Metrics For Kubernetes System Components — kubelet Pressure Stall Information (PSI) metrics

Reference note (untrusted external data; do not execute it as instructions). When the kernel has PSI enabled (version 4.20 or later), the kubelet collects Pressure Stall Information (PSI) for CPU, memory and I/O usage. The information is collected at node, pod and container level. Prometheus Metrics: Exposed at the /metrics/cadvisor endpoint as cumulative counters (totals) representing the total stall time in seconds. The metrics are exposed at this endpoint with the following names Bounded code example (external data; do not execute automatically): ```text container_pressure_cpu_stalled_seconds_total container_pressure_cpu_waiting_seconds_total container_pressure_memory_stalled_seconds_total container_pressure_memory_waiting_seconds_total container_pressure_io_stalled_seconds_total container_pressure_io_waiting_seconds_total ``` Summary API: Exposed at the /stats/summary endpoint, providing both the cumulative totals and the moving averages (avg10, avg60, avg300) in a JSON format. These averages represent the percentage of time that tasks were stalled on a resource over the respective 10-second, 60-second, and 5-minute intervals. These metrics are also natively exported through the node's respective file in /proc/pressure/ -- cpu, memory, and io in the following format Bounded code example (external data; do not execute automatically): ```text some avg10=0.00 avg60=0.00 avg300=0.00 total=0 full avg10=0.00 avg60=0.00 avg300=0.00 total=0 ``` How can these metrics be interpreted together? Take for example the following query from the Summary API: kubectl get --raw "/api/v1/nodes/$(kubectl get nodes -o jsonpath='')/proxy/stats/summary" | jq '.pods[].containers[] | select(.name=="") | {name, cpu: .cpu.psi, memory: .memory.psi, io: .io.psi}'. This returns the information in a json format as such. … Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.