Amazon ElastiCache adds thirteen new Amazon CloudWatch metrics for network capacity planning and engine diagnostics

Amazon ElastiCache customers can now detect network throttling, memory fragmentation, and connection exhaustion, using thirteen new Amazon CloudWatch metrics for node-based clusters. You can monitor these host-level and engine-level diagnostics directly from CloudWatch without running INFO commands on individual nodes or calculating baselines from raw byte counters.

• Network capacity: NetworkBaselineUsageInPercentage, NetworkBaselineUsageOutPercentage, NetworkBaselineMaxUsageInPercentage, and NetworkBaselineMaxUsageOutPercentage report network utilization relative to instance baseline, enabling portable alarms that remain valid across instance type changes. Values above 100 percent signal that a host is consuming burst credits, a leading indicator that a sustained workload will eventually lead to credit exhaustion and throttling. The variants capturing max report per-second bursts that averaged metrics can hide.
• Memory health: UsedMemoryDataset shows memory consumed by actual stored data excluding engine overhead. AllocatorFragmentationBytes and AllocatorFragmentationRatio isolate fragmentation that the activedefrag parameter can address. MajorPageFaults captures OS-level page faults that indicate memory pressure beyond what the engine can surface.
• Connectivity health: BlockedConnections and RejectedConnections surface connections waiting on blocking commands and connections turned away when the maxclients limit is reached. When RejectedConnections is non-zero, raise maxclients or diagnose client-side connection pool leaks.
• Pub/sub workloads: PubSubChannels and PubSubShardChannels expose active classic and sharded channels on each node. When classic channel counts are growing with utilization, consider switching to sharded pub/sub to scale horizontally.
• Command throughput: ProcessedCommands provides total command throughput across all command types.

These metrics are available for node-based clusters in all commercial AWS Regions and the AWS China and AWS GovCloud (US) Regions where ElastiCache is supported, at no additional cost.

To get started, view the new metrics in the ElastiCache console monitoring tab or in the AWS/ElastiCache namespace in the CloudWatch console. To learn more, see Host-Level Metrics and Metrics for Valkey and Redis OSS.