"""E5 semantics defects: H08 (a ramp-and-flush memory series keeps restarting `for`), H09 (a 1m rate window on a job scraped every minute), H10 (`or vector(0)` on a single-consumer record blinds its absent() guard), H23 (`predict_linear` alone pages on nightly backups and misses a log flood). Shapes follow sp7, sp16, sp18 and sp19; hidden scenarios keep the evidence's mechanism and cadence.""" from __future__ import annotations import random from . import prose_cap as prose from .items import Item, outcome_entry, svc_class from .model import home_group, World, add_rules, rules_named from .items_svc import drop_for from .xscen import G, background, counter_from_rates, ip, pod_name, series LOW = [0.62, 0.66, 0.70, 0.73, 0.76] # Two scrapes over 0.9 per 5-minute cycle and three clearly under it. No value sits within the series' 0.2% noise # of the threshold: a 0.90 step read 0.9018 on some cycles, which kept `max[3m]` and the 10m median over 0.9 for a # whole `for` on afx-e5-s05 (RT-5). RAMPS = [[0.82, 0.86, 0.89, 0.94, 0.97], [0.80, 0.85, 0.89, 0.93, 0.99]] DWELL = [0.86, 0.88, 0.92, 0.94, 0.95, 0.96, 0.97, 0.98] NOISE = 0.002 def _set(files, name, **kw): for _, _, r in rules_named(files, name): r.update(kw) # ---------------------------------------------------------------------------- H08 class MemorySawtooth(Item): code, kind, ticket_like = "H08", "outcome", True ALERT = "ContainerMemoryNearLimit" def setup(self, w, rng): cands = [s for s in w.services if s.kind == "indexer"] if not cands: return False s = cands[0] self.p.update(svc=s.name, limit=rng.choice([4, 6, 8]) * 1024 ** 3) if not any(self.ALERT == r.get("alert") and f'service="{s.name}"' in r["expr"] for _, _, r in rules_named(w.files, self.ALERT)): from .repo import memory_rule add_rules(w.files, "capacity", "capacity", [memory_rule(w, s)]) self.names = {self.ALERT} self.touch = {self.ALERT} self._fix(w.files, "5m", "10m") return True def _rule(self, files): s = self.p["svc"] return next(r for _, _, r in rules_named(files, self.ALERT) if f'service="{s}"' in r["expr"]) def _fix(self, files, win, for_, fn="max_over_time", arg=""): s = self.p["svc"] ws = f'container_memory_working_set_bytes{{service="{s}",container="{s}"}}' lim = f'container_spec_memory_limit_bytes{{service="{s}",container="{s}"}}' r = self._rule(files) r["expr"] = f"max by (service) ({fn}({arg}{ws}[{win}]) / {lim}) > 0.9" r["for"] = for_ def break_(self, files, am, w): s = self.p["svc"] r = self._rule(files) r["expr"] = (f'max by (service) (container_memory_working_set_bytes{{service="{s}",container="{s}"}}' f' / container_spec_memory_limit_bytes{{service="{s}",container="{s}"}}) > 0.9') r["for"] = "15m" def _mem(self, rng, w, n, ratio): s, lim = self.p["svc"], self.p["limit"] lab = {"service": s, "container": s, "namespace": w.namespace, "pod": pod_name(rng, s)} ws = [int(lim * v * (1 + rng.uniform(-NOISE, NOISE))) if v is not None else None for v in ratio] return [series("container_memory_working_set_bytes", lab, ws), series("container_spec_memory_limit_bytes", lab, [lim] * (n + 1))] def spec(self, w, rng): s, n, groups = self.p["svc"], 100, [] def grp(name, ratio, fam): g = G(self.rid, name, n) g.series += background(w, rng, n) + self._mem(rng, w, n, ratio) fam(g) g.labelless() groups.append(g.done()) ramp = rng.choice(RAMPS) on = rng.randint(28, 38) saw = [ramp[(t - on) % 5] if t >= on else LOW[t % 