observability-sre-triage

# SRE Service Triage Decide whether a service is healthy, degraded, or unhealthy, and say why. Triage is a hierarchy, not a checklist: SLOs and alerts define whether the service is failing its contract, trace-derived golden signals describe how it is failing, dependencies and infrastructure explain where the failure comes from, and logs supply the sentence you put in the incident channel. Work down the hierarchy until the evidence supports a verdict, then stop. For authoring and tuning SLO definitions, burn-rate rules, and alert thresholds, use the **observability-service-reliability** skill. This skill only reads that state. For Kubernetes workload, node, or control-plane diagnosis — restart loops, OOM kill confirmation, node pressure, admission rejections, stuck rollouts — hand off to the **observability-k8s-investigation** skill. This skill checks whether a Kubernetes-hosted service is saturated; it does not diagnose why the pod or the node behind it is failing. <!-- begin-partial: preamble --> ## Environment Configuration This skill executes Elasticsearch operations through the `elastic` CLI. If the [`elastic` CLI](https://github.com/elastic/cli#configuration) is not installed, tell the user what it is needed for. Do not guess credentials, call the HTTP API directly, or attempt other workarounds. This skill references operations in HTTP-shorthand form (e.g., `GET /`, `GET /_cat/indices`, `GET /{index}/_mapping`, `GET /{index}/_settings/index.mode`, `POST /_query`). The [Operations](#operations) table at the end of this document maps each shorthand to the equivalent `elastic` CLI command — always use the CLI rather than calling the HTTP API directly. <!-- end-partial: preamble --> ### Analysis without cluster access The CLI check above gates _querying the cluster_ — it does not gate analysis. When the user has already supplied the evidence in their question (metric values, counts, status reasons, log lines, alert payloads, configuration), reason from that evidence and deliver the conclusion. When you genuinely do need data the user has not provided, still say what you would check and how — name the specific query, index, and field that would settle the question — and then ask for CLI setup. An answer that names the check is useful without a cluster; one that only asks for setup is not. Everything here is expressed in ES|QL (`POST /_query`) or the Kibana Observability APIs. Do not use Query DSL, and do not use the ES|QL `KQL` search function — express predicates natively (`WHERE service.name == "checkout"`). ## Jobs to be done - Answer "is service X healthy?" with a verdict and the evidence behind it - Answer "why is service X slow / erroring / quiet?" by localizing the change to the service, a dependency, or its infrastructure - Read SLO status, burn rate, and remaining error budget during an incident - Determine which alerting rules currently apply to a service, including all-services rules - Funnel a noisy log stream down to the failures that explain the degradation - Identify which attribute (version, host, pod, region, route) distinguishes the failing or slow subpopulation - Distinguish a healthy service from a service with no telemetry ## Output discipline Applies to every response produced under this skill. - **Commit to the best-supported conclusion.** When the evidence points one way, say so. Do not downgrade confidence to sound cautious — hedging on unambiguous evidence is a defect, not humility. - **Commit to a verdict**: healthy, degraded, or unhealthy, followed by the reason. A triage answer that does not name one of the three has not done the job. - **State confidence once**, in the conclusion. Do not restate it per bullet. - **Do not speculate past the evidence.** If the telemetry did not show a cause, it does not go in the answer. Name what is unknown and stop. Never offer a mechanism ("probably a GC pause", "likely a noisy neighbor") that no signal measured. - **Report absence as absence.** Zero rows means the data is missing or not collected; it never means the underlying condition is healthy. "No dependency metrics" is not "dependencies are fine". - **Do not pad.** No restating the question, no narrating which queries were run unless the result mattered, no summarizing the summary. - **End on the finding.