diff --git a/shared/middleware/net_sim_api.rb b/shared/middleware/net_sim_api.rb
index 09bd14bc6b788..89dbfb8cd0d7f 100644
--- a/shared/middleware/net_sim_api.rb
+++ b/shared/middleware/net_sim_api.rb
@@ -225,7 +225,7 @@ def owns_shard?(shard_id)
 
     # Block request if payload is unusually large.
     if body_string.length > MAX_REQUEST_SIZE
-      record_metric("InsertTooLarge_#{table_name}", body_string.length)
+      record_metric("InsertTooLarge_#{table_name}", body_string.length, 'Bytes')
       too_large
     end
 
@@ -251,7 +251,7 @@ def owns_shard?(shard_id)
     table = get_table(shard_id, table_name)
     result = values.map {|value| table.insert(value, request.ip)}
 
-    record_metric("InsertBytes_#{table_name}", body_string.length)
+    record_metric("InsertBytes_#{table_name}", body_string.length, 'Bytes')
     record_metric("InsertRows_#{table_name}", values.count)
 
     # Finally, if we are not performing a multi-insert, denormalize our
@@ -355,7 +355,7 @@ def validate_wire(shard_id, wire)
 
     # Block request if payload is unusually large.
     if body_string.length > MAX_REQUEST_SIZE
-      record_metric("UpdateTooLarge_#{table_name}", body_string.length)
+      record_metric("UpdateTooLarge_#{table_name}", body_string.length, 'Bytes')
       too_large
     end
 
@@ -369,7 +369,7 @@ def validate_wire(shard_id, wire)
       json_bad_request
     end
 
-    record_metric("UpdateBytes_#{table_name}", body_string.length)
+    record_metric("UpdateBytes_#{table_name}", body_string.length, 'Bytes')
 
     dont_cache
     content_type :json
@@ -504,7 +504,9 @@ def delete_messages_for_nodes(shard_id, node_ids)
   # @param [String] event_type - unique metric key within NetSimApi
   # @param [Number] value (default 1) value of measurement, omit if we only care
   #   about event counts.
-  def record_metric(event_type, value = 1)
+  # @param [String] unit (default 'Count') unit of measurement. For allowed units,
+  #   see https://docs.aws.amazon.com/sdkforruby/api/Aws/CloudWatch/Types/MetricDatum.html#unit-instance_method
+  def record_metric(event_type, value = 1, unit = 'Count')
     return unless CDO.netsim_enable_metrics
     Cdo::Metrics.push('NetSimApi',
       [