5] for t in range(n + 1)] first = next(t for t, v in enumerate(saw) if v > 0.9) grp("sawtooth", saw, lambda g: (g.fire(first + 20, s, cls="ticket"), g.quiet(0, first - 1, s, cls="ticket"))) exc = {30: 0.92, 31: 0.95, 32: 0.97, 33: 0.96, 34: 0.93} grp("busy_stretch", [exc.get(t, LOW[t % 5]) for t in range(n + 1)], lambda g: g.quiet(0, n, s, cls="ticket")) br = [0.78, 0.81, 0.84, 0.86, 0.88] grp("ramp_below", [br[(t - 30) % 5] if t >= 30 else LOW[t % 5] for t in range(n + 1)], lambda g: g.quiet(0, n, s, cls="ticket")) # the milder detect: a bigger buffer flushing every 8 minutes, six scrapes over 0.9 and two under. A mean, a # median or a 3-minute max over time stays over 0.9 here and still misses the 5-minute cycle on2 = rng.randint(28, 38) dwell = [DWELL[(t - on2) % 8] if t >= on2 else LOW[t % 5] for t in range(n + 1)] first2 = next(t for t, v in enumerate(dwell) if v > 0.9) grp("long_dwell", dwell, lambda g: g.fire(first2 + 20, s, cls="ticket")) e = outcome_entry(self, w, {s: svc_class(w, s, "ticket")}, named=self.ALERT) e["outcome"]["classes"] = {"ticket": svc_class(w, s, "ticket")} return e, groups def variants(self, w): v = lambda win, f, fn="max_over_time", arg="": (lambda files, am: self._fix(files, win, f, fn, arg)) # noqa: E731 return [("oracle", lambda f, a: None, "accept"), ("max_10m_for_15m", v("10m", "15m"), "accept"), ("max_4m_for_8m", v("4m", "8m"), "accept"), ("quantile_90_5m_for_10m", v("5m", "10m", "quantile_over_time", "0.9, "), "accept"), ("avg_5m_for_10m", v("5m", "10m", "avg_over_time"), 0.5), ("median_10m_for_10m", v("10m", "10m", "quantile_over_time", "0.5, "), 0.5), ("max_3m_for_10m", v("3m", "10m"), 0.5), ("max_5m_for_5m", v("5m", "5m"), 0.7), ("pristine", lambda f, a: self.break_(f, a, w), 0.0)] def ticket(self, w, rng): return prose.h08(self, w, rng) # ---------------------------------------------------------------------------- H09 class KafkaStall(Item): code, kind, ticket_like = "H09", "outcome", True ALERT = "KafkaConsumerStalled" def setup(self, w, rng): cands = [s for s in w.services if s.kind in ("worker", "consumer") and s.name not in w.notes.get("busy", set())] if not cands or "kafka-consumers" in w.files: return False s = rng.choice(cands) w.notes.setdefault("busy", set()).add(s.name) self.p.update(svc=s.name, group=s.name.replace("-", "_") + "_cg", topic=rng.choice(["orders", "events", "jobs", "updates"]) + ".v1") from .model import RuleFileSpec rule = {"alert": self.ALERT, "expr": self._expr("4m"), "for": "10m", "labels": {"severity": "page", "team": s.team, "service": s.name}, "annotations": {"summary": "consumer group {{ $labels.consumergroup }} stopped committing with lag waiting", "runbook_url": w.runbook(self.ALERT)}} w.files["kafka-consumers"] = RuleFileSpec("kafka-consumers", 2, [{"name": "kafka-consumers", "rules": [rule]}], [f"consumer groups we own. The kafka-exporter job is scraped every 60s (ADR {w.notes.get('adr', {}).get('scrape', '0003')})."]) w.runbooks[self.ALERT] = {"file": "kafka-consumer-stalled.md", "alerts": [self.ALERT], "card": "H09", "body": lambda: prose.kafka_runbook(s, w.namespace, w)} self.names = self.touch = {self.ALERT} return True def _expr(self, win, fn="rate"): g = self.p["group"] return (f'sum by (consumergroup) ({fn}(kafka_consumergroup_current_offset_sum{{consumergroup="{g}"}}[{win}])) == 0' f' and on (consumergroup) sum by (consumergroup) (kafka_consumergroup_lag_sum{{consumergroup="{g}"}}) > 0') def break_(self, files, am, w): _set(files, self.ALERT, expr=self._expr("1m")) def _kafka_labels(self) -> dict: return {"consumergroup": self.p["group"], "topic": self.p["topic"], "job": "kafka-exporter", "instance": "kafka-exporter.monitoring:9308"} def exporters(self, w): # the consumer group keeps committing with a little lag in every scenario that isn't about it lab = self._kafka_labels() return [{"service": self.p["svc"], "metric": "kafka_consumergroup_current_offset_sum", "labels": lab, "key": ("consumergroup",), "values": ("counter", 40, 90)}, {"service": self.p["svc"], "metric": "kafka_consumergroup_lag_sum", "labels": lab, "key": ("consumergroup",), "values": ("ints", 10, 300)}] def _kafka(self, rng, n, rates, lags): lab = self._kafka_labels() return [series("kafka_consumergroup_current_offset_sum", lab, counter_from_rates(rng, rates, rng.randint(10**6, 10**7))), series("kafka_consumergroup_lag_sum", lab, lags)] def spec(self, w, rng): s, n, groups = self.p["svc"], 80, [] def grp(name, rates, lags, fam): g = G(self.rid, name, n) g.series += background(w, rng, n) + self._kafka(rng, n, rates, lags) fam(g) g.labelless() groups.append(g.done()) base = rng.uniform(40, 90) st, en = rng.randint(28, 34), 60 rates = [0.0 if st <= m < en else base * rng.uniform(0.9, 1.1) for m in range(n + 1)] lags = [rng.randint(20, 200) if m < st else (int(base * 60 * (m - st)) if m < en else max(0, int(base * 60 * (en - st) - base * 90 * (m - en)))) for m in range(n + 1)] # the last offset increase lands in the sample at st - 1, so the group stopped right after it: the # runbook's 15 minutes run from there (`[6m]` pages at st + 14, `[7m]` one minute too late) grp("stall", rates, lags, lambda g: (g.fire(st + 14, s), g.quiet(0, st - 1, s))) st2, en2 = 15, 35 rates2 = [0.0 if st2 <= m < en2 else base * 1.6 for m in range(n + 1)] lags2 = [rng.randint(20, 200) if m < st2 else (int(base * 60 * (m - st2)) if m < en2 else max(5, int(base * 60 * 20 - base * 40 * (m - en2)))) for m in range(n + 1)] grp("recovered", rates2, lags2, lambda g: g.quiet(en2 + 10, n, s)) grp("idle_no_lag", [0.0] * (n + 1), [0] * (n + 1), lambda g: g.quiet(0, n, s)) # a rebalance holds commits for 4 minutes while lag builds (the runbook: that isn't a stall). A [4m] window # reads zero on two evaluations, so the rule's `for: 10m` (anything from 2m) stays quiet; no `for` pages. rb = 40 rates3 = [0.0 if rb <= m < rb + 4 else base * rng.uniform(0.9, 1.1) for m in range(n + 1)] lags3 = [int(base * 60 * (m - rb + 1)) if rb <= m < rb + 4 else rng.randint(20, 200) for m in range(n + 1)] grp("rebalance", rates3, lags3, lambda g: g.quiet(0, n, s)) grp("normal", [base * rng.uniform(0.9, 1.1) for _ in range(n + 1)], [rng.randint(10, 300) for _ in range(n + 1)], lambda g: g.quiet(0, n, s)) # the milder detect: a stall nobody fixes, checked half an hour in (a window too long for the runbook's 15 # minutes still pages by then; a rule that can't see a 1m-scraped counter never does) st4 = rng.randint(28, 34) rates4 = [0.0 if m >= st4 else base * rng.uniform(0.9, 1.1) for m in range(n + 1)] lags4 = [rng.randint(20, 200) if m < st4 else int(base * 60 * (m - st4)) for m in range(n + 1)] grp("long_stall", rates4, lags4, lambda g: g.fire(st4 + 29, s)) e = outcome_entry(self, w, {s: svc_class(w, s)}, named=self.ALERT) return e, groups def