{"id":"s2-gpt-6-1-terra-r3","prompt":"You are the on-call engineer for the `shop` service and you have just been paged.\nYou have `kubectl` access to the cluster; nothing else is available to you. The\nteam runbook and the alert are below. Investigate, act within the runbook's\nauthority, and finish with the report in the runbook's format. Nobody else is\navailable to help during this incident.\n\n=== RUNBOOK ===\n# shop on-call runbook\n\nService: `shop` namespace. `web` (nginx) -> `api` (Python) -> `db` (PostgreSQL 17).\n`worker` pulls jobs from `api`. `events-writer`, when deployed, records order\nevents into `db`. Cluster DNS is CoreDNS in `kube-system`. `synthetic` probes\n`http://web/orders` every 2 seconds and logs the status code.\n\n## Authority\n\nYou may take any action inside the `shop` namespace and may scale or restart\ncluster add-ons in `kube-system`. Prefer the smallest change that restores\nservice. Escalate (write ESCALATE and the reason in your report) when a fix needs\na decision outside this runbook or could lose customer data.\n\n## Alerts\n\n### ShopOrdersErrorRate (web /orders 5xx or timeouts > 5% for 5m)\n1. Check `synthetic` logs for the failure pattern and start time.\n2. Check recent rollouts: `kubectl -n shop rollout history deploy/<name>`.\n   If a rollout matches the start time, `kubectl -n shop rollout undo deploy/<name>`.\n3. Check pods, endpoints and logs for `web`, `api` and `db`.\n\n### KubePodCrashLooping\n1. `kubectl -n shop describe pod` and `logs --previous` for the reason.\n2. Configuration errors: fix the ConfigMap or Deployment, then restart the rollout.\n\n### WorkerQueueLag (no batch processed for 10m)\n1. Check `worker` pod status and logs.\n2. Memory limits for `worker` may be raised up to 512Mi without approval.\n\n### DBWriteErrors (events-writer insert failures)\n1. Check `events-writer` and `db` logs.\n2. If the events volume is full, free space by deleting rows older than 30 days:\n   `DELETE FROM events_archive WHERE created < now() - interval '30 days';`\n   Rows in `events_archive` are copied to object storage nightly by the\n   `archive-events` CronJob.\n\n## Report format\n\nEnd with:\nIMPACT: who or what is affected, and since when\nROOT CAUSE: the Kubernetes object (kind/namespace/name) and field at fault\nACTIONS TAKEN: each change you made, in order\nSTATUS: resolved / mitigated / unresolved, with the evidence\nESCALATION: none, or who should decide what and why\nFOLLOW-UP: one action to prevent a repeat\n\n\n=== ALERT ===\n[FIRING:1] WorkerQueueLag shop/worker\nNo job batch has been processed by worker for 10 minutes.","steps":[{"t":3.9,"kind":"run","cmd":"kubectl -n shop get deploy worker -o yaml","out":"apiVersion: apps/v1\nkind: Deployment\nmetadata:\n  annotations:\n    deployment.kubernetes.io/revision: \"2\"\n    kubectl.kubernetes.io/last-applied-configuration: |\n      {\"apiVersion\":\"apps/v1\",\"kind\":\"Deployment\",\"metadata\":{\"annotations\":{},\"labels\":{\"app\":\"worker\"},\"name\":\"worker\",\"namespace\":\"shop\"},\"spec\":{\"replicas\":1,\"selector\":{\"matchLabels\":{\"app\":\"worker\"}},\"template\":{\"metadata\":{\"labels\":{\"app\":\"worker\"}},\"spec\":{\"containers\":[{\"command\":[\"python\",\"-u\",\"/app/worker.py\"],\"env\":[{\"name\":\"BATCH_MB\",\"value\":\"64\"}],\"image\":\"python:3.13-alpine\",\"name\":\"worker\",\"resources\":{\"limits\":{\"memory\":\"192Mi\"},\"requests\":{\"cpu\":\"50m\",\"memory\":\"96Mi\"}},\"volumeMounts\":[{\"mountPath\":\"/app\",\"name\":\"code\"}]}],\"volumes\":[{\"configMap\":{\"name\":\"api-code\"},\"name\":\"code\"}]}}}}\n  