Analytics: Aggregator now throw an exception when computing fails

analytics/analyzers/aggregator/AggregatorAnalyzer.cpp

@@ -50,10 +50,8 @@ void AggregatorAnalyzer::compute(U_Ptr unit) {
         // Since we do not clear the internal buffer, all sensor readings will be accumulated in the same vector
         elCtr = _buffer==nullptr ? 0 : _buffer->size();
         _buffer = _queryEngine.querySensor(in->getName(), _window, 0, _buffer);
-        if(!_buffer || _buffer->size()<=elCtr) {
-            LOG(debug) << "Analyzer " << _name << " cannot read from sensor " << in->getName() << "!";
-            return;
-        }
+        if(!_buffer || _buffer->size()<=elCtr)
+            throw std::runtime_error("Analyzer " + _name + ": cannot read from sensor " + in->getName() + "!");
     }
     compute_internal(unit, _buffer);
 }