Monitoring

Production monitoring setup for NestJS RedisX.

Key Metrics by Component

Cache Metrics

Metric	Description	Good	Warning	Critical
cache_hit_rate	Hits / Total	>90%	80-90%	<80%
cache_latency_p99	99th percentile	<5ms	5-20ms	>20ms
cache_eviction_rate	Evictions/sec	Low	Increasing	Spiking

Lock Metrics

Metric	Description	Good	Warning	Critical
lock_acquisition_time_p99	Wait time	<100ms	100-500ms	>500ms
lock_timeout_rate	Timeouts / Total	<1%	1-5%	>5%
lock_held_duration_p99	Hold time	<TTL/2	~TTL	>TTL

Rate Limit Metrics

Metric	Description	Good	Warning	Critical
ratelimit_rejection_rate	Rejected / Total	<5%	5-20%	>20%
ratelimit_near_limit	>80% of limit	<10%	10-30%	>30%

Stream Metrics

Metric	Description	Good	Warning	Critical
stream_consumer_lag	Pending messages	<100	100-1000	>1000
stream_dlq_size	DLQ message count	0	1-10	>10
stream_processing_time_p99	Handler time	<1s	1-5s	>5s

PromQL Queries

Cache Dashboard

# Hit Rate
sum(rate(redisx_cache_hits_total[5m])) / 
(sum(rate(redisx_cache_hits_total[5m])) + sum(rate(redisx_cache_misses_total[5m])))

# Latency P99
histogram_quantile(0.99, sum(rate(redisx_cache_duration_seconds_bucket[5m])) by (le, operation))

# Operations per Second
sum(rate(redisx_cache_operations_total[5m])) by (operation)

Lock Dashboard

# Timeout Rate
sum(rate(redisx_lock_timeouts_total[5m])) / sum(rate(redisx_lock_attempts_total[5m]))

# Active Locks
redisx_locks_active

# Wait Time P99
histogram_quantile(0.99, sum(rate(redisx_lock_wait_seconds_bucket[5m])) by (le))

Stream Dashboard

# Consumer Lag
redisx_stream_consumer_lag{stream="jobs"}

# Processing Rate
sum(rate(redisx_stream_messages_processed_total[5m])) by (stream)

# DLQ Size
redisx_stream_length{stream=~".*:dlq"}

Grafana Dashboard JSON

{
  "title": "NestJS RedisX Overview",
  "panels": [
    {
      "title": "Cache Hit Rate",
      "type": "stat",
      "fieldConfig": {
        "defaults": {
          "thresholds": {
            "steps": [
              { "value": 0, "color": "red" },
              { "value": 0.8, "color": "yellow" },
              { "value": 0.9, "color": "green" }
            ]
          },
          "unit": "percentunit"
        }
      },
      "targets": [{
        "expr": "sum(rate(redisx_cache_hits_total[5m])) / (sum(rate(redisx_cache_hits_total[5m])) + sum(rate(redisx_cache_misses_total[5m])))"
      }]
    },
    {
      "title": "Lock Timeout Rate",
      "type": "stat",
      "targets": [{
        "expr": "sum(rate(redisx_lock_timeouts_total[5m])) / sum(rate(redisx_lock_attempts_total[5m]))"
      }]
    },
    {
      "title": "Stream Consumer Lag",
      "type": "graph",
      "targets": [{
        "expr": "redisx_stream_consumer_lag",
        "legendFormat": "{{stream}} - {{group}}"
      }]
    }
  ]
}

SLOs

Recommended SLOs

Component	SLI	SLO
Cache	Hit rate	>90% over 7 days
Cache	Latency p99	<10ms over 7 days
Locks	Timeout rate	<1% over 7 days
Streams	Lag	<1000 99% of time
Streams	DLQ size	0 99% of time

Error Budget

# Cache hit rate error budget burn
1 - (sum(rate(redisx_cache_hits_total[7d])) / 
     (sum(rate(redisx_cache_hits_total[7d])) + sum(rate(redisx_cache_misses_total[7d]))))
/ (1 - 0.90)  # SLO target

Health Endpoints

// health.controller.ts
@Controller('health')
export class HealthController {
  @Get('live')
  liveness() {
    return { status: 'ok' };
  }

  @Get('ready')
  async readiness() {
    const redis = await this.redis.ping();
    
    return {
      status: redis ? 'ok' : 'degraded',
      checks: {
        redis: redis ? 'ok' : 'failed',
      },
    };
  }
}

Next Steps

• Alerting — Configure alerts
• Runbooks — Incident response