Redis Commands

Redis is the in-memory cache and queue server used by Zal Ultra for caching, sessions, and background job processing.

🟠 MEDIUM RISK

Restarting Redis will clear all cached data and may cause temporary slowdowns. Queue jobs will resume after restart.

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Table of Contents

1. Service Management
2. Redis CLI
3. Cache Management
4. Queue Monitoring
5. Memory Management
6. Troubleshooting

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Service Management

Check Redis Status

sudo systemctl status redis-server

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Start Redis

sudo systemctl start redis-server

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Stop Redis

🟠 CACHE LOSS

Stopping Redis will clear all cached data and interrupt queue processing.

sudo systemctl stop redis-server

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Restart Redis

🟠 CACHE CLEARED

Restart clears all cached data. Application will rebuild cache on demand.

sudo systemctl restart redis-server

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Enable on Boot

sudo systemctl enable redis-server

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Redis CLI

Connect to Redis

redis-cli

Ping Redis (Test Connection)

redis-cli ping
# Expected: PONG

Check Redis Info

redis-cli info

Check Specific Section

redis-cli info memory
redis-cli info clients
redis-cli info stats

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Cache Management

View All Keys (Use with Caution)

🟠 PERFORMANCE IMPACT

On large databases, KEYS * can block Redis. Use SCAN instead in production.

redis-cli KEYS "*"

Count All Keys

redis-cli DBSIZE

Search Keys by Pattern

redis-cli KEYS "laravel_cache:*"
redis-cli KEYS "laravel_database_*"

Get Key Value

redis-cli GET "key_name"

Delete Specific Key

redis-cli DEL "key_name"

Delete Keys by Pattern

🟠 DATA DELETION

This permanently deletes matching keys.

redis-cli KEYS "laravel_cache:*" | xargs redis-cli DEL

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Clear All Cache (FLUSHDB)

🔴 CLEARS ALL DATA

This removes ALL data from the current database.

redis-cli FLUSHDB

Clear All Databases (FLUSHALL)

🔴 CLEARS EVERYTHING

This removes ALL data from ALL Redis databases.

redis-cli FLUSHALL

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Clear Laravel Cache via Artisan

# Preferred method - clears only Laravel cache
cd /var/www/html
php artisan cache:clear

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Queue Monitoring

Check Queue Length

redis-cli LLEN "queues:default"
redis-cli LLEN "queues:sms"
redis-cli LLEN "queues:high"

View Queue Contents

redis-cli LRANGE "queues:default" 0 10

Check Failed Jobs Queue

redis-cli LLEN "queues:failed"

Monitor Redis in Real-time

redis-cli MONITOR

Press Ctrl+C to stop.

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Memory Management

Check Memory Usage

redis-cli INFO memory

Key Memory Stats

redis-cli INFO memory | grep -E "used_memory_human|maxmemory_human|mem_fragmentation"

Check Memory for Specific Key

redis-cli MEMORY USAGE "key_name"

Find Largest Keys

redis-cli --bigkeys

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Set Memory Limit

# In redis.conf or via CLI
redis-cli CONFIG SET maxmemory 512mb
redis-cli CONFIG SET maxmemory-policy allkeys-lru

Check Current Memory Policy

redis-cli CONFIG GET maxmemory
redis-cli CONFIG GET maxmemory-policy

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Troubleshooting

Common Issues

Redis Won't Start

# Check error log
sudo tail -100 /var/log/redis/redis-server.log

# Check permissions
sudo chown -R redis:redis /var/lib/redis

Connection Refused

# Check if Redis is running
sudo systemctl status redis-server

# Check if listening
sudo netstat -tlnp | grep 6379

# Check bind address in config
sudo grep "bind" /etc/redis/redis.conf

Memory Full

# Check memory usage
redis-cli INFO memory

# Clear old cache
redis-cli FLUSHDB

# Or set memory limit with eviction
redis-cli CONFIG SET maxmemory 1gb
redis-cli CONFIG SET maxmemory-policy allkeys-lru

Slow Performance

# Check slow log
redis-cli SLOWLOG GET 10

# Check connected clients
redis-cli CLIENT LIST | wc -l

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Configuration File

sudo nano /etc/redis/redis.conf

Important Settings

# Memory limit
maxmemory 1gb

# Eviction policy
maxmemory-policy allkeys-lru

# Persistence (disable for pure cache)
save ""
appendonly no

# Bind address (localhost only for security)
bind 127.0.0.1

After config changes:

sudo systemctl restart redis-server

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Check Redis Version

redis-server --version
redis-cli --version

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Quick Reference Card

Action	Command
Check status	sudo systemctl status redis-server
Start	sudo systemctl start redis-server
Stop	sudo systemctl stop redis-server
Restart	sudo systemctl restart redis-server
Connect CLI	redis-cli
Ping test	redis-cli ping
Memory info	redis-cli INFO memory
Key count	redis-cli DBSIZE
Clear cache	redis-cli FLUSHDB
Queue length	redis-cli LLEN "queues:default"
Monitor	redis-cli MONITOR
Config file	/etc/redis/redis.conf
Log file	/var/log/redis/redis-server.log