Host-Level Metrics - Amazon ElastiCache for Redis

Host-Level Metrics

The AWS/ElastiCache namespace includes the following host-level metrics for individual cache nodes.

See Also

Metric Description Unit
CPUUtilization The percentage of CPU utilization for the entire host. Because Redis is single-threaded, we recommend you monitor EngineCPUUtilization metric for nodes with 4 or more vCPUs. Percent
CPUCreditBalance

The number of earned CPU credits that an instance has accrued since it was launched or started. For T2 Standard, the CPUCreditBalance also includes the number of launch credits that have been accrued.

Credits are accrued in the credit balance after they are earned, and removed from the credit balance when they are spent. The credit balance has a maximum limit, determined by the instance size. After the limit is reached, any new credits that are earned are discarded. For T2 Standard, launch credits do not count towards the limit.

The credits in the CPUCreditBalance are available for the instance to spend to burst beyond its baseline CPU utilization.

When an instance is running, credits in the CPUCreditBalance do not expire. When a T3 or T3a instance stops, the CPUCreditBalance value persists for seven days. Thereafter, all accrued credits are lost. When a T2 instance stops, the CPUCreditBalance value does not persist, and all accrued credits are lost.

CPU credit metrics are available at a five-minute frequency only.

Credits (vCPU-minutes)
CPUCreditUsage

The number of CPU credits spent by the instance for CPU utilization. One CPU credit equals one vCPU running at 100% utilization for one minute or an equivalent combination of vCPUs, utilization, and time (for example, one vCPU running at 50% utilization for two minutes or two vCPUs running at 25% utilization for two minutes).

CPU credit metrics are available at a five-minute frequency only. If you specify a period greater than five minutes, use the Sum statistic instead of the Average statistic.

Credits (vCPU-minutes)
FreeableMemory The amount of free memory available on the host. This is derived from the RAM, buffers, and cache that the OS reports as freeable. Bytes
NetworkBytesIn The number of bytes the host has read from the network. Bytes
NetworkBytesOut The number of bytes sent out on all network interfaces by the instance. Bytes
NetworkPacketsIn The number of packets received on all network interfaces by the instance. This metric identifies the volume of incoming traffic in terms of the number of packets on a single instance. Count
NetworkPacketsOut The number of packets sent out on all network interfaces by the instance. This metric identifies the volume of outgoing traffic in terms of the number of packets on a single instance. Count
SwapUsage The amount of swap used on the host. Bytes