AWS › Amazon ElastiCache (Redis & Memcached)

What monitoring metrics are most important to track for an ElastiCache deployment in production?

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Answer

Key metrics to monitor include CPU utilization and memory usage to detect resource pressure before it causes evictions or slowdowns, cache hit and miss ratio to understand how effectively the cache is reducing load on your database, current connections to detect potential connection exhaustion, and replication lag on Redis replicas to ensure read replicas are not falling too far behind the primary node.

aws cloudwatch get-metric-statistics --namespace AWS/ElastiCache --metric-name CacheHitRate --dimensions Name=CacheClusterId,Value=my-cache --start-time 2026-09-01T00:00:00Z --end-time 2026-09-07T00:00:00Z --period 3600 --statistics Average

Real-world example An operations team sets up a CloudWatch alarm that triggers when the cache hit ratio for their Redis cluster drops below a healthy threshold, prompting investigation into whether the cache size needs to be increased.

Common follow-ups: What causes a low cache hit ratio and how can it be improved?;How do you set up automated alerts for ElastiCache memory pressure?

Monitoring (CloudWatch);AWS Cost Management & Billing