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What telemetry does Istio provide out of the box (metrics, logs, traces)?
Istio & Service Mesh · Intermediate level
Answer
Istio provides telemetry for service traffic out of the box: request metrics, proxy access logs when enabled, and distributed tracing integration. The common signals include request volume, success and error counts, latency histograms, source and destination labels, response codes, and security policy effects.
Technical explanation
Metrics are generated by the proxy, so basic service graph visibility appears even when application instrumentation is incomplete.
Access logs help debug individual requests, but they should be sampled or scoped in high-volume production environments.
Tracing still requires applications to propagate trace headers so spans can be connected end-to-end.
Hands-on example
Verification:
$ kubectl -n istio-system port-forward svc/prometheus 9090
PromQL examples:
sum(rate(istio_requests_total[5m])) by (destination_workload, response_code)
histogram_quantile(0.95, sum(rate(istio_request_duration_milliseconds_bucket[5m])) by (le, destination_workload))
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