** No trailing offers such as "want me to dig deeper?". Actionable follow-ups belong in a recommendations list, phrased as recommendations, not as questions. ## Signal hierarchy Signals disagree constantly. This ordering decides which one wins. | Rank | Signal | Authority | | ---- | ------------------------------------- | ------------------------------------------------------------------------------------------- | | 1 | **SLO status and burn rate** | Authoritative when SLOs exist. They encode the agreed definition of "good" for this service | | 2 | **Active alerting rules** | Authoritative when no SLO covers the symptom. Sourced from the Alerting API | | 3 | **Error rate, latency, throughput** | Describes the degradation. Decisive only when nothing above it exists | | 4 | **Dependency health** | Locates the cause upstream or downstream; does not by itself set the verdict | | 5 | **ML anomalies** | Deviation from learned baseline, not from a target. Corroborates and time-bounds | | 6 | **Infrastructure (CPU, memory, OOM)** | Explains a mechanism. A saturated pod with healthy golden signals is a risk, not an outage | | 7 | **Logs** | Explain, never decide. Log volume is not health | Conflict rules: - **SLO healthy, latency elevated** → degraded but within error budget. The verdict follows the SLO; report the trend as a risk with the burn rate. - **SLO violated, current-window metrics look fine** → trust the SLO and check its window. SLOs are evaluated over hours or days; a 15-minute ES|QL window can look clean while the budget is already spent. - **Alerts firing, no SLO defined** → the alerts are the verdict. Resolve each rule's `params` to confirm it actually targets this service before attributing it. - **Logs noisy, golden signals flat** → not degraded. High log volume without an error-rate or latency change is a logging-configuration finding, not a health finding. - **Throughput collapsed, error rate flat** → the caller stopped calling. Look upstream before blaming this service. - **Any query returns zero rows** → missing data. Say which signal is unavailable and lower the scope of the verdict accordingly; never convert silence into health. ## Routing: symptom to first signal | Presenting symptom | Pull first | Reference | | --------------------------------------- | -------------------------------------------------------------------- | ------------------------------------------------------- | | "Is X healthy?" / unclear | SLO status, then active rules, then golden signals | [slo-and-alerts.md](references/slo-and-alerts.md) | | "X is slow" | Latency percentiles versus the prior period, then dependency latency | [apm-signals.md](references/apm-signals.md) | | "X is erroring" / 5xx | Error rate by route, then failed-transaction correlation | [apm-signals.md](references/apm-signals.md) | | "X is down" / no traffic | Throughput, then confirm the service still ingests at all | [apm-signals.md](references/apm-signals.md) | | "Only some requests are bad" | Subpopulation correlation over candidate attributes | [apm-signals.md](references/apm-signals.md) | | "An alert fired" / "the SLO is burning" | Rule `params` and SLO burn rate, then the metric the rule watches | [slo-and-alerts.md](references/slo-and-alerts.md) | | "What is in the logs?" / noisy logs | The log funnel — iterate with `NOT` exclusions | [log-investigation.md](references/log-investigation.md) | | Suspected OOM, throttling, restarts | Container CPU and memory limit utilization | [apm-signals.md](references/apm-signals.md) | | "Is it saturated?" on a non-K8s host | Host CPU, memory, and load average from the hostmetrics receiver | [apm-signals.md](references/apm-signals.md) | | "Which downstream is hurting X?" | Per-destination call volume, latency, and failure rate | [apm-signals.md](references/apm-signals.md) | ## Data sources OTel-native data streams, verified against Elasticsearch 9.6.0: | Data | Index pattern | | ----------------------------- | ----------------------------------------------------------------------------------------------------------- | | Traces (spans, transactions) | `traces-*.otel-*`; classic Elastic APM agent ingest also lands in `traces*apm*` | | Logs | `logs-*.otel-*` | | Raw metrics | `metrics-*.otel-*`; classic APM agent ingest also lands in `metrics*apm*` | | Service inventory (1m rollup) | `metrics-service_summary.1m.otel-*` | | Transaction rollups (1m) | `metrics-service_transaction.1m.otel-*`, `metrics-transaction.1m.otel-*` | | Dependency rollups (1m) | `metrics-service_destination.1m.otel-*` | | Kubernetes | `metrics-kubeletstatsreceiver.otel-*`, `metrics-k8sclusterreceiver.otel-*`, `logs-k8seventsreceiver.otel-*` | | Host (VM, bare metal) | `metrics-hostmetricsreceiver.otel-*`; the Elastic Agent system integration lands in `metrics-system.