VirtualService Route Misconfiguration Blackhole
criticalIncorrectly configured VirtualService routing rules cause traffic to be silently dropped or routed to wrong destinations. Common issues include case-sensitive mismatches, missing DestinationRules, or conflicting route priorities.
Run istioctl analyze to detect configuration errors like IST0101 (referenced resource not found) or IST0103 (port name convention violations). Monitor istio_pilot_xds_rds_reject for rejected route configurations. Check istio_pilot_invalid_out_listeners for invalid listener configurations. Look for istio_pilot_duplicate_envoy_clusters indicating configuration conflicts.
Use istioctl analyze before applying configuration changes. Verify VirtualService host names exactly match Service names (case-sensitive). Ensure DestinationRules exist for all VirtualService destinations. Check that port names follow Istio conventions (protocol-suffix format). Use istioctl proxy-config routes to verify routing rules are correctly applied to sidecars.