Elastic search not picking up changes for updated conf files

I had created an index in elastic search,now when i tried to update/change the conf files i.e. I changed the index name but I cannot see a new index being created.Does the elastic search picks up the changes in conf files automatically or we have to manually trigger it.

Logstash will notice changes to the configuration and reload the pipelines if you have --config.reload.automatic on the command line.