Files
张宗平 031aa35604 fix(schema): escape TDengine 3.4 reserved words 'value'/'label' and use column alias for ANOMALY_WINDOW
- schema: rename label -> is_anomaly, escape `value` as backtick
- detection/forecast: wrap subquery with SELECT ts, `value` AS v
  so ANOMALY_WINDOW/FORECAST receive non-keyword column name
- resolves [0x2600] syntax error and unblocks E2E pipeline on community tsdb 3.4.1
2026-06-11 16:08:34 +08:00

109 lines
2.9 KiB
Python

"""预测式异常模块:FORECAST + 区间外点判定。"""
import logging
from typing import TypedDict
logger = logging.getLogger(__name__)
class ForecastPoint(TypedDict):
ts: int
value: float
_flow: float
_fhigh: float
is_anomaly: bool
def run_forecast(
conn,
stable: str,
algo: str = "holtwinters",
rows: int = 10,
conf: int = 95,
) -> list[tuple[int, float, float]]:
"""执行 FORECAST 查询。
Args:
conn: TDConnection 实例
stable: supertable 名称
algo: 预测算法,默认 holtwinters
rows: 预测行数
conf: 置信度百分比
Returns:
[(frowts_ms, flow, fhigh), ...]
Raises:
RuntimeError: SQL 执行失败
"""
sql = (
f"SELECT _FROWTS, _FLOW, _FHIGH "
f"FROM (SELECT ts, `value` AS v FROM ds_{stable}) "
f"FORECAST(v, 'algo={algo},rows={rows},conf={conf}')"
)
try:
raw = conn.execute(sql)
except Exception as e:
raise RuntimeError(f"FORECAST 执行失败: {e}") from e
results = []
for row in raw:
frowts = int(row[0]) if row[0] is not None else 0
flow = float(row[1]) if row[1] is not None else 0.0
fhigh = float(row[2]) if row[2] is not None else 0.0
results.append((frowts, flow, fhigh))
return results
def forecast_anomaly(
conn, stable: str, algo: str = "holtwinters", rows: int = 10, conf: int = 95
) -> list[ForecastPoint]:
"""FORECAST 预测并判定区间外异常。
步骤:
1. 执行 FORECAST,获取 [(_flow, _fhigh)] 区间
2. 查询预测区间对应的原始数据
3. 比较判定:value < _flow or value > _fhigh → is_anomaly
Args:
conn: TDConnection 实例
stable: supertable 名称
algo: 预测算法
rows: 预测行数
conf: 置信度百分比
Returns:
ForecastPoint 列表(含 is_anomaly 标记)
"""
forecasts = run_forecast(conn, stable, algo, rows, conf)
if not forecasts:
return []
frowtses = [f[0] for f in forecasts]
start_ts = min(frowtses)
end_ts = max(frowtses)
sql = f"SELECT ts, `value` FROM s_{stable} WHERE ts >= {start_ts} AND ts <= {end_ts}"
raw = conn.execute(sql)
fmap = {f[0]: (f[1], f[2]) for f in forecasts}
results: list[ForecastPoint] = []
for row in raw:
ts = int(row[0])
value = float(row[1])
if ts in fmap:
flow, fhigh = fmap[ts]
is_anom = value < flow or value > fhigh
else:
flow, fhigh = 0.0, 0.0
is_anom = False
results.append(ForecastPoint(
ts=ts, value=value, _flow=flow, _fhigh=fhigh, is_anomaly=is_anom
))
logger.info(
"forecast_anomaly: %d points, %d anomalies",
len(results), sum(1 for r in results if r["is_anomaly"]),
)
return results