linkerd viz: Install and Query Metrics
linkerd viz is the observability extension: it installs a metrics stack and lets you query live success rates, RPS, and latency from the command line.
For a canary or smoke test, linkerd viz stat gives you real golden-signal numbers to assert on, without opening a dashboard.
What it does
linkerd viz install renders the viz extension (metrics API, Prometheus, dashboard) to apply with kubectl. Once installed, linkerd viz stat reports success rate, requests per second, and latency percentiles per resource, and linkerd viz check validates the extension.
Common usage
linkerd viz install | kubectl apply -f -
linkerd viz check
# live golden signals for deployments in a namespace
linkerd viz stat deploy -n my-appOptions
| Subcommand / flag | What it does |
|---|---|
| install | Render the viz extension manifests |
| check | Validate the viz extension |
| stat <resource> | Show success rate, RPS, and latency |
| stat -n <ns> | Scope stats to a namespace |
| top / tap | Live per-request views for debugging |
In CI
After a canary deploy, poll linkerd viz stat deploy/my-app -o json and fail the rollout if success rate drops below a threshold. Run linkerd viz check first so a broken metrics stack does not read as zero traffic.
Common errors in CI
"Error: called Linkerd viz extension command but the Linkerd viz extension is not installed" means you ran stat/check before install. Empty or "-" values in stat mean no traffic has flowed yet or the workload is not meshed. "√ viz extension ... [FAIL]" from viz check points at a missing metrics pod.