While investigating something else I discovered that puppetdb hosts are exporting a ton of metrics, with the hostname in the metric name. Prometheus isn't happy about that and we are already blacklisting some mbeans, likely the blacklist needs to be expanded.
puppetdb1001:~$ curl -s 10.64.32.214:9400/metrics | grep ^puppetlabs_puppetdb_http_pdb_query_v4_catalogs | wc -l 57060 puppetdb1001:~$ curl -s 10.64.32.214:9400/metrics | grep ^puppetlabs_puppetdb_http_pdb_query_v4_catalogs | head -2 puppetlabs_puppetdb_http_pdb_query_v4_catalogs_mw2231_codfw_wmnet_resources_service_time_98thPercentile 480.154882 puppetlabs_puppetdb_http_pdb_query_v4_catalogs_wdqs1010_eqiad_wmnet_service_time_50thPercentile 300.70412999999996