I'm looking at a test ElasticSearch instance @ 6.7.1 upgrade to 7.0. The upgrade assistant says that the metricbeat templates for the cluster need looking at. Basically it says:-
"Index templates [metricbeat-7.0.0, metricbeat-6.6.1, metricbeat-6.6.2] have a number of fields which exceeds the automatic field expansion limit of  and does not have [index.query.default_field] set, which may cause queries which use automatic field expansion, such as query_string, simple_query_string, and multi_match to fail if fields are not explicitly specified in the query."
Any ideas how I might resolve this issue before upgrading?