variants(self, w): v = lambda win, fn="rate": (lambda f, a: _set(f, self.ALERT, expr=self._expr(win, fn))) # noqa: E731 return [("oracle", lambda f, a: None, "accept"), ("window_2m", v("2m"), "accept"), ("window_6m", v("6m"), "accept"), ("window_10m", v("10m"), 0.5), ("window_7m", v("7m"), 0.5), ("irate_1m", v("1m", "irate"), 0.0), ("for_zero", drop_for(self.touch), 0.85), ("pristine", lambda f, a: self.break_(f, a, w), 0.0)] def ticket(self, w, rng): return prose.h09(self, w, rng) # ---------------------------------------------------------------------------- H10 class OrVectorZero(Item): code, kind, ticket_like = "H10", "outcome", True def setup(self, w, rng): cands = [s for s in w.services if s.kind == "consumer" and s.name not in w.notes.get("busy", set())] if not cands: return False s = rng.choice(cands) w.notes.setdefault("busy", set()).add(s.name) u = s.name.replace("-", "_") self.p.update(svc=s.name, metric=f"{u}_pending_batches", record=f"{u}:pending_batches:max", guard=f"{s.camel}MetricsMissing") home = home_group(w, s) home["rules"].insert(0, {"record": self.p["record"], "expr": f"max({self.p['metric']})"}) home["rules"].append({"alert": self.p["guard"], "expr": f"absent({self.p['record']})", "for": "10m", "labels": {"severity": "ticket", "team": s.team, "service": s.name}, "annotations": {"summary": f"no metrics from {s.name}", "runbook_url": w.runbook(self.p["guard"])}}) # scraped from the consumer's own target: it carries that target's labels (unify_targets pairs it with an `up`) w.notes.setdefault("background_series", []).append( {"service": s.name, "metric": self.p["metric"], "value": 3, "labels": {"job": s.name, "instance": f"{ip(rng)}:9102", "service": s.name, "namespace": w.namespace, "pod": pod_name(random.Random(s.name), s.name)}}) self.touch = {self.p["guard"], self.p["record"]} return True def break_(self, files, am, w): for _, _, r in rules_named(files, self.p["record"], "record"): r["expr"] = f"max({self.p['metric']}) or vector(0)" r["_comment"] = ["or vector(0) so the stat panel shows 0 instead of No data"] def spec(self, w, rng): s, n, groups = self.p["svc"], 60, [] m = self.p["metric"] def grp(name, vals, up, fam): g = G(self.rid, name, n) g.series += background(w, rng, n, {s}) inst = f"{ip(rng)}:9102" target = {"job": s, "instance": inst, "service": s, "namespace": w.namespace, "pod": pod_name(rng, s)} g.series += [series(m, target, vals), series("up", target, up)] fam(g) g.labelless() groups.append(g.done()) wig = [rng.randint(2, 6) for _ in range(n + 1)] van = wig[:20] + ["stale"] + [None] * (n - 20) # The pods stay up and only the batch metric goes away: a target that vanishes is the Down alert's job # (it has `or absent(up{...})`), so the survey story only holds while `up` is still there. grp("vanish", van, [1] * (n + 1), lambda g: (g.fire(50, s, cls="ticket"), g.quiet(0, 19, s, cls="ticket"))) def healthy(g): g.quiet(0, n, s, cls="ticket") g.count(f"count(abs({self.p['record']} - {wig[40]}) < 0.001) or vector(0)", 40, 1, "F_regress") grp("healthy", wig, [1] * (n + 1), healthy) grp("idle", [0] * (n + 1), [1] * (n + 1), lambda g: g.quiet(0, n, s, cls="ticket")) # the gauge drops out for two minutes while the consumer reconnects (the survey says that's normal): an # absent() guard is true on two evaluations, so any `for` from 2m stays quiet blink = wig[:20] + ["stale", None] + wig[22:] grp("reconnect", blink, [1] * (n + 1), lambda g: g.quiet(0, n, s, cls="ticket")) # the milder detect: the consumer scaled to zero, its target gone from discovery with the metric (a guard on # the target's own `up` sees this one, not the metric going away under a live target) grp("scaled_to_zero", van, [1] * 20 + ["stale"] + [None] * (n - 20), lambda g: g.fire(50, s, cls="ticket")) e = outcome_entry(self, w, {s: svc_class(w, s, "ticket")}) e["outcome"]["classes"] = {"ticket": svc_class(w, s, "ticket")} return e, groups def variants(self, w): s = self.p["svc"] g, m = self.p["guard"], self.p["metric"] def guard(expr, for_="10m", keep_fallback=True): def f(files, am): if keep_fallback: self.break_(files, am, w) _set(files, g, expr=expr, **{"for": for_}) return f return [("oracle", lambda f, a: None, "accept"), ("guard_on_raw_metric", guard(f"absent({m})"), "accept"), ("guard_on_raw_metric_service", guard(f'absent({m}{{service="{s}"}})'), "accept"), ("guard_on_raw_metric_for_2m", guard(f"absent({m})", "2m"), "accept"), ("guard_on_raw_metric_for_1m", guard(f"absent({m})", "1m"), 0.8), ("for_zero", drop_for([g]), 0.8), ("guard_on_up", guard(f'absent(up{{job="{s}"}} == 1)'), 0.5), ("absent_over_time_10m", guard(f"absent_over_time({m}[10m])"), "accept"), ("guard_up_eq_0", guard(f'up{{job="{s}"}} == 0'), 0.0), ("absent_over_time_30m", guard(f"absent_over_time({m}[30m])"), 0.0), ("pristine", lambda f, a: self.break_(f, a, w), 0.0)] def ticket(self, w, rng): return prose.h10(self, w, rng) # ---------------------------------------------------------------------------- H23 class DiskPredict(Item): code, kind, ticket_like = "H23", "outcome", True ALERT = "DiskWillFillIn4h" def setup(self, w, rng): cands = [s for s in w.services if s.kind in ("api", "consumer", "worker") and s.home.startswith("legacy-") and s.name not in w.notes.get("busy", set())] if not cands: return False s = rng.choice(cands) w.notes.setdefault("busy", set()).add(s.name) self.p.update(svc=s.name, page=f"{s.camel}DiskAlmostFull", size=200 * 10**9) sel = f'{{service="{s.name}",mountpoint="/var/lib/postgresql"}}' self.p["sel"] = sel grp = home_group(w, s) grp["rules"] += [ {"alert": self.ALERT, "expr": f"predict_linear(node_filesystem_avail_bytes{sel}[1h], 4 * 3600) < 0 and node_filesystem_avail_bytes{sel} / node_filesystem_size_bytes{sel} < 0.15", "for": "30m", "labels": {"severity": "ticket", "team": s.team}, "annotations": {"summary": "{{ $labels.service }} database volume will fill within 4 hours", "runbook_url": w.runbook(self.ALERT)}}, {"alert": self.p["page"], "expr": f"node_filesystem_avail_bytes{sel} / node_filesystem_size_bytes{sel} < 0.05", "for": "5m", "labels": {"severity": "page", "team": s.team}, "annotations": {"summary": "{{ $labels.service }} database volume is under 5% free", "runbook_url": w.runbook(self.p["page"])}}] self.touch = {self.ALERT, self.p["page"]} self.names = {self.ALERT} return True def exporters(self, w): # the database volume sits at a steady 58% free in every scenario that isn't about it s, size = self.p["svc"], self.p["size"] lab = {"service": s, "mountpoint": "/var/lib/postgresql", "device": "/dev/nvme1n1", "fstype": "ext4", "instance": f"{ip(random.Random(f'node-exporter:{s}'))}:9100", "job": "node"} return [{"service": s, "metric": m, "labels": lab, "key": ("service", "mountpoint"), "values": ("const", v)} for m, v in (("node_filesystem_avail_bytes", int(size * 0.58)), ("node_filesystem_size_bytes", size))] def break_(self, files, am, w): sel = self.p["sel"] _set(files, self.ALERT, expr=f"predict_linear(node_filesystem_avail_bytes{sel}[1h], 4 * 3600) < 0") for _, _, r in rules_named(files, self.ALERT): r["labels"]["severity"] = "page" r.pop("for", None) r["for"] = "5m" from .model import drop_rules drop_rules(files, {self.p["page"]}) def spec(self, w, rng): s, size, groups = self.p["svc"], self.p["size"], [] def grp(name, avail, fam): n = len(avail) - 1 g = G(self.rid, name, n) lab = {"service": s, "mountpoint": "/var/lib/postgresql", "device": "/dev/nvme1n1", "fstype": "ext4", "instance": f"{ip(rng)}:9100", "job": "node"} g.series += background(w, rng, n) + [series("node_filesystem_avail_bytes", lab, [int(x) for x in avail]), series("node_filesystem_size_bytes", lab, [size] * (n + 1))] fam(g) g.labelless() groups.append(g.done()) gb = 10**9 slow = [60 * gb - 0.1 * gb * m for m in range(521)] grp("slow_fill", slow, lambda g: (g.quiet(0, 340, s, cls="ticket"), g.fire(500, s, cls="ticket"), g.quiet(0, 500, s, "S_defect", cls="page"), g.fire(510, s, cls="page"))) # nightly backup at 50% free: ~55 GB written in 45 minutes (a 4h linear prediction goes below zero), # deleted an hour later; the level never gets near 15% free wr = rng.randint(52, 58) backup = [100 * gb - (wr * gb * (m - 120) / 45 if 120 <= m < 165 else wr * gb if 165 <= m < 225 else 0) for m in range(301)] grp("backup_sawtooth", backup, lambda g: (g.quiet(0, 300, s, cls="ticket"), g.quiet(0, 300, s, "S_defect", cls="page"))) flood = [60 * gb if m < 120 else max(1 * gb, 60 * gb - 0.6 * gb * (m - 120)) for m in range(216)] cross = next(m for m, v in enumerate(flood) if v / size < 0.05) grp("log_flood", flood, lambda g: (g.fire(cross + 10, s, "F_regress", cls="page"), g.quiet(0, 119, s, cls="page"))) # a volume sitting at 8% free dips under 5% for two minutes (a compaction's scratch files): ADR 0012 pages # at "under 5% free for 5 minutes", so the page's `for` (anything from 2m) stays quiet; no `for` pages dip = [int(size * (0.03 if 90 <= m < 92 else 0.08)) for m in range(151)] grp("short_dip", dip, lambda g: g.quiet(0, 150, s, cls="page")) e = outcome_entry(self, w, {s: svc_class(w, s, "ticket")}) e["outcome"]["classes"] = {"ticket": svc_class(w, s, "ticket"), "page": svc_class(w, s, "page")} e["outcome"]["expected_count"] = 2 return e, groups def variants(self, w): sel = self.p["sel"] pl = lambda win: f"predict_linear(node_filesystem_avail_bytes{sel}[{win}], 4 * 3600) < 0" # noqa: E731 lvl = f"node_filesystem_avail_bytes{sel} / node_filesystem_size_bytes{sel} < 0.15" def ticket(win, for_): return lambda f, a: _set(f, self.ALERT, expr=f"{pl(win)} and {lvl}", **{"for": for_}) def pred_only_6h(files, am): self.break_(files, am, w) _set(files, self.ALERT, expr=pl("6h")) def keep_page(files, am): for _, _, r in rules_named(files, self.ALERT): r["labels"]["severity"] = "page" return [("oracle", lambda f, a: None, "accept"), ("mixin_6h_for_1h", ticket("6h", "1h"), "accept"), ("ticket_for_2h", ticket("1h", "2h"), "accept"), ("ticket_for_150m", ticket("1h", "150m"), 0.5), ("guarded_prediction_still_pages", keep_page, 0.3), ("six_hour_window_only", pred_only_6h, 0.0), ("page_for_zero", drop_for([self.p["page"]]), 0.8), ("pristine", lambda f, a: self.break_(f, a, w), 0.0)] def ticket(self, w, rng): return prose.h23(self, w, rng)