Statistics

Every connection manager has a statistics tree rooted at http.<stat_prefix>. with the following statistics:

Name Type Description
downstream_cx_total Counter Total connections
downstream_cx_ssl_total Counter Total TLS connections
downstream_cx_http1_total Counter Total HTTP/1.1 connections
downstream_cx_websocket_total Counter Total WebSocket connections
downstream_cx_http2_total Counter Total HTTP/2 connections
downstream_cx_destroy Counter Total connections destroyed
downstream_cx_destroy_remote Counter Total connections destroyed due to remote close
downstream_cx_destroy_local Counter Total connections destroyed due to local close
downstream_cx_destroy_active_rq Counter Total connections destroyed with 1+ active request
downstream_cx_destroy_local_active_rq Counter Total connections destroyed locally with 1+ active request
downstream_cx_destroy_remote_active_rq Counter Total connections destroyed remotely with 1+ active request
downstream_cx_active Gauge Total active connections
downstream_cx_ssl_active Gauge Total active TLS connections
downstream_cx_http1_active Gauge Total active HTTP/1.1 connections
downstream_cx_websocket_active Gauge Total active WebSocket connections
downstream_cx_http2_active Gauge Total active HTTP/2 connections
downstream_cx_protocol_error Counter Total protocol errors
downstream_cx_length_ms Histogram Connection length milliseconds
downstream_cx_rx_bytes_total Counter Total bytes received
downstream_cx_rx_bytes_buffered Gauge Total received bytes currently buffered
downstream_cx_tx_bytes_total Counter Total bytes sent
downstream_cx_tx_bytes_buffered Gauge Total sent bytes currently buffered
downstream_cx_drain_close Counter Total connections closed due to draining
downstream_cx_idle_timeout Counter Total connections closed due to idle timeout
downstream_flow_control_paused_reading_total Counter Total number of times reads were disabled due to flow control
downstream_flow_control_resumed_reading_total Counter Total number of times reads were enabled on the connection due to flow control
downstream_rq_total Counter Total requests
downstream_rq_http1_total Counter Total HTTP/1.1 requests
downstream_rq_http2_total Counter Total HTTP/2 requests
downstream_rq_active Gauge Total active requests
downstream_rq_response_before_rq_complete Counter Total responses sent before the request was complete
downstream_rq_rx_reset Counter Total request resets received
downstream_rq_tx_reset Counter Total request resets sent
downstream_rq_non_relative_path Counter Total requests with a non-relative HTTP path
downstream_rq_too_large Counter Total requests resulting in a 413 due to buffering an overly large body
downstream_rq_completed Counter Total requests that resulted in a response (e.g. does not include aborted requests)
downstream_rq_1xx Counter Total 1xx responses
downstream_rq_2xx Counter Total 2xx responses
downstream_rq_3xx Counter Total 3xx responses
downstream_rq_4xx Counter Total 4xx responses
downstream_rq_5xx Counter Total 5xx responses
downstream_rq_ws_on_non_ws_route Counter Total WebSocket upgrade requests rejected by non WebSocket routes
downstream_rq_time Histogram Request time milliseconds
downstream_rq_idle_timeout Counter Total requests closed due to idle timeout
downstream_rq_overload_close Counter Total requests closed due to envoy overload
rs_too_large Counter Total response errors due to buffering an overly large body

Per user agent statistics

Additional per user agent statistics are rooted at http.<stat_prefix>.user_agent.<user_agent>. Currently Envoy matches user agent for both iOS (ios) and Android (android) and produces the following statistics:

Name Type Description
downstream_cx_total Counter Total connections
downstream_cx_destroy_remote_active_rq Counter Total connections destroyed remotely with 1+ active requests
downstream_rq_total Counter Total requests

Per listener statistics

Additional per listener statistics are rooted at listener.<address>.http.<stat_prefix>. with the following statistics:

Name Type Description
downstream_rq_completed Counter Total responses
downstream_rq_1xx Counter Total 1xx responses
downstream_rq_2xx Counter Total 2xx responses
downstream_rq_3xx Counter Total 3xx responses
downstream_rq_4xx Counter Total 4xx responses
downstream_rq_5xx Counter Total 5xx responses

Per codec statistics

Each codec has the option of adding per-codec statistics. Currently only http2 has codec stats.

Http2 codec statistics

All http2 statistics are rooted at http2.

Name Type Description
header_overflow Counter Total number of connections reset due to the headers being larger than Envoy::Http::Http2::ConnectionImpl::StreamImpl::MAX_HEADER_SIZE (63k)
headers_cb_no_stream Counter Total number of errors where a header callback is called without an associated stream. This tracks an unexpected occurrence due to an as yet undiagnosed bug
rx_messaging_error Counter Total number of invalid received frames that violated section 8 of the HTTP/2 spec. This will result in a tx_reset
rx_reset Counter Total number of reset stream frames received by Envoy
too_many_header_frames Counter Total number of times an HTTP2 connection is reset due to receiving too many headers frames. Envoy currently supports proxying at most one header frame for 100-Continue one non-100 response code header frame and one frame with trailers
trailers Counter Total number of trailers seen on requests coming from downstream
tx_reset Counter Total number of reset stream frames transmitted by Envoy

Tracing statistics

Tracing statistics are emitted when tracing decisions are made. All tracing statistics are rooted at http.<stat_prefix>.tracing. with the following statistics:

Name Type Description
random_sampling Counter Total number of traceable decisions by random sampling
service_forced Counter Total number of traceable decisions by server runtime flag tracing.global_enabled
client_enabled Counter Total number of traceable decisions by request header x-envoy-force-trace
not_traceable Counter Total number of non-traceable decisions by request id
health_check Counter Total number of non-traceable decisions by health check