No data threshold #370 (#396)

"No data" threshold support

analytics/analytics/detectors/threshold_detector.py

@@ -6,6 +6,7 @@ from typing import Optional
 from detectors import Detector
 from models import ModelCache
 from time import time
+from utils import convert_sec_to_ms
 
 
 logger = log.getLogger('THRESHOLD_DETECTOR')
@@ -28,15 +29,25 @@ class ThresholdDetector(Detector):
         value = cache['value']
         condition = cache['condition']
 
+        now = convert_sec_to_ms(time())
+        segment = ({'from': now, 'to': now})
+        segments = []
+
         dataframe_without_nans = dataframe.dropna()
         if len(dataframe_without_nans) == 0:
-            return dict()
+            if condition == 'NO_DATA':
+                segments.append(segment)
+                return {
+                    'cache': cache,
+                    'segments': segments,
+                    'lastDetectionTime': now
+                }
+            else:
+                return None
+
         last_entry = dataframe_without_nans.iloc[-1]
         last_value = last_entry['value']
 
-        now = int(time()) * 1000
-        segment = ({ 'from': now, 'to': now })
-        segments = []
         if condition == '>':
             if last_value > value:
                 segments.append(segment)

analytics/analytics/utils/common.py

@@ -22,12 +22,6 @@ def exponential_smoothing(series, alpha):
         result.append(alpha * series[n] + (1 - alpha) * result[n - 1])
     return result
 
-def anomalies_to_timestamp(anomalies):
-    for anomaly in anomalies:
-        anomaly['from'] = int(anomaly['from'].timestamp() * 1000)
-        anomaly['to'] = int(anomaly['to'].timestamp() * 1000)
-    return anomalies
-
 def segments_box(segments):
     max_time = 0
     min_time = float("inf")
@@ -326,3 +320,6 @@ def cut_dataframe(data: pd.DataFrame) -> pd.DataFrame:
 
 def get_min_max(array, default):
     return float(min(array, default=default)), float(max(array, default=default))
+
+def convert_sec_to_ms(sec):
+    return int(sec) * 1000

server/src/models/threshold_model.ts

@@ -12,7 +12,8 @@ export enum Condition {
   ABOVE_OR_EQUAL = '>=',
   EQUAL = '=',
   LESS_OR_EQUAL = '<=',
-  LESS = '<'
+  LESS = '<',
+  NO_DATA = 'NO_DATA'
 };
 
 export class Threshold {