collecting index stats metrics failed with 400 status code error

[bydeath]

It failed to collect index stats metrics, log of elasticsearch_exporter says

level=warn ts=2021-06-24T03:28:03.553975379Z caller=indices.go:1094 msg="failed to fetch and decode index stats" err="HTTP Request failed with code 400"

It returns an index_closed_exception 400 response below when I access _all/_stats of the elasticsearch cluster.

{"error":{"root_cause":[{"type":"index_closed_exception","reason":"closed","index_uuid":"TYsMR-7CQcu5a87Olryvwg","index":"test"}],"type":"index_closed_exception","reason":"closed","index_uuid":"TYsMR-7CQcu5a87Olryvwg","index":"test"},"status":400}

Response steps:

1. Enable security of elasticsearch cluster, and http basic auth is required to access the cluster.
2. PUT test
3. PUT test/_alias/test_alias
4. POST test/_close
5. GET _all/_stats
6. start elasticsearch_exporter and curl localhost:9114/metrics.

[bydeath]

underlying issue elastic/elasticsearch/issues/74540