Monitor Redis with INFO, SLOWLOG, and Latency

Intermediate10 min

Track Redis health, performance bottlenecks, and slow commands using built-in diagnostic tools for production observability.

Prerequisites

-Redis installed and running
-redis-cli available

Steps

Get a full server overview

Retrieve comprehensive server stats including memory, clients, and keyspace.

$ redis-cli INFO

Use 'redis-cli INFO memory' or 'redis-cli INFO stats' to filter to a specific section.

Check memory usage breakdown

Inspect detailed memory allocation and fragmentation ratio.

$ redis-cli INFO memory

Review slow commands

List the most recent commands that exceeded the slow log threshold.

$ redis-cli SLOWLOG GET 10

Default threshold is 10ms. Lower it with 'CONFIG SET slowlog-log-slower-than 5000' (microseconds).

Enable latency monitoring

Activate the latency monitor to track spikes over time.

$ redis-cli CONFIG SET latency-monitor-threshold 5

View latency history

Display recorded latency events and their timestamps.

$ redis-cli LATENCY LATEST

Monitor commands in real time

Stream all commands being processed by Redis for live debugging.

$ redis-cli MONITOR

MONITOR adds overhead and outputs every command. Use briefly for debugging and never in production for extended periods.

Full Script

full-script.sh

#!/bin/bash
# Redis Monitoring Dashboard
set -euo pipefail

echo "=== Server Overview ==="
redis-cli INFO server | grep -E "redis_version|uptime_in_days|connected_clients"

echo ""
echo "=== Memory ==="
redis-cli INFO memory | grep -E "used_memory_human|used_memory_peak_human|mem_fragmentation_ratio"

echo ""
echo "=== Stats ==="
redis-cli INFO stats | grep -E "total_commands_processed|keyspace_hits|keyspace_misses|expired_keys|evicted_keys"

HITS=$(redis-cli INFO stats | grep keyspace_hits | cut -d: -f2 | tr -d '\r')
MISSES=$(redis-cli INFO stats | grep keyspace_misses | cut -d: -f2 | tr -d '\r')
if [ "$((HITS + MISSES))" -gt 0 ]; then
  echo "Cache hit rate: $(echo "scale=2; $HITS * 100 / ($HITS + $MISSES)" | bc)%"
fi

echo ""
echo "=== Slow Log (last 5) ==="
redis-cli SLOWLOG GET 5

echo ""
echo "=== Latency ==="
redis-cli LATENCY LATEST

echo ""
echo "=== Connected Clients ==="
redis-cli CLIENT LIST | wc -l
echo "total connections"

echo ""
echo "=== Keyspace ==="
redis-cli INFO keyspace

FAQ

Discussion

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#!/bin/bash # Redis Monitoring Dashboard set -euo pipefail echo "=== Server Overview ===" redis-cli INFO server | grep -E "redis_version|uptime_in_days|connected_clients" echo "" echo "=== Memory ===" redis-cli INFO memory | grep -E "used_memory_human|used_memory_peak_human|mem_fragmentation_ratio" echo "" echo "=== Stats ===" redis-cli INFO stats | grep -E "total_commands_processed|keyspace_hits|keyspace_misses|expired_keys|evicted_keys" HITS=$(redis-cli INFO stats | grep keyspace_hits | cut -d: -f2 | tr -d '\r') MISSES=$(redis-cli INFO stats | grep keyspace_misses | cut -d: -f2 | tr -d '\r') if [ "$((HITS + MISSES))" -gt 0 ]; then echo "Cache hit rate: $(echo "scale=2; $HITS * 100 / ($HITS + $MISSES)" | bc)%" fi echo "" echo "=== Slow Log (last 5) ===" redis-cli SLOWLOG GET 5 echo "" echo "=== Latency ===" redis-cli LATENCY LATEST echo "" echo "=== Connected Clients ===" redis-cli CLIENT LIST | wc -l echo "total connections" echo "" echo "=== Keyspace ===" redis-cli INFO keyspace