FQDN Active Names Memory Pressure
warningHigh cilium_fqdn_active_names or cilium_fqdn_active_ips counts indicate DNS-based policy consuming significant memory. When combined with low cilium_fqdn_gc_deletions_datadog, stale entries accumulate, causing endpoint regeneration delays and potential OOM conditions.
Monitor cilium_fqdn_active_names and cilium_fqdn_active_ips growth. If counts grow unbounded while cilium_fqdn_gc_deletions_datadog remains low, GC is not keeping pace with DNS churn. Cross-reference with cilium_process_resident_memory_size to detect memory pressure.
Tune DNS garbage collection intervals. Review FQDN policies to ensure they target specific domains rather than wildcards. Monitor cilium_fqdn_alive_zombie_backend for leaked references. Consider reducing DNS TTL caching duration for frequently changing external services. Increase agent memory limits if necessary.