Elastic search data source - getting a 503

I have installed Grafana using the tar ball and started it. Didnt do any other configuration changes.

When I go to adding an elasticsearch datasource. i get the below error

in the grafana logs i see

t=2020-12-03T14:43:47-0500 lvl=eror msg=“Request Completed” logger=context userId=1 orgId=1 uname=admin method=GET path=/api/datasources/proxy/2/mtest_myindex/_mapping status=503 remote_addr=****** time_ms=75097 size=4832 referer=http://:3000/datasources/edit/2/

i can run a curl from the servername to my elastic search url and get the mapping back fine.

not sure why i am getting a 503.