Monitoring Lambda Managed Instances

LMI publishes CloudWatch metrics so you can watch fleet utilisation, remaining capacity, and per-function execution environment behaviour. Metrics help right-size memory, interpret scaling, and spot concurrency pressure.

For full metric lists, dimensions, and console navigation, use Monitoring Lambda Managed Instances as the product reference.

Two metric scopes

Scope	What it answers	Example dimensions (per AWS)
Capacity provider	How hard the managed fleet is working and how much headroom remains	CapacityProviderName, InstanceType
Execution environment	How a specific function version uses CPU, memory, and concurrency on that fleet	CapacityProviderName, FunctionName, Resource

For LMI, the Resource dimension on execution-environment metrics targets function versions — format <FunctionName>:<FunctionVersion> (not aliases-only semantics in the same way).

Highlights (what to watch)

Capacity provider (fleet) level

Metric (names per AWS)	Use
CPUUtilization, MemoryUtilization	Overall pressure across instances behind the provider
vCPUAvailable, MemoryAvailable	Headroom still allocatable to environments
vCPUAllocated, MemoryAllocated	What is already committed to execution environments

Execution environment (function version) level

Metric (names per AWS)	Use
ExecutionEnvironmentConcurrency	Observed concurrency (sampled over a window per AWS)
ExecutionEnvironmentConcurrencyLimit	Ceiling per environment you configured
ExecutionEnvironmentCPUUtilization, ExecutionEnvironmentMemoryUtilization	Whether that version is sized correctly

Cadence and retention

Per AWS, LMI metrics are published on 5-minute intervals and retained 15 months — plan dashboards and alarms around that granularity.

See also

Elasticity & CPU How CPU-linked scaling relates to the fleet metrics above.

Concurrency & runtimes What execution environments are before you interpret concurrency metrics.

Quotas Service and throughput limits that interact with observed load.