LLM Function Invocation Metrics Report

This report covers the metrics available on the LLM function invocation path: the LLM API Gateway, the LLM Request Router, and the Stargate client sidecar in LLM function pods.

Scrape points

Component	Endpoint	Service name	Metric prefix
LLM API Gateway	`llm-api-gateway:9464/metrics`	`llm-api-gateway`	`llm_api_gateway_`
Rate limit sync worker	`:9464/metrics` when deployed with `METRICS_PORT=9464`	`llm-api-gateway-rate-limit-sync-worker`	`llm_api_gateway_`
LLM Request Router	`llm-request-router:9090/metrics`	`stargate`	`stargate_`
Stargate client sidecar	`:9089/metrics` by default	`stargate-client`	`stargate_client_`

The request-router chart passes --metrics-port and uses Stargate’s default metric prefix and trace service name.

LLM API Gateway

Metric	Labels
`llm_api_gateway_http_requests_total`	`method`, `route`, `status`
`llm_api_gateway_http_request_duration_seconds`	`method`, `route`, `status`
`llm_api_gateway_http_active_requests`	`method`, `route`
`llm_api_gateway_upstream_requests_total`	`upstream`, `result`, `status`
`llm_api_gateway_upstream_request_duration_seconds`	`upstream`, `result`, `status`
`llm_api_gateway_llm_tokens_total`	`endpoint`, `token_type`, `stream`
`llm_api_gateway_provider_time_seconds`	`endpoint`, `phase`, `stream`
`llm_api_gateway_stream_first_token_seconds`	`endpoint`
`llm_api_gateway_stream_duration_seconds`	`endpoint`, `status`
`llm_api_gateway_pubsub_publish_failures_total`	None
`llm_api_gateway_pubsub_consume_failures_total`	None
`llm_api_gateway_pubsub_consume_duration_seconds`	None
`llm_api_gateway_rate_limit_event_replication_lag_seconds`	None
`llm_api_gateway_rate_limit_events_received_total`	None
`llm_api_gateway_rate_limit_events_dropped_total`	`reason`
`llm_api_gateway_rate_limit_events_applied_total`	None
`llm_api_gateway_rate_limit_events_failed_apply_total`	None
`llm_api_gateway_rate_limit_events_dry_run_would_apply_total`	None
`llm_api_gateway_rate_limit_synchronizer_publish_duration_seconds`	None
`llm_api_gateway_rate_limit_synchronizer_queue_wait_seconds`	None
`llm_api_gateway_rate_limit_synchronizer_queue_length`	None
`llm_api_gateway_rate_limit_synchronizer_events_dropped_total`	`reason`

The sync worker reuses the same telemetry package and emits the rate limit synchronizer and Pub/Sub metrics under the worker service name.

LLM Request Router

Metric	Labels
`stargate_requests_total`	`routing_key`, `model`, `inference_server_id`, `status`
`stargate_proxy_attempts_total`	`routing_key`, `model`, `inference_server_id`, `result`
`stargate_proxy_retries_total`	`routing_key`, `model`, `reason`
`stargate_routing_selections_total`	`routing_key`, `model`, `algorithm`, `selection`
`stargate_routing_kv_free_token_fallback_selections_total`	`routing_key`, `model`, `algorithm`
`stargate_proxy_retry_exhausted_total`	`routing_key`, `model`, `reason`
`stargate_admission_rejections_total`	`routing_key`, `model`, `reason`
`stargate_quic_connection_evictions_total`	`inference_server_id`, `reason`
`stargate_quic_hot_path_reconnect_total`	`inference_server_id`, `result`
`stargate_proxy_replay_buffer_bytes`	`model`
`stargate_proxy_duration_seconds`	`routing_key`, `model`, `inference_server_id`
`stargate_routing_duration_seconds`	`routing_key`, `model`
`stargate_active_inference_servers`	`routing_key`, `model`

Stargate Client Sidecar

Metric	Labels
`target_info`	`service_version`, `service_name`, `commit`
`stargate_client_requests_inflight`	`model`
`stargate_client_requests_state`	`model`, `state`
`stargate_client_requests_state_input_tokens`	`model`, `state`
`stargate_client_requests_total`	`model`, `routing_key`, `status`
`stargate_client_request_time_to_response_headers_seconds`	`model`, `routing_key`
`stargate_client_request_time_to_first_output_seconds`	`model`, `routing_key`
`stargate_client_request_time_to_first_token_seconds`	`model`, `routing_key`
`stargate_client_request_duration_seconds`	`model`, `routing_key`, `status`
`stargate_client_request_input_tokens_total`	`model`, `routing_key`, `status`
`stargate_client_request_output_tokens_total`	`model`, `routing_key`, `status`
`stargate_client_request_input_tokens`	`model`, `routing_key`, `status`
`stargate_client_request_output_tokens`	`model`, `routing_key`, `status`
`stargate_client_registration_stream_connected`	`router`
`stargate_client_reverse_tunnel_connected`	`router`
`stargate_client_model_input_tps`	`model`
`stargate_client_model_output_tps`	`model`
`stargate_client_model_max_input_tps`	`model`
`stargate_client_model_max_output_tps`	`model`
`stargate_client_model_queue_size`	`model`
`stargate_client_model_queued_input_tokens`	`model`
`stargate_client_model_kv_cache_capacity_tokens`	`model`
`stargate_client_model_kv_cache_used_tokens`	`model`
`stargate_client_model_kv_cache_free_tokens`	`model`
`stargate_client_model_advertised_status`	`router`, `model`, `status`
`stargate_client_retryable_responses_total`	`inference_server_id`, `reason`, `status`
`stargate_client_nonretryable_failures_total`	`inference_server_id`, `reason`

Keep request IDs, session IDs, function IDs, organization IDs, project IDs, authorization values, raw prompts, and raw URLs out of metric labels.