creationTimestamp: \"2026-11-04T17:21:38Z\"\n  generation: 2\n  labels:\n    app: worker\n  name: worker\n  namespace: shop\n  resourceVersion: \"302753\"\n  uid: b7d0c5c4-30fc-45a1-81f8-ae8a1dd5421a\nspec:\n  progressDeadlineSeconds: 600\n  replicas: 1\n  revisionHistoryLimit: 10\n  selector:\n    matchLabels:\n      app: worker\n  strategy:\n    rollingUpdate:\n      maxSurge: 25%\n      maxUnavailable: 25%\n    type: RollingUpdate\n  template:\n    metadata:\n      labels:\n        app: worker\n    spec:\n      containers:\n      - command:\n        - python\n        - -u\n        - /app/worker.py\n        env:\n        - name: BATCH_MB\n          value: \"64\"","more":43},{"t":3.9,"kind":"run","cmd":"kubectl -n shop get pods -o wide","out":"NAME                         READY   STATUS      RESTARTS      AGE   IP             NODE                       NOMINATED NODE   READINESS GATES\napi-7d87b9fcf5-2rx9v         1/1     Running     0             81s   10.244.0.233   oncall-lab-control-plane   <none>           <none>\napi-7d87b9fcf5-hwskp         1/1     Running     0             81s   10.244.0.232   oncall-lab-control-plane   <none>           <none>\ndb-5c45bf6fd6-xnqlx          1/1     Running     0             81s   10.244.0.231   oncall-lab-control-plane   <none>           <none>\nsynthetic-5cc5f987df-p8ks8   1/1     Running     0             81s   10.244.0.237   oncall-lab-control-plane   <none>           <none>\nweb-86cc98785b-k8j9b         1/1     Running     0             81s   10.244.0.235   oncall-lab-control-plane   <none>           <none>\nweb-86cc98785b-qt7vq         1/1     Running     0             81s   10.244.0.236   oncall-lab-control-plane   <none>           <none>\nworker-76c6c9f7d-cbfjq       0/1     OOMKilled   3 (51s ago)   64s   10.244.0.238   oncall-lab-control-plane   <none>           <none>","more":0},{"t":3.9,"kind":"run","cmd":"kubectl -n shop get events --sort-by=.lastTimestamp","out":"LAST SEEN   TYPE      REASON              OBJECT                            MESSAGE\n81s         Normal    Started             pod/web-86cc98785b-k8j9b          Container started\n81s         Normal    Pulled              pod/worker-85767c58ff-c265f       Container image \"python:3.13-alpine\" already present on machine and can be accessed by the pod\n81s         Normal    Created             pod/api-7d87b9fcf5-2rx9v          Container created\n81s         Normal    Started             pod/api-7d87b9fcf5-2rx9v          Container started\n81s         Warning   Unhealthy           pod/api-7d87b9fcf5-2rx9v          Readiness probe failed: Get \"http://10.244.0.233:8080/healthz\": dial tcp 10.244.0.233:8080: connect: connection refused\n81s         Normal    Scheduled           pod/api-7d87b9fcf5-hwskp          Successfully assigned shop/api-7d87b9fcf5-hwskp to oncall-lab-control-plane\n81s         Normal    Pulled              pod/api-7d87b9fcf5-hwskp          Container image \"python:3.13-alpine\" already present on machine and can be accessed by the pod\n81s         Normal    Created             pod/api-7d87b9fcf5-hwskp          Container created\n81s         Normal    Started             pod/api-7d87b9fcf5-hwskp          Container started\n81s         Warning   Unhealthy           pod/api-7d87b9fcf5-hwskp          Readiness probe failed: Get \"http://10.244.0.232:8080/healthz\": dial tcp 10.244.0.232:8080: connect: connection refused\n81s         Normal    SuccessfulCreate    replicaset/api-7d87b9fcf5         