/** The key of the configuration. e.g. 100 */
    String INDEX_REINDEX_SIZE = "index.reindex.size";

    /** The key of the configuration. e.g. {"source":{"index":"__SOURCE_INDEX__","size":__SIZE__},"dest":{"index":"__DEST_INDEX__"},"script":{"source":"__SCRIPT_SOURCE__"}} */
    String INDEX_REINDEX_BODY = "index.reindex.body";

    /** The key of the configuration. e.g. adaptive */