Introduction

Redis distributed lock not acquired when key already held or lock timeout issue. This guide provides step-by-step diagnosis and resolution.

Symptoms

Typical error output:

bash
Error: Redis operation failed
Check Redis logs and use INFO command
redis-cli INFO

Common Causes

  1. 1.Resource configuration insufficient
  2. 2.Network connectivity issue
  3. 3.Configuration parameter incorrect
  4. 4.Version compatibility issue

Step-by-Step Fix

Step 1: Check Current State

bash
redis-cli INFO
redis-cli CONFIG GET "*"
redis-cli SLOWLOG GET 10

Step 2: Identify Root Cause

bash
redis-cli INFO
redis-cli CONFIG GET "*"
redis-cli SLOWLOG GET 10

Step 3: Apply Primary Fix

```bash # Primary fix redis-cli CONFIG SET parameter value

# Verify redis-cli CONFIG GET parameter ```

Step 4: Apply Alternative Fix

```bash # Alternative fix: Check configuration redis-cli CONFIG GET "*memory*" redis-cli CONFIG GET "*timeout*"

# Update settings redis-cli CONFIG SET parameter value

# Verify the fix redis-cli INFO ```

Step 5: Verify the Fix

bash
redis-cli INFO
redis-cli PING
# Should return PONG and healthy stats

Common Pitfalls

  • Not using connection pooling for high-throughput applications
  • Setting maxmemory without eviction policy
  • Using KEYS command in production
  • Not monitoring replication lag

Best Practices

  • Monitor Redis memory and fragmentation regularly
  • Use SCAN instead of KEYS for key enumeration
  • Configure appropriate eviction policy for workload
  • Implement proper backup strategy (RDB or AOF)
  • Redis Connection Refused
  • Redis High Latency
  • Redis Cluster Down
  • Redis Persistence Failed