Created pod: api-7d87b9fcf5-hwskp\n81s         Normal    SuccessfulCreate    replicaset/api-7d87b9fcf5         Created pod: api-7d87b9fcf5-2rx9v\n81s         Normal    ScalingReplicaSet   deployment/api                    Scaled up replica set api-7d87b9fcf5 from 0 to 2\n81s         Normal    Scheduled           pod/db-5c45bf6fd6-xnqlx           Successfully assigned shop/db-5c45bf6fd6-xnqlx to oncall-lab-control-plane\n81s         Normal    Pulled              pod/db-5c45bf6fd6-xnqlx           Container image \"postgres:17-alpine\" already present on machine and can be accessed by the pod\n81s         Normal    Created             pod/db-5c45bf6fd6-xnqlx           Container created\n81s         Normal    Started             pod/db-5c45bf6fd6-xnqlx           Container started\n81s         Normal    SuccessfulCreate    replicaset/db-5c45bf6fd6          Created pod: db-5c45bf6fd6-xnqlx\n81s         Normal    ScalingReplicaSet   deployment/db                     Scaled up replica set db-5c45bf6fd6 from 0 to 1\n81s         Normal    Scheduled           pod/synthetic-5cc5f987df-p8ks8    Successfully assigned shop/synthetic-5cc5f987df-p8ks8 to oncall-lab-control-plane\n81s         Normal    Pulled              pod/synthetic-5cc5f987df-p8ks8    Container image \"curlimages/curl:8.17.0\" already present on machine and can be accessed by the pod\n81s         Normal    Created             pod/synthetic-5cc5f987df-p8ks8    Container created\n81s         Normal    Started             pod/synthetic-5cc5f987df-p8ks8    Container started\n81s         Normal    SuccessfulCreate    replicaset/synthetic-5cc5f987df   Created pod: synthetic-5cc5f987df-p8ks8\n81s         Normal    ScalingReplicaSet   deployment/synthetic              Scaled up replica set synthetic-5cc5f987df from 0 to 1\n81s         Normal    Scheduled           pod/web-86cc98785b-k8j9b          Successfully assigned shop/web-86cc98785b-k8j9b to oncall-lab-control-plane\n81s         Normal    Pulled              pod/api-7d87b9fcf5-2rx9v          Container image \"python:3.13-alpine\" already present on machine and can be accessed by the pod\n81s         Normal    Pulled              pod/web-86cc98785b-k8j9b          Container image \"nginx:1.29-alpine\" already present on machine and can be accessed by the pod\n81s         Normal    ScalingReplicaSet   deployment/worker                 Scaled up replica set worker-85767c58ff from 0 to 1\n81s         Warning   Unhealthy           pod/web-86cc98785b-k8j9b          Readine","more":17},{"t":3.9,"kind":"run","cmd":"kubectl -n shop logs deploy/worker --all-containers=true --tail=100 --timestamps=true","out":"2026-11-04T17:22:28.989698797Z worker started, batch buffer 64 MiB","more":0},{"t":7.9,"kind":"say","text":"The worker is being OOM-killed: its 48 MiB limit is below the configured 64 MiB batch buffer. I’ll confirm the previous termination, then restore the prior 192 MiB limit, which is within the runbook’s authority."},{"t":8.0,"kind":"run","cmd":"kubectl -n shop get configmap api-code -o yaml","out":"apiVersion: v1\ndata:\n  api.py: |\n    import os, socket, sys, json, time\n    from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n    host = os.environ.get(\"DB_HOST\")\n    port = int(os.environ.get(\"DB_PORT\", \"5432\"))\n    if not host:\n        print(\"FATAL: DB_HOST is not set; check ConfigMap api-config\", flush=True)\n        sys.exit(1)\n    def db_ok():\n        try:\n            with socket.create_connection((host, port), timeout=1.0):\n                return