New Relic 401s come from using a license key where a user key belongs

Create two separate keys: an ingest license key for shipping data and a user key for queries, and label them so they never get swapped. Match the API region to your login URL, EU accounts use the EU hostname. When an NRQL query times out, add a SINCE bound and a WHERE filter on service or host before assuming the data is missing.

Context: A New Relic integration troubleshooting guide documents the three setup mistakes that produce the most confusion. First, a 401 on the connection query usually means an ingest license key was used where a user API key is required: the license key ships data to New Relic, while only a user key can run NerdGraph queries. Second, accounts in the EU region fail with account-not-found errors when the region is set to US, because the API hostname differs. Third, NRQL queries that time out need a narrower time window or filters on specific attributes to cut the scanned data volume.