在配置es外部表的时候，建表完成之后，查询时报错：
mysql> select * from common_asset_info_Es;
ERROR 1064 (HY000): fetch es table [common_asset_info_Es] metadata failure: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
是否是需要配置ca，怎么配置呢