis metric to collect.

Create Graph Prototypes

Define graph prototypes under the same discovery rule to visualize metrics.

Create Triggers

Add trigger prototypes to the discovery rule, for example monitoring evicted keys.

Add the Template to the Host

Assign the created template to the target host, ensuring the discovery script and agent configuration are present on that host.

After linking the template, you can view the latest data and graphs for each discovered Redis instance.