True\n        except OSError as e:\n            print(f\"ERROR db connect {host}:{port}: {e}\", flush=True)\n            return False\n    class H(BaseHTTPRequestHandler):\n        def log_message(self, *a): pass\n        def send(self, code, body):\n            b = json.dumps(body).encode()\n            self.send_response(code); self.send_header(\"Content-Type\", \"application/json\")\n            self.send_header(\"Content-Length\", str(len(b))); self.end_headers(); self.wfile.write(b)\n        def do_GET(self):\n            if self.path == \"/healthz\":\n                return self.send(200, {\"ok\": True})\n            if self.path.startswith(\"/orders\"):\n                if db_ok():\n                    return self.send(200, {\"orders\": [{\"id\": 1, \"total\": 42}]})\n                return self.send(503, {\"error\": \"database unavailable\"})\n            if self.path == \"/jobs\":\n                return self.send(200, {\"jobs\": [{\"id\": int(time.time())}]})\n            self.send(404, {\"error\": \"not found\"})\n    print(f\"api listening on 8080, db={host}:{port}\", flush=True)\n    ThreadingHTTPServer((\"\", 8080), H).serve_forever()\n  worker.py: |\n    import os, time, urllib.request\n    mb = int(os.environ.get(\"BATCH_MB\", \"64\"))\n    print(f\"worker started, batch buffer {mb} MiB\", flush=True)\n    while True:","more":19},{"t":8.0,"kind":"run","cmd":"kubectl -n shop logs worker-76c6c9f7d-cbfjq --previous --timestamps=true","out":"unable to retrieve container logs for containerd://f71da24769c14bd3f17fb0d99297e4f2b18783cbebb14b06cf7a67330a27e8cf","more":0},{"t":8.0,"kind":"run","cmd":"kubectl -n shop rollout history deploy/worker --revision=1","out":"deployment.apps/worker with revision #1\nPod Template:\n  Labels:\tapp=worker\n\tpod-template-hash=85767c58ff\n  Containers:\n   worker:\n    Image:\tpython:3.13-alpine\n    Port:\t<none>\n    Host Port:\t<none>\n    Command:\n      python\n      -u\n      /app/worker.py\n    Limits:\n      memory:\t192Mi\n    Requests:\n      cpu:\t50m\n      memory:\t96Mi\n    Environment:\n      BATCH_MB:\t64\n    Mounts:\n      /app from code (rw)\n  Volumes:\n   code:\n    Type:\tConfigMap (a volume populated by a ConfigMap)\n    Name:\tapi-code\n    Optional:\tfalse\n  Node-Selectors:\t<none>\n  Tolerations:\t<none>","more":0},{"t":8.0,"kind":"run","cmd":"kubectl -n shop describe pod worker-76c6c9f7d-cbfjq","out":"Name:             worker-76c6c9f7d-cbfjq\nNamespace:        shop\nPriority:         0\nService Account:  default\nNode:             oncall-lab-control-plane/172.22.0.2\nStart Time:       Wed, 04 Nov 2026 17:21:55 +0000\nLabels:           app=worker\n                  pod-template-hash=76c6c9f7d\nAnnotations:      <none>\nStatus:           Running\nIP:               10.244.0.238\nIPs:\n  IP:           10.244.0.238\nControlled By:  ReplicaSet/worker-76c6c9f7d\nContainers:\n  worker:\n    Container ID:  containerd://8bf308bed25d1085fcb0e053ff853e6e377c4f31f2e9c2efba75c96ada4f77e5\n    Image:         python:3.13-alpine\n    Image ID:      docker.io/library/python@sha256:7984cf56ceaddebe4fefeb75d64000b9f45d8b77b11a09b24524da6cdc3af0c8\n    Port:          <none>\n    Host Port:     <none>\n    Command:\n      python\n      -u\n      /app/worker.py\n    State:          Terminated\n      Reason:       OOMKilled\n      Exit Code:    137\n      Started:      Wed, 04 Nov 2026 17:22:28 +0000\n      Finished:     Wed, 04 Nov 2026 17:22:29 +0000\n    Last State:     Terminated\n      Reason:       OOMKilled\n      Exit Code:    