Error: didn't return 200 OK but 422 Unprocessable Entity while running for large number of metrics

[Sarang-Sangram]

Its throwing error if I try to export metrics which are more then 400 thousands. :

2020/05/06 00:38:50 didn't return 200 OK but 422 Unprocessable Entity: http://host.prom.com:32322/api/v1/query_range?end=1588739921&query=systemcalls%7Bevtnum+%21%3D+%227000%22%7D&start=1588736321&step=14
0

[metalmatze]

Interesting. Happy to accept PRs trying to fix this.