Elasticsearch log level settings

Hi

There are lot of configurations in log4j properties. I'm using logstash to insert records to elasticsearch and I need to log those. Where should I enable log in elasticsearch? what is logging hierarchy in this case?
what is the effect of changing below config?

logger.action.name = org.elasticsearch.action
logger.action.level = debug

With above debug setting, I dont see any indication neither in elasticsearch.log or elasticsearch-server.log, when records getting inserted through logstash output plugin

Regards
Ram