配置Mappings
Creating new mappings can be done using the put_mapping API. When a document is indexed with no mapping associated with it in the specific index, the dynamic / default mapping feature will kick in an automatically create mapping definition for it.
我们可以使用 put_mapping API 创建自己的mapping type.在建立索引时，ES默认使用动态mapping配置.
Mappings can also be provided on the node level, meaning that each index created will automatically be started with all the mappings defined within a certain location.
Mapping也可以在节点上配置，就是说 ES自动地使用指定位置的定义好了的所有mappings开始建索引.
Mappings can be defined within files called [mapping_name].json and be placed either under config/mappings/_default location, or under config/mappings/[index_name] (for mappings that should be associated only with a specific index).
Mappings 以 [mapping_name].json 形式存在，文件存放在 config/mappings/_default 或 config/mappings/[index_name] (针对特定的index).
