Use Dataset API

The get_pings API has been deprecated

mozaggregator/aggregator.py

@@ -7,7 +7,7 @@
 
 import sys
 
-from moztelemetry.spark import get_pings
+from moztelemetry.dataset import Dataset 
 from moztelemetry.histogram import cached_exponential_buckets
 from collections import defaultdict
 
@@ -28,8 +28,12 @@ def aggregate_metrics(sc, channels, submission_date, fraction=1):
         channels = [channels]
 
     channels = set(channels)
-    rdds = [get_pings(sc, channel=ch, submission_date=submission_date, doc_type="saved_session", schema="v4", fraction=fraction) for ch in channels]
-    pings = reduce(lambda x, y: x.union(y), rdds)
+    pings = Dataset.from_source('telemetry') \
+                  .where(appUpdateChannel=lambda x : x in channels, 
+                         submissionDate=submission_date,
+                         docType="saved_session",
+                         sourceVersion='4') \
+                  .records(sc, sample=fraction)
     return _aggregate_metrics(pings)