Revert of Add field_specs to all metrics in luci-py

client/third_party/infra_libs/ts_mon/common/interface.py

Index: client/third_party/infra_libs/ts_mon/common/interface.py
diff --git a/client/third_party/infra_libs/ts_mon/common/interface.py b/client/third_party/infra_libs/ts_mon/common/interface.py
index 8091490fc7ed161910e41a890c2fc37d151e6b89..6f10c408deeb1bb0a93f9000fb5af16b68deb431 100644
--- a/client/third_party/infra_libs/ts_mon/common/interface.py
+++ b/client/third_party/infra_libs/ts_mon/common/interface.py
@@ -123,6 +123,7 @@
   data_sets = {}
 
   count = 0
+  error_count = 0
   for (target, metric, start_time, end_time, fields_values
        ) in state.store.get_all():
     for fields, value in fields_values.iteritems():
@@ -140,12 +141,17 @@
 
       key = (target, metric.name)
       new_data_set = None
-      if key not in data_sets:
-        new_data_set = new_metrics_pb2.MetricsDataSet()
-        metric._populate_data_set(new_data_set)
-
-      data = new_metrics_pb2.MetricsData()
-      metric._populate_data(data, start_time, end_time, fields, value)
+      try:
+        if key not in data_sets:
+            new_data_set = new_metrics_pb2.MetricsDataSet()
+            metric._populate_data_set(new_data_set, fields)
+
+        data = new_metrics_pb2.MetricsData()
+        metric._populate_data(data, start_time, end_time, fields, value)
+      except errors.MonitoringError:
+        logging.exception('Failed to serialize a metric.')
+        error_count += 1
+        continue
 
       # All required data protos have been successfully populated. Now we can
       # insert them in serialized proto and bookeeping data structures.
@@ -158,24 +164,36 @@
   if count > 0:
     yield proto
 
+  if error_count:
+    raise errors.MonitoringFailedToFlushAllMetricsError(error_count)
+
 
 def _generate_proto():
   """Generate MetricsCollection for global_monitor.send()."""
   proto = metrics_pb2.MetricsCollection()
 
+  error_count = 0
   for target, metric, start_time, _, fields_values in state.store.get_all():
     for fields, value in fields_values.iteritems():
       if len(proto.data) >= METRICS_DATA_LENGTH_LIMIT:
         yield proto
         proto = metrics_pb2.MetricsCollection()
 
-      metrics_pb = metrics_pb2.MetricsData()
-      metric.serialize_to(metrics_pb, start_time, fields, value, target)
+      try:
+        metrics_pb = metrics_pb2.MetricsData()
+        metric.serialize_to(metrics_pb, start_time, fields, value, target)
+      except errors.MonitoringError:
+        error_count += 1
+        logging.exception('Failed to serialize a metric.')
+        continue
 
       proto.data.add().CopyFrom(metrics_pb)
 
   if len(proto.data) > 0:
     yield proto
+
+  if error_count:
+    raise errors.MonitoringFailedToFlushAllMetricsError(error_count)
 
 
 def register(metric):