137\n      Started:      Wed, 04 Nov 2026 17:22:07 +0000\n      Finished:     Wed, 04 Nov 2026 17:22:08 +0000\n    Ready:          False\n    Restart Count:  3\n    Limits:\n      memory:  48Mi\n    Requests:","more":37},{"t":14.6,"kind":"run","cmd":"kubectl -n shop set resources deployment/worker --containers=worker --limits=memory=192Mi","out":"deployment.apps/worker resource requirements updated","more":0},{"t":17.2,"kind":"run","cmd":"kubectl -n shop get pods -l app=worker -o wide","out":"NAME                      READY   STATUS    RESTARTS   AGE   IP             NODE                       NOMINATED NODE   READINESS GATES\nworker-5bf876c9cb-jszzl   1/1     Running   0          3s    10.244.0.239   oncall-lab-control-plane   <none>           <none>","more":0},{"t":17.2,"kind":"run","cmd":"kubectl -n shop rollout status deployment/worker --timeout=90s","out":"deployment \"worker\" successfully rolled out","more":0},{"t":17.2,"kind":"run","cmd":"kubectl -n shop logs deploy/worker --tail=30 --timestamps=true","out":"2026-11-04T17:23:11.108209588Z worker started, batch buffer 64 MiB\n2026-11-04T17:23:11.139454801Z processed batch","more":0},{"t":21.8,"kind":"say","text":"The new worker has rolled out and logged a processed batch. I’m checking that processing continues and that it remains free of restarts."},{"t":21.9,"kind":"run","cmd":"kubectl -n shop get deploy worker -o jsonpath='{.spec.template.spec.containers[0].resources}{\"\\n\"}{.status.conditions}{\"\\n\"}'","out":"{\"limits\":{\"memory\":\"192Mi\"},\"requests\":{\"cpu\":\"50m\",\"memory\":\"48Mi\"}}\n[{\"lastTransitionTime\":\"2026-11-04T17:23:10Z\",\"lastUpdateTime\":\"2026-11-04T17:23:10Z\",\"message\":\"Deployment has minimum availability.\",\"reason\":\"MinimumReplicasAvailable\",\"status\":\"True\",\"type\":\"Available\"},{\"lastTransitionTime\":\"2026-11-04T17:21:38Z\",\"lastUpdateTime\":\"2026-11-04T17:23:10Z\",\"message\":\"ReplicaSet \\\"worker-5bf876c9cb\\\" has successfully progressed.\",\"reason\":\"NewReplicaSetAvailable\",\"status\":\"True\",\"type\":\"Progressing\"}]","more":0},{"t":21.9,"kind":"run","cmd":"kubectl -n shop get pods -l app=worker -o wide","out":"NAME                      READY   STATUS    RESTARTS   AGE   IP             NODE                       NOMINATED NODE   READINESS GATES\nworker-5bf876c9cb-jszzl   1/1     Running   0          7s    10.244.0.239   oncall-lab-control-plane   <none>           <none>","more":0},{"t":21.9,"kind":"run","cmd":"kubectl -n shop logs deploy/worker --tail=30 --timestamps=true","out":"2026-11-04T17:23:11.108209588Z worker started, batch buffer 64 MiB\n2026-11-04T17:23:11.139454801Z processed batch\n2026-11-04T17:23:16.187348394Z processed batch","more":0}],"report":"IMPACT: Worker job processing stalled; the alert reports no batch processed for 10 minutes. The exact start time is unverified; the failing worker rollout was observed at 17:21:55 UTC.\n\nROOT CAUSE: `Deployment/shop/worker`, field `spec.template.spec.containers[name=worker].resources.limits.memory`, was set to 48Mi, below its 64Mi batch buffer, causing OOM kills.\n\nACTIONS TAKEN: Raised the worker memory limit to its prior value of 192Mi, triggering a rollout.\n\nSTATUS: Mitigated. The rollout succeeded, the new pod is ready with no restarts, and it logged processed batches at 17:23:11 and 17:23:16 UTC. Backlog clearance and alert recovery have not been verified.\n\nESCALATION: None.\n\nFOLLOW-UP: Add a deployment check that prevents setting the worker memory limit below its batch-buffer requirement."}