Add comment why it is safe to check the number of nested fields in Ma…

…pperService.merge.
elastic · Mar 29, 2016 · c7bdfb1 · c7bdfb1
1 parent 0eedc78
commit c7bdfb1
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/core/src/main/java/org/elasticsearch/index/mapper/MapperService.java b/core/src/main/java/org/elasticsearch/index/mapper/MapperService.java
@@ -283,6 +283,11 @@ private synchronized DocumentMapper merge(DocumentMapper mapper, MergeReason rea
         fullPathObjectMappers = Collections.unmodifiableMap(fullPathObjectMappers);
 
         if (reason == MergeReason.MAPPING_UPDATE) {
+            // this check will only be performed on the master node when there is
+            // a call to the update mapping API. For all other cases like
+            // the master node restoring mappings from disk or data nodes
+            // deserializing cluster state that was sent by the master node,
+            // this check will be skipped.
             checkNestedFieldsLimit(fullPathObjectMappers);
         }