Meanwhile Phabricator reconfigured their infrastructure to use raw IP addresses just to avoid node DNS issues, before eventually implementing an in-memory cacheopens in a new tab, and Yahoo implementedopens in a new tab their own DNS caching module to try and improve node's DNS performance. It supports caching, which observes the DNS TTL plus a configurable maximum cache time, it supports configurable error caching too, it supports custom DNS servers, it (optionally) supports fallback to dns.lookup for domains that can't be resolved via real DNS like localhost et al, it's all asynchronous, and it's super easy to use. If you'd like to add DNS servers, rather than replacing the default DNS configuration (i.e.