Inactive Memorystore Instance

Explanation

Memorystore instances that are provisioned but unused - whether due to deprecated services, orphaned environments, or development/testing phases ending - continue to incur memory and infrastructure charges. Because usage-based metrics like client connections or cache hit ratios are not tied to billing, an idle instance costs the same as a heavily used one. This makes it critical to identify and decommission inactive caches.

Relevant Billing Model

Billed based on: * Provisioned memory capacity per hour * Network egress (if applicable) * Optional HA configurations incur additional cost Charges accrue even if the instance is not actively serving traffic or receiving connections.

Detection

• Identify instances with zero or near-zero connected clients over time
• Evaluate cache hit ratio and operation throughput (gets/sets) for inactivity
• Check if the instance is tied to an application still in use
• Review environments (e.g., test, staging) for abandoned or duplicated caches
• Assess whether data stored in the cache is static or outdated

Remediation

• Decommission inactive or obsolete Memorystore instances
• Consolidate fragmented caching layers across services or environments
• Use automated tagging and monitoring to flag long-idle instances
• For intermittent workloads, consider re-creating the cache on demand via IaC or CI/CD pipelines