*` | `service.name` is populated on traces, metrics, and logs, so it is the join key across all three. Use flat OTel field paths in ES|QL (`k8s.pod.name`, not `resource.attributes.k8s.pod.name`). When analyzing OTel application metrics, the ES|QL `TS` (time series) command gives more efficient metric queries. It is GA on Serverless; on Stack it is preview in 9.2 and GA in 9.4, so below 9.4 use `FROM` with `BUCKET` instead. `TS` also rejects `COUNT(*)` — count a field instead. The recipes in this skill and its references are written against the OTel-native streams above. A service instrumented with the classic Elastic APM agent ships to `traces-apm*` and `metrics-apm*` under different field names (`transaction.duration.us`, `event.outcome`), so these recipes return no rows for it. An empty result on a service that is otherwise clearly alive is therefore a scope boundary, not evidence of an outage: check which index family the service actually writes (`GET /_cat/indices`) and report the ingest path rather than concluding from silence. ## ES|QL feature availability Three features this skill uses are newer than its 8.11 base floor. Check `GET /` before relying on them: `build_flavor: "serverless"` means all three are available; otherwise compare `version.number` against the Stack column. Never report "no data" when the real answer is that the query did not run — say which feature was unavailable and use the fallback. | Feature | Serverless | Stack | Licence | Used by | Fallback | | ------------ | ---------- | ------------------------ | ------------ | ------------------------------------------------ | ------------------------------------------------------------------------- | | `FORK` | GA | preview 9.1-9.3, GA 9.4+ | any | The log funnel, and the subpopulation comparison | Run each branch as a separate query and combine the results yourself | | `CATEGORIZE` | GA | preview 9.0, GA 9.1 | **Platinum** | Message categorization inside the log funnel | Group by a truncated message prefix, or funnel on structured error fields | | `TS` | GA | preview 9.2, GA 9.4 | any | OTel application metric queries | `FROM` with `BUCKET` over the same data stream | The Platinum requirement on `CATEGORIZE` is not a version check. A 9.6 Stack cluster on a Basic or Gold licence fails it exactly as an 8.11 cluster fails `FORK`, and the error names the licence rather than the syntax. On Serverless the function is GA with no separate licence gate. ## Process: triage a degraded service 1. **Fix the service and the window.** Resolve the service name and the time range from the request. Use the user's time range — do not silently assume the last hour when the complaint is historical. If no range is given, use the last hour and say so. Confirm the service actually exists in telemetry with a `COUNT(*) BY service.name` over `traces-*.otel-*` via `POST /_query`; if the name does not appear, resolve the ambiguity before querying further. Decision: which service and window every later query is scoped to. Data: distinct `service.name` values in range. 2. **Read SLO status and burn rate.** List SLOs with `GET kbn:/api/observability/slos` and fetch the ones bound to this service with `GET kbn:/api/observability/slos/{id}`. Read status, current SLI, burn rate, and remaining error budget. Decision: does an agreed contract exist, and is it being violated? If yes, the verdict is already determined and the remaining steps only explain it. If no SLO covers this service, say so once and fall through to step 3. 3. **Determine which alerting rules apply to this service, and which of them are firing.** Call `GET kbn:/api/alerting/rules/_find` with `per_page=100&filter=alert.attributes.enabled:true`, paging with `page` if `total` exceeds what you received. Then filter the response **client-side**. **Do not query `.alerts*` indices to determine active state** — the Alerting API response is the source of truth. Fetch a rule's full definition with `GET kbn:/api/alerting/rule/{id}` when its `params` are needed. **Do not narrow this call server-side.** The `_find` `filter` parameter is KQL over saved-object _attributes_, and `params` is not among them — `filter=alert.attributes.params.serviceName:<name>` returns zero rules on a cluster that has them. Narrowing by `search=apm&search_fields=tags`, by `alertTypeId`, or by `consumer` is worse: it drops rules on a naming convention or a rule-type allowlist, and the rules it drops are disproportionately the all-services ones. See [references/slo-and-alerts.md](references/slo-and-alerts.md) for the measured failure. From the fetched set, evaluate **both** rules whose `params.serviceName` matches the service **and** rules where `params.serviceName` is absent, because the latter are all-services rules that apply to it too. Read `execution_status.status` on each: `active` means the rule's last run produced alerts, `ok` means it ran and produced none, and `error` means it is not evaluating at all — a blind spot, not a pass. Decision: what covers this service, and is any of it currently firing? Data: rule `params.serviceName`, rule type, and execution status. 4. **Check ML anomalies, if any jobs exist.** List jobs with `GET /_ml/anomaly_detectors